MedWorm.com provides a medical RSS filtering service. Over 6000 RSS medical sources are combined and output via different filters. This feed contains the latest items from the 'The Biological Bulletin' source. Fri, 27 Jan 2012 14:49:01 +0100 http://www.medworm.com/index.php?rid=5544566&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22186911%26dopt%3DAbstract Authors: Hofstee J, Pernet B PMID: 22186911 [PubMed - in process] (Source: The Biological Bulletin) The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=5544566 Thu, 01 Dec 2011 05:00:00 +0100 5544566 http://www.medworm.com/index.php?rid=5544565&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22186912%26dopt%3DAbstract Authors: Ohtsu K, Uye S PMID: 22186912 [PubMed - in process] (Source: The Biological Bulletin) The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=5544565 Thu, 01 Dec 2011 05:00:00 +0100 5544565 http://www.medworm.com/index.php?rid=5544564&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22186913%26dopt%3DAbstract Authors: Ikeda H, Ohtsu K, Uye S Abstract Production of podocysts is the exclusive form of asexual reproduction by polyps of the giant jellyfish Nemopilema nomurai, which has been recurrently blooming in the East Asian seas in the last decade. Podocycts consist of a dome-shaped chitinous capsule with laminated structure that encapsulates a mass of cyst cells filled with granules containing nutrient reserves such as proteins, carbohydrates, and lipids. Mitochondria, rough endoplasmic reticulum, and Golgi complexes are scarce in the cytoplasm of these cells, and the staining reaction for RNA is weak, indicating very low metabolic activity. Podocysts are capable of dormancy for at least 5 years without significant change of internal structure or nutrient reserves. Integrated informati... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=5544564 Thu, 01 Dec 2011 05:00:00 +0100 5544564 http://www.medworm.com/index.php?rid=5544563&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22186914%26dopt%3DAbstract This study explores the role of sphingosine rheostat components in the stability of the symbiotic partnership. The anemone Aiptasia pallida, host to the dinoflagellate Symbiodinium sp., was used to test the hypothesis that S1P promotes symbiosis stability whereas Sph increases bleaching induced by heat stress. Anemones pre-incubated in exogenous S1P and FTY720, a synthetic S1P analog, were partially rescued from heat-stress-induced bleaching. In addition, they displayed a decrease in caspase activity, a measure of apoptosis, compared to controls. In contrast, when anemones were pre-incubated with Sph, both bleaching and caspase activity increased compared to untreated, heat-stressed controls. These data suggest that the sphingosine rheostat may play a role in the balance between stability ... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=5544563 Thu, 01 Dec 2011 05:00:00 +0100 5544563 http://www.medworm.com/index.php?rid=5544562&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22186915%26dopt%3DAbstract Authors: Goldenheim WM, Edmunds PJ Abstract To test for threshold effects in the response of coral physiology to increasing seawater flow, field and laboratory experiments were conducted in Moorea. First, the growth of juvenile massive Porites spp. and branching P. irregularis was compared among habitats differing in water motion. Growth of massive Porites spp. responded to flow in a pattern consistent with a threshold effect, whereas growth of P. irregularis increased linearly with flow. Second, a recirculating flume was used to test the effect of flow on photophysiology (ΔF/F(m)', effective photochemical efficiency) for massive Porites spp.; ΔF/F(m)' displayed a threshold response at 23 cm s(-1) and 28 °C, but not at 31 °C. Finally, intra-colony variation in the response of Î... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=5544562 Thu, 01 Dec 2011 05:00:00 +0100 5544562 http://www.medworm.com/index.php?rid=5544561&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22186916%26dopt%3DAbstract Authors: Motokawa T Abstract Stiffness changes in response to mechanical and chemical stimulation were studied in muscle-free dermal samples from the body wall of the starfish Linckia laevigata. The ultrastructural study showed that the dermis was packed with collagen fibrils between which only a small number of cells were observed. Muscles were found only in the walls of coelomic extensions leading to papulae. Stress-strain tests were performed on isolated dermis containing no muscles. The tangent modulus was 27.5 MPa at 0.04% strain rate in the stress-strain tests. It was increased to 40.7 MPa by mechanical stimulation, which also increased the tensile strength and breaking-strain energy density. Dynamic mechanical tests showed that the increase in stiffness in response to mechan... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=5544561 Thu, 01 Dec 2011 05:00:00 +0100 5544561 http://www.medworm.com/index.php?rid=5544560&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22186917%26dopt%3DAbstract Authors: Wang Q, Fang DA, Li WW, Wang J, Jiang H Abstract The translationally controlled tumor protein (TCTP), which was initially described as a growth-related protein, primarily expresses proteins for numerous biological processes in eukaryotes. In the present study, the TCTP gene in the Chinese mitten crab Eriocheir sinensis (Es-TCTP) was identified from tissues of the hepatopancreas, by the construction of a cDNA library and the rapid amplification of cDNA ends. The results showed that the full length of Es-TCTP cDNA comprises 727 nucleotides, with an open reading frame of 507 bp that encodes 168 amino acid residues. The deduced amino acid sequence of Es-TCTP has a 51%-92% similarity to TCTPs of other eukaryotic species. The mRNA transcripts of Es-TCTP were detected by using RT... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=5544560 Thu, 01 Dec 2011 05:00:00 +0100 5544560 http://www.medworm.com/index.php?rid=5544559&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22186918%26dopt%3DAbstract Authors: Sulkowski MJ, Kurosawa MS, Cox DN Abstract The ability to perceive and avoid harmful substances or stimuli is key to an organism's survival. The neuronal cognate of the perception of pain is known as nociception, and the reflexive motion to avoid pain is termed the nocifensive response. As the nocifensive response is an ancient and evolutionarily conserved behavioral response to nociceptive stimuli, it is amenable to study in relatively simple and genetically tractable model systems such as Drosophila. Recent studies have taken advantage of the useful properties of Drosophila larvae to begin elucidating the neuronal connectivity and molecular machinery underlying the nocifensive response. However, these studies have primarily utilized the third-instar larval stage, and man... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=5544559 Thu, 01 Dec 2011 05:00:00 +0100 5544559 http://www.medworm.com/index.php?rid=5544558&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22186919%26dopt%3DAbstract Authors: Higgs ND, Glover AG, Dahlgren TG, Little CT Abstract Osedax worms possess unique "root" tissues that they use to bore into bones on the seafloor, but details of the boring pattern and processes are poorly understood. Here we use X-ray micro-computed tomography to investigate the borings of Osedax mucofloris in bones of the minke whale (Balaenoptera acutorostrata), quantitatively detailing their morphological characteristics for the first time. Comparative thin-sections of the borings reveal how the bone is eroded at the sub-millimeter level. On the basis of these results we hypothesize a model of boring that is dependent on the density and microstructure of the bone. We also present evidence of acidic mucopolysaccharides in the mucus of the root tissue, and hypothesize tha... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=5544558 Thu, 01 Dec 2011 05:00:00 +0100 5544558 http://www.medworm.com/index.php?rid=5544557&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22186920%26dopt%3DAbstract Authors: PMID: 22186920 [PubMed - in process] (Source: The Biological Bulletin) The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=5544557 Thu, 01 Dec 2011 05:00:00 +0100 5544557 http://www.medworm.com/index.php?rid=5376729&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22042433%26dopt%3DAbstract This study investigates such microsatellite distributions in the genome of the economically important abalone Haliotis midae, via a bioinformatic survey. In particular, the association of specific repeat motifs to coding regions and transposable elements is investigated. An understanding of microsatellite genomic distribution will facilitate more efficient use and development of this popular molecular marker. A bias toward di- and tetranucleotide repeats was found in the H. midae genome. CA microsatellite units were the most abundant repeat motif, but were notably underrepresented in genic regions where GAGT repeats predominate. Approximately 17.5% and 21% of the microsatellites showed gene and/or transposable element associations, respectively. This could explain the high genomic frequenc... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=5376729 Sat, 01 Oct 2011 04:00:00 +0100 5376729 http://www.medworm.com/index.php?rid=5376728&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22042434%26dopt%3DAbstract Authors: Denny M, Dorgan KM, Evangelista D, Hettinger A, Leichter J, Ruder WC, Tuval I Abstract Sea ice typically forms at the ocean's surface, but given a source of supercooled water, an unusual form of ice-anchor ice-can grow on objects in the water column or at the seafloor. For several decades, ecologists have considered anchor ice to be an important agent of disturbance in the shallow-water benthic communities of McMurdo Sound, Antarctica, and potentially elsewhere in polar seas. Divers have documented anchor ice in the McMurdo communities, and its presence coincides with reduced abundance of the sponge Homaxinella balfourensis, which provides habitat for a diverse assemblage of benthic organisms. However, the mechanism of this disturbance has not been explored. Here we show i... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=5376728 Sat, 01 Oct 2011 04:00:00 +0100 5376728 http://www.medworm.com/index.php?rid=5376727&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22042435%26dopt%3DAbstract Authors: Johnson NG, Burnett LE, Burnett KG Abstract In the blue crab Callinectes sapidus, injection with the bacterial pathogen Vibrio campbellii causes a decrease in oxygen consumption. Histological and physiological evidence suggests that the physical obstruction of hemolymph flow through the gill vasculature, caused by aggregations of bacteria and hemocytes, underlies the decrease in aerobic function associated with bacterial infection. We sought to elucidate the bacterial properties sufficient to induce a decrease in circulating hemocytes (hemocytopenia) as an indicator for the initiation of hemocyte aggregation and subsequent impairment of respiration. Lipopolysaccharide (LPS), the primary component of the gram-negative bacterial cell wall, is known to interact with crustacea... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=5376727 Sat, 01 Oct 2011 04:00:00 +0100 5376727 http://www.medworm.com/index.php?rid=5376726&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22042436%26dopt%3DAbstract Authors: Page LR Abstract I used histological sections and 3D reconstructions to document development through metamorphosis of the foregut and proboscis in the conoidean neogastropod Conus lividus. A goal was to determine how highly derived features of the post-metamorphic feeding system of this gastropod predator develop without interfering with larval structures for microherbivory. A second goal was to compare foregut development in this conoidean with previous observations on foregut development in the buccinoidean neogastropod Nassarius mendicus. These two neogastropods both have a feeding larval stage, but they show major differences in post-metamorphic foregut morphology. Basic events in development of the proboscis and proboscis sheath in C. lividus and N. mendicus were simi... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=5376726 Sat, 01 Oct 2011 04:00:00 +0100 5376726 http://www.medworm.com/index.php?rid=5376724&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22042437%26dopt%3DAbstract In this study, a population of the opisthobranch gastropod Haminoea zelandiae from Pauatahanui Inlet, New Zealand, was found to exhibit poecilogony. Further, differences in development, hatching times and proportion of hatchlings that were veligers or juveniles were examined for egg masses in two temperature regimes in the laboratory: cool (15-17 °C), and warm (21-23 °C). Hatching proportions were also examined for egg masses collected from the field (where temperatures ranged from 21-23 °C) for varying lengths of time (1 d, 5 d, and 10 d post-spawning). Hatchlings from egg masses in warmer temperatures developed faster and hatched earlier than those in cool temperatures. In the laboratory, egg masses in warm conditions hatched a greater proportion of post-metamorphic juveniles (45.4%) ... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=5376724 Sat, 01 Oct 2011 04:00:00 +0100 5376724 http://www.medworm.com/index.php?rid=5376719&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22042438%26dopt%3DAbstract Authors: Quilichini Y, Foata J, Justine JL, Bray RA, Marchand B Abstract The ultrastructure of the mature spermatozoon of Gyliauchen sp., a parasite of the dusky rabbitfish Siganus fuscescens, was studied by transmission electron microscopy. The spermatozoon possesses two axonemes of the 9+"1" pattern of Trepaxonemata, four attachment zones, one mitochondrion, a nucleus, cortical microtubules, external ornamentation of the plasma membrane, and spine-like bodies. The main characteristics of this spermatozoon are the presence of one mitochondrion, spine-like bodies not associated with the external ornamentation, and a posterior extremity of type 3 that is characterized by the following sequence: posterior extremity of the nucleus then posterior extremity of the second axoneme. Numero... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=5376719 Sat, 01 Oct 2011 04:00:00 +0100 5376719 http://www.medworm.com/index.php?rid=5376718&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22042439%26dopt%3DAbstract Authors: Ito A, Aoki MN, Yahata K, Wada H Abstract The Caprellidea generally possess rudimentary abdomens and degenerated third and fourth pereopods. Previous molecular phylogenetic studies support the concept that their unique body plan is derived from a gammarid-like body plan from which the abdomen or third and fourth pereopods have been lost in the Caprellidea. To understand the developmental and genetic mechanisms for the morphological evolution of the Caprellidea, we observed the embryonic development of Caprella scaura. Although in the early embryonic stage limb buds appeared in all of the pereonites, we found that elongation of the limb buds did not occur in the third and fourth pereonites; instead, only oval projections (possibly primordial gills) were observed. We next ex... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=5376718 Sat, 01 Oct 2011 04:00:00 +0100 5376718 http://www.medworm.com/index.php?rid=5376717&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22042440%26dopt%3DAbstract Authors: Longley RD Abstract The procerebrum, a specialized structure for olfaction in terrestrial pulmonate molluscs, contains 20,000 to 50,000 small, uniformly sized neurons that increase in number with age. Here I show the likely source of neurons added to the procerebrum of Helix aspersa and that the rate of neuron addition depends on snail weight. After hatching, during the initial exponential growth phase, H. aspersa adds neurons to the procerebral apex by mitosis and from a cerebral tube. In the logistic growth phase beginning 30-40 days post-hatch, neurons also seem to be added to the procerebrum from the peritentacular and olfactory nerves, causing the rate of neuron addition to approximately double; but as in the earlier exponential growth phase, this rate remains a funct... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=5376717 Sat, 01 Oct 2011 04:00:00 +0100 5376717 http://www.medworm.com/index.php?rid=5376716&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22042441%26dopt%3DAbstract Authors: Unuma T, Sawaguchi S, Yamano K, Ohta H Abstract Sea urchins of both sexes store the nutrients necessary for gametogenesis in nutritive phagocytes of the agametogenic gonad. A zinc-binding protein termed the major yolk protein (MYP) is stored here as two isoforms: the egg-type (predominant in egg yolk granules) and the coelomic fluid-type (a precursor with greater zinc-binding capacity). MYP is used during gametogenesis as material for synthesizing gametic proteins and other components. We investigated its accumulation and relationship to zinc contents in gonads during the non-reproductive season in Pseudocentrotus depressus. MYP constituted most of the protein in coelomic fluid and gonads. Both ovaries and testes grew gradually, accumulating MYP and zinc during the year. T... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=5376716 Sat, 01 Oct 2011 04:00:00 +0100 5376716 http://www.medworm.com/index.php?rid=5188638&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21876106%26dopt%3DAbstract Authors: Smith J, Olds JL PMID: 21876106 [PubMed - in process] (Source: The Biological Bulletin) The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=5188638 Sun, 31 Jul 2011 23:00:00 +0100 5188638 http://www.medworm.com/index.php?rid=5188637&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21876107%26dopt%3DAbstract Authors: Morgan TH Abstract With the publication of the data here presented the series of experiments that I have carried out on Tubularia for several years may be considered as temporarily brought to a close. I take this opportunity therefore to sum up the evidence bearing on the problem of the formative factors of regeneration, as exhibited by this hydroid. In the course of my experiments tentative hypotheses have been proposed here and there that have at least served to suggest further experiments. The conflicting evidence sometimes inclined me towards one point of view, sometimes towards another; yet, all in all, the same general line of thought, if sometimes vague, can be traced through the attempts to analyze the results. It will be my endeavor here to bring more into the for... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=5188637 Sun, 31 Jul 2011 23:00:00 +0100 5188637 http://www.medworm.com/index.php?rid=5188636&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21876108%26dopt%3DAbstract Authors: Smith J, Morgan JR, Zottoli SJ, Smith PJ, Buxbaum JD, Bloom OE Abstract What gives an organism the ability to regrow tissues and to recover function where another organism fails is the central problem of regenerative biology. The challenge is to describe the mechanisms of regeneration at the molecular level, delivering detailed insights into the many components that are cross-regulated. In other words, a broad, yet deep dissection of the system-wide network of molecular interactions is needed. Functional genomics has been used to elucidate gene regulatory networks (GRNs) in developing tissues, which, like regeneration, are complex systems. Therefore, we reason that the GRN approach, aided by next generation technologies, can also be applied to study the molecular mechanism... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=5188636 Sun, 31 Jul 2011 23:00:00 +0100 5188636 http://www.medworm.com/index.php?rid=5188635&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21876109%26dopt%3DAbstract Authors: Matsuo R, Ito E Abstract Of all organs in mammals including humans, the brain has the most limited regenerative capacity after injury or damage. In spite of extensive efforts to treat ischemic/stroke injury of the brain, thus far no reliable therapeutic method has been developed. However, some molluscan species show remarkable brain regenerative ability and can achieve full functional recovery following injury. The terrestrial pulmonates are equipped with a highly developed olfactory center, called the procerebrum, which is involved in olfactory discrimination and odor-aversion learning. Recent studies revealed that the procerebrum of the land slug can spontaneously recover structurally and functionally relatively soon after injury. Surprisingly, no exogenous interventions... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=5188635 Sun, 31 Jul 2011 23:00:00 +0100 5188635 http://www.medworm.com/index.php?rid=5188634&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21876110%26dopt%3DAbstract Authors: Kürn U, Rendulic S, Tiozzo S, Lauzon RJ Abstract Regeneration is widely distributed among the metazoans. However, clear differences exist as to the degree of regenerative capacity: some phyla can only replace missing body parts, whereas others can generate entirely new individuals. Ascidians are animals that possess a remarkable regenerative plasticity and exhibit a great diversity of mechanisms for asexual propagation and survival. They are marine invertebrate members of the subphylum Tunicata and represent modern-day descendants of the chordate ancestor; in their tadpole stage they exhibit a chordate body plan that is resorbed during metamorphosis. Solitary species grow into an adult that can reach several centimeters in length, whereas colonial species grow by asexual ... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=5188634 Sun, 31 Jul 2011 23:00:00 +0100 5188634 http://www.medworm.com/index.php?rid=5188633&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21876111%26dopt%3DAbstract Authors: Yoshinari N, Kawakami A Abstract The multitude of cells constituting organisms are fragile and easily damaged day by day. Therefore, maintenance of tissue morphology and function is fundamental for multicellular organisms to attain long life. For proper maintenance of tissue integrity, organisms must have mechanisms that detect the loss of tissue mass, activate the de novo production of cells, and organize those cells into functional tissues. However, these processes are only poorly understood. Here we give an overview of adult and juvenile tissue regeneration models in small fish species, such as zebrafish and medaka, and highlight recent advances at the molecular level. From these advances, we have come to realize that the epidermal and mesenchymal parts of the regenerat... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=5188633 Sun, 31 Jul 2011 23:00:00 +0100 5188633 http://www.medworm.com/index.php?rid=5188628&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21876112%26dopt%3DAbstract Authors: Messerli MA, Graham DM Abstract Endogenous DC electric fields (EFs) are important, fundamental components of development, regeneration, and wound healing. The fields are the result of polarized ion transport and current flow through electrically conductive pathways. Nullification of endogenous EFs with pharmacological agents or applied EFs of opposite polarity disturbs the aforementioned processes, while enhancement increases the rate of wound closure and the extent of regeneration. EFs are applied to humans in the clinic, to provide an overwhelming signal for the enhancement of healing of chronic wounds. Although clinical trials, spanning a course of decades, have shown that applied EFs enhance healing of chronic wounds, the mechanisms by which cells sense and respond to ... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=5188628 Sun, 31 Jul 2011 23:00:00 +0100 5188628 http://www.medworm.com/index.php?rid=5188627&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21876113%26dopt%3DAbstract Authors: Mashanov VS, García-Arrarás JE Abstract Visceral regeneration in sea cucumbers has been studied since early last century; however, it is only within the last 15 years that real progress has been made in understanding the cellular and molecular events involved. In the present review, we bring together these recent studies, providing readers with basic information on the anatomy and histology of the normal gut and detailing the changes in tissue organization and gene expression that occur during the regenerative process. We discuss the nature and possible sources of cells involved in the formation of the intestinal regenerate as well as the role of cell death and proliferation in this process. In addition, we compare gut formation during regeneration and during embryogenes... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=5188627 Sun, 31 Jul 2011 23:00:00 +0100 5188627 http://www.medworm.com/index.php?rid=5188626&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21876114%26dopt%3DAbstract Authors: Turner MB, Szabo-Maas TM, Poyer JC, Zoran MJ Abstract Regeneration of motor systems involves reestablishment of central control networks, reinnervation of muscle targets by motoneurons, and reconnection of neuromodulatory circuits. Still, how these processes are integrated as motor function is restored during regeneration remains ill defined. Here, we examined the mechanisms underlying motoneuronal regeneration of neuromuscular synapses related to feeding movements in the pulmonate snail Helisoma trivolvis. Neurons B19 and B110, although activated during different phases of the feeding pattern, innervate similar sets of muscles. However, the percentage of muscle fibers innervated, the efficacy of excitatory junction potentials, and the strength of muscle contractions were ... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=5188626 Sun, 31 Jul 2011 23:00:00 +0100 5188626 http://www.medworm.com/index.php?rid=5188625&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21876115%26dopt%3DAbstract Authors: Sköld HN, Stach T, Bishop JD, Herbst E, Thorndyke MC Abstract Many invertebrates reproduce asexually by budding, but morphogenesis and the role of cell proliferation in this diverse and nonconserved regeneration-like process are generally poorly understood and particularly little investigated in didemnid ascidians. We here analyzed cell proliferation patterns and telomerase activity during budding in the colonial didemnid ascidian Diplosoma listerianum, with special focus on the thoracic bud where a new brain develops de novo. To help define developmental stages of the thoracic bud, the distribution of acetylated tubulin was also examined. We found extensive cell proliferation in both the thoracic and abdominal buds of D. listerianum as well as higher telomerase activity ... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=5188625 Sun, 31 Jul 2011 23:00:00 +0100 5188625 http://www.medworm.com/index.php?rid=5188624&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21876116%26dopt%3DAbstract Authors: Fukui L, Henry JJ Abstract In species of the frog genus Xenopus, lens regeneration occurs through a process of transdifferentiation, in which cornea epithelial cells presumably undergo dedifferentiation and subsequently redifferentiate to form a new lens. Experimental studies have shown that the retina provides the key signal required to trigger this process once the original lens is removed. A previous study showed that addition of an exogenous fibroblast growth factor (i.e., FGF1 protein) could initiate transdifferentiation of cornea epithelial cells in culture. To determine the role of FGF signaling in X. laevis lens regeneration, we have examined the presence of specific FGFs and their receptors (FGFRs) during this process and evaluated the necessity of FGFR signaling.... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=5188624 Sun, 31 Jul 2011 23:00:00 +0100 5188624 http://www.medworm.com/index.php?rid=4996342&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21712224%26dopt%3DAbstract This study examined the effects of 5-HT on locomotion in the nudibranch mollusc Melibe leonina (Gould, 1852). M. leonina exhibits two modes of locomotion, crawling and swimming. Animals were bath-immersed in a range of concentrations of 5-HT or injected with various 5-HT solutions into the hemolymph and then monitored for locomotor activity. In contrast to other gastropods studied, M. leonina showed no significant effect of 5-HT on the distance crawled or the speed of crawling. However, the highest concentration (10(-3) mol l(-1) for bath immersion and 10(-5) mol l(-1) for injection) significantly increased the time spent swimming and the swimming speed. The 5-HT receptor antagonist methysergide inhibited the influence of 5-HT on the overall amount of swimming but not on swimming speed. Th... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=4996342 Tue, 31 May 2011 23:00:00 +0100 4996342 http://www.medworm.com/index.php?rid=4996341&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21712225%26dopt%3DAbstract Authors: Boch CA, Ananthasubramaniam B, Sweeney AM, Doyle FJ, Morse DE Synchrony of spawning in many hermatypic corals, typically a few nights after the full moon, is putatively dependent on solar and lunar light cycles in conjunction with other possible cues such as tides and temperature. We analyze here the contributions of separate components of light dynamics, because the effects of twilight and lunar skylight on coral spawning synchrony have previously been conflated and the alternative hypothesis that these components have differential contributions as proximate cues has not been tested. Moonlight-dependent changes in spectra during twilight, rates of decreasing twilight intensities, and changes in lunar photoperiod were experimentally decoupled using programmed light-emitting di... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=4996341 Tue, 31 May 2011 23:00:00 +0100 4996341 http://www.medworm.com/index.php?rid=4996340&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21712226%26dopt%3DAbstract In this study we demonstrate that extracts of egg jelly contain factors that extend the period of sperm motility as well as providing a chemoattractant activity as previously reported. Both activities are partially dependent on extracellular calcium. Time-lapse and video microscopy show that after activation of motility the number of motile sperm decreases rapidly, with a half-time of about 2 min. Addition of 10% v/v egg jelly extract ("egg water") increased the number of motile sperm 2-fold over controls at 20 s and about 4- to 10-fold over controls at 10 min after initiation of motility. Extension of motility lifetime was not mediated by a nonspecific protein or by allurin, the egg-water protein that has chemoattractant activity. The helical path of Xenopus sperm exhibited tight coupling... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=4996340 Tue, 31 May 2011 23:00:00 +0100 4996340 http://www.medworm.com/index.php?rid=4996339&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21712227%26dopt%3DAbstract Authors: Pernet B, Strathmann RR The larvae of marine annelids capture food using an unusual diversity of suspension-feeding mechanisms. Many of the feeding mechanisms of larval annelids are poorly known despite the abundance and ecological significance of both larvae and adults of some annelid taxa. Here we show that larvae of two species of sabellariid annelids, Sabellaria cementarium and Phragmatopoma californica, bear prototrochal and metatrochal cilia that beat in opposition to each other. For larvae of S. cementarium, we provide evidence that these opposed bands of cilia are used to capture suspended particles. In video recordings, captured particles were overtaken by a prototrochal cilium and then moved with the cilium to the food groove, a band of cilia between the prototroch a... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=4996339 Tue, 31 May 2011 23:00:00 +0100 4996339 http://www.medworm.com/index.php?rid=4996338&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21712228%26dopt%3DAbstract Authors: Sanders JG, Palumbi SR Among temperate cnidarian symbioses, the partnership between the intertidal anemone Anthopleura elegantissima and its dinoflagellate and chlorophyte symbionts is one of the most well characterized. Biogeographic, reciprocal transplant, and physiological studies have convincingly demonstrated a relationship between environmental factors such as temperature and irradiance and the distribution of symbionts from both algal phyla. However, little is known about the fine-scale diversity or biogeographic distribution within symbiont lineages of this anemone. We used sequence information from the mitochondrial cytochrome b and chloroplast 23S ribosomal genes and restriction fragment length polymorphism data from the 18S nuclear ribosomal gene to characterize the... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=4996338 Tue, 31 May 2011 23:00:00 +0100 4996338 http://www.medworm.com/index.php?rid=4996337&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21712229%26dopt%3DAbstract Authors: Miller LP, Denny MW For organisms living in the intertidal zone, temperature is an important selective agent that can shape species distributions and drive phenotypic variation among populations. Littorinid snails, which occupy the upper limits of rocky shores and estuaries worldwide, often experience extreme high temperatures and prolonged aerial emersion during low tides, yet their robust physiology-coupled with morphological and behavioral traits-permits these gastropods to persist and exert strong grazing control over algal communities. We use a mechanistic heat-budget model to compare the effects of behavioral and morphological traits on the body temperatures of five species of littorinid snails under natural weather conditions. Model predictions and field experiments ind... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=4996337 Tue, 31 May 2011 23:00:00 +0100 4996337 http://www.medworm.com/index.php?rid=4996336&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21712230%26dopt%3DAbstract Authors: Carlo JM, Barbeitos MS, Lasker HR Species descriptions of most alcyonacean octocorals rely heavily on the morphology of sclerites, the calcium carbonate spicules embedded in the soft tissue. Sclerites provide taxonomic characters for species delineation but require qualitative descriptions, which introduce ambiguities in recognizing morphological features. Elliptical Fourier analysis of the outline of sclerites was used to quantify the morphology of eight species of gorgoniid octocoral in the genus Pseudopterogorgia. Sclerites from one to seven colonies of each species were compared. Scaphoids and spindles were examined separately; rods and octoradiates were excluded from the analyses because of their morphologic similarity across all species. Discriminant analysis of elliptic... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=4996336 Tue, 31 May 2011 23:00:00 +0100 4996336 http://www.medworm.com/index.php?rid=4996335&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21712231%26dopt%3DAbstract Authors: PMID: 21712231 [PubMed - in process] (Source: The Biological Bulletin) The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=4996335 Tue, 31 May 2011 23:00:00 +0100 4996335 http://www.medworm.com/index.php?rid=4851249&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21551443%26dopt%3DAbstract Authors: Morowitz HJ PMID: 21551443 [PubMed - in process] (Source: The Biological Bulletin) The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=4851249 Thu, 31 Mar 2011 23:00:00 +0100 4851249 http://www.medworm.com/index.php?rid=4851247&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21551444%26dopt%3DAbstract Authors: Jackson E, Johnsen S PMID: 21551444 [PubMed - in process] (Source: The Biological Bulletin) The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=4851247 Thu, 31 Mar 2011 23:00:00 +0100 4851247 http://www.medworm.com/index.php?rid=4851245&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21551445%26dopt%3DAbstract Authors: Pekkurnaz G, Fera A, Zimmerberg-Helms J, Degiorgis JA, Bezrukov L, Blank PS, Mazar J, Reese TS, Zimmerberg J Synaptic vesicles contain a variety of proteins and lipids that mediate fusion with the pre-synaptic membrane. Although the structures of many synaptic vesicle proteins are known, an overall picture of how they are organized at the vesicle surface is lacking. In this paper, we describe a better method for the isolation of squid synaptic vesicles and characterize the results. For highly pure and intact synaptic vesicles from squid optic lobe, glycerol density gradient centrifugation was the key step. Different electron microscopic methods show that vesicle membrane surfaces are largely covered with structures corresponding to surface proteins. Each vesicle contains sever... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=4851245 Thu, 31 Mar 2011 23:00:00 +0100 4851245 http://www.medworm.com/index.php?rid=4851243&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21551446%26dopt%3DAbstract This study gives insights into the influence of host physiology on glochidial attachment and juvenile mussel transformation. PMID: 21551446 [PubMed - in process] (Source: The Biological Bulletin) The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=4851243 Thu, 31 Mar 2011 23:00:00 +0100 4851243 http://www.medworm.com/index.php?rid=4851241&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21551447%26dopt%3DAbstract Authors: Tepler S, Mach K, Denny M Evolutionary theory predicts that, in variable environments, it is advantageous for ectothermic organisms to prefer a body temperature slightly below the physiological optimum. This theory works well for many terrestrial organisms but has not been tested for animals inhabiting the hypervariable physical environment of intertidal shores. In laboratory experiments, we allowed the intertidal snail Chlorostoma funebralis to position itself on a temperature gradient, then measured its thermal preference and determined an index of how its performance varied with temperature. Snails performed a biased random walk along the temperature gradient, which, contrary to expectations, caused them to aggregate where body temperature was 15 to 17 °C below their tempe... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=4851241 Thu, 31 Mar 2011 23:00:00 +0100 4851241 http://www.medworm.com/index.php?rid=4851239&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21551448%26dopt%3DAbstract Authors: Bates AE, Harmer TL, Roeselers G, Cavanaugh CM Marine invertebrates hosting chemosynthetic bacterial symbionts are known from multiple phyla and represent remarkable diversity in form and function. The deep-sea hydrothermal vent limpet Lepetodrilus fucensis from the Juan de Fuca Ridge complex hosts a gill symbiosis of particular interest because it displays a morphology unique among molluscs: filamentous bacteria are found partially embedded in the host's gill epithelium and extend into the fluids circulating across the lamellae. Our objective was to investigate the phylogenetic affiliation of the limpet's primary gill symbionts for comparison with previously characterized bacteria. Comparative 16S rRNA sequence analysis identified one γ- and three ε-Proteobacteria as candid... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=4851239 Thu, 31 Mar 2011 23:00:00 +0100 4851239 http://www.medworm.com/index.php?rid=4851238&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21551449%26dopt%3DAbstract In this study we provide morphological evidence that in Osedax the bacteriocytes are derived from somatic mesoderm. We show that the trophosome in Osedax is an apolar tissue composed of bacteriocytes and nonsymbiotic cells. As in vestimentiferans, a specific cell cycle was identified; however, in this case it is directed from the posterior to the anterior end of the worms instead of from the center toward the periphery. Comparison of all siboglinid trophosomes and re-evaluation of their body regions allows us to discuss whether the trophosomes are homologous and to hypothesize about the organization of the last common ancestor of Siboglinidae. PMID: 21551449 [PubMed - in process] (Source: The Biological Bulletin) The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=4851238 Thu, 31 Mar 2011 23:00:00 +0100 4851238 http://www.medworm.com/index.php?rid=4851235&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21551450%26dopt%3DAbstract This study reveals that the Sclerolinum trophosome exhibits two regions that differ in the organization of host tissue and the size and shape of the symbionts. We suggest that a specific cell cycle within the symbiont-housing organ is directed along the longitudinal body axis, with a region of proliferation anteriorly and a region of degradation posteriorly. Using Raman microspectroscopy we demonstrate that the endosymbionts of S. contortum from the Gulf of Mexico contain sulfur vesicles, and we argue for a chemoautotrophic sulfur-oxidizing metabolism. PMID: 21551450 [PubMed - in process] (Source: The Biological Bulletin) The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=4851235 Thu, 31 Mar 2011 23:00:00 +0100 4851235 http://www.medworm.com/index.php?rid=4571653&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21385951%26dopt%3DAbstract Authors: Himes JE, Riffell JA, Zimmer CA, Zimmer RK Fertilization is one of the least understood fundamental biological processes. How sperm search for and find an egg remains enigmatic. Sperm attraction to egg-derived chemical cues may be significant evolutionarily for maintaining species barriers and important ecologically for increasing gamete encounters. New tools are needed, however, to resolve the functional consequences of these dissolved signal molecules. Freshly spawned eggs from red abalone (Haliotis rufescens) naturally release l-tryptophan, which stimulates chemotactic responses by conspecific sperm. Here, microspheres were manufactured to the approximate size and the same shape as female gametes and formulated to emit controlled doses of chemoattractant, imitating natural ... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=4571653 Tue, 01 Feb 2011 00:00:00 +0100 4571653 http://www.medworm.com/index.php?rid=4571652&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21385952%26dopt%3DAbstract We examined changes in the bell morphology and swimming kinematics of the limnomedusa Liriope tetraphylla at different stages of development. L. tetraphylla maintained an oblate bell (fineness ratio ≈ 0.5-0.6), large velar aperture ratio (R(v) ≈ 0.5-0.8), and rapid bell kinematics throughout development. These traits enabled it to use rowing propulsion at all stages except the very smallest sizes observed (diameter = 0.14 cm). During the juvenile stage, very rapid bell kinematics served to increase Re sufficiently for rowing propulsion. Other taxa that use rowing propulsion as adults, such as leptomedusae and scyphomedusae, typically utilize different propulsive strategies as small juveniles to function in low Re environments. We compared the performance values of the different propuls... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=4571652 Tue, 01 Feb 2011 00:00:00 +0100 4571652 http://www.medworm.com/index.php?rid=4571651&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21385953%26dopt%3DAbstract Authors: Nozawa Y, Okubo N Temporal dynamics of larval survival were examined in vitro in four broadcast-spawning reef coral species, Acropora hyacinthus, A. japonica, A. solitaryensis, and Goniastrea pectinata. Larval size was treated as an important characteristic that may relate to larval lifespan. Two patterns were observed in larval survival dynamics between the three Acropora species (mean initial larval size; 0.05-0.08 mm(3)) and G. pectinata (0.02 mm(3)), based on the timing of a sharp drop in larval survival rates (ca. > 50% reduction over a 1-2 week period). Consequently, the majority of larvae of the three Acropora species had a lifespan of less than 2-3 weeks, whereas those of G. pectinata were extended a further 2-3 weeks despite the smaller larval size. No significant ... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=4571651 Tue, 01 Feb 2011 00:00:00 +0100 4571651 http://www.medworm.com/index.php?rid=4571650&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21385954%26dopt%3DAbstract Authors: Hirose M, Obuchi M, Hirose E, Reimer JD The spawning behavior and early embryogenesis of Palythoa tuberculosa (Anthozoa, Zoantharia) were observed in August 2009 off Okinawa Island, Japan. P. tuberculosa released zygotes just after high tide around new moon nights. The mean diameter of zygotes was 365.6 ± s.d.14.8 μm, and zygotes did not contain any symbiotic algae (zooxanthellae). About 2 h after spawning, the first cleavage furrow appeared on one side of the zygotes, although it was uncertain when eggs were fertilized. After second cleavage, the arrangement of blastomeres was pseudospherical. At 9 h after spawning, the embryo became a concave-convex dish shape, then gastrulation occurred and the blastopore was formed. Seven-day old larvae were ellipsoid and about 700 μm l... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=4571650 Tue, 01 Feb 2011 00:00:00 +0100 4571650 http://www.medworm.com/index.php?rid=4571649&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21385955%26dopt%3DAbstract In this study we aimed to tease apart the relationship between fertilization success in sea urchins inside and outside of seagrass beds in St. Joseph Bay, Florida. Fluorescein dye diffusion, as a proxy for gamete diffusion, indicated higher rates of diffusion in sand habitats outside of seagrass beds. We quantified the proportion of eggs that remained on a female compared to being advected off a female over a 2-min interval in and out of grass beds. More eggs were collected inside of seagrass beds than over sand habitats, suggesting increased residence time of gametes within the beds. We induced sea urchins to spawn in experimental arrays in and out of grass beds and measured the fertilization success of eggs released from females and captured in the water column with a plankton pump. The ... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=4571649 Tue, 01 Feb 2011 00:00:00 +0100 4571649 http://www.medworm.com/index.php?rid=4571648&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21385956%26dopt%3DAbstract Authors: Ruiz-Jones GJ, Hadfield MG Larvae of the nudibranch Phestilla sibogae are induced to metamorphose by a water-borne chemical cue released by the adult nudibranch's prey, the coral Porites compressa. In competent larvae, the apical sensory organ (ASO) includes five serotonergic parampullary neurons; five ampullary neurons, the ampullae of which are filled with sensory cilia; and a basal neuropil. After sensing the coral cue, the ASO undergoes radical morphological changes: a deterioration of sensory elements in the ASO and serotonergic axons originating from them to innervate the velum. Three hours after metamorphic induction, the velar lobes are lost, the serotonergic axons begin to break apart, the five parampullary neurons begin to degenerate, and the five ampullary neurons r... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=4571648 Tue, 01 Feb 2011 00:00:00 +0100 4571648 http://www.medworm.com/index.php?rid=4571647&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21385957%26dopt%3DAbstract In this study, we investigated the effects of 17β-estradiol (a steroid) and bisphenol A (an endocrine disrupter) on the formation of sexual organs in the hermaphroditic planarian Dugesia ryukyuensis. Under control conditions, all worm tissues regenerated into sexual planarians with sexual organs within 4 weeks after ablation. However, in the presence of bisphenol A or 17β-estradiol, although they apparently regenerated into sexual planarians, the yolk glands, which are one of the female sexual organs, failed to regenerate even 7 weeks after ablation. These data suggest that planarians have a steroid hormone system, which plays a key role in the formation and maturation of sexual organs. PMID: 21385957 [PubMed - in process] (Source: The Biological Bulletin) The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=4571647 Tue, 01 Feb 2011 00:00:00 +0100 4571647 http://www.medworm.com/index.php?rid=4571646&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21385958%26dopt%3DAbstract Authors: Carpenter MA, Powell JH, Ishizuka KJ, Palmeri KJ, Rendulic S, De Tomaso AW The colonial ascidian Botryllus schlosseri undergoes a histocompatibility reaction that can result in vascular fusion of distinct genotypes, creating a chimera. Chimerism has both potential benefits, such as an immediate increase in size that may enhance growth rates, and costs. For the latter, the presence of multiple genotypes in a chimera can lead to competition between genetically distinct stem cell lineages, resulting in complete replacement of somatic and germline tissues by a single genotype. Although fusion can occur at any point after metamorphosis, previous studies have focused on chimeras created from sexually mature adults, where no benefit to chimerism has been documented. Here we focus on ... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=4571646 Tue, 01 Feb 2011 00:00:00 +0100 4571646 http://www.medworm.com/index.php?rid=4571645&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21385959%26dopt%3DAbstract Authors: Kita S, Hashiba R, Ueki S, Kimoto Y, Abe Y, Gotoda Y, Suzuki R, Uraki E, Nara N, Kanazawa A, Hatakeyama D, Kawai R, Fujito Y, Lukowiak K, Ito E In conditioned taste aversion (CTA) training performed on the pond snail Lymnaea stagnalis, a stimulus (the conditional stimulus, CS; e.g., sucrose) that elicits a feeding response is paired with an aversive stimulus (the unconditional stimulus, US) that elicits the whole-body withdrawal response and inhibits feeding. After CTA training and memory formation, the CS no longer elicits feeding. We hypothesize that one reason for this result is that after CTA training the CS now elicits a fear response. Consistent with this hypothesis, we predict the CS will cause (1) the heart to skip a beat and (2) a significant change in the heart rate.... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=4571645 Tue, 01 Feb 2011 00:00:00 +0100 4571645 http://www.medworm.com/index.php?rid=4310596&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21183440%26dopt%3DAbstract Authors: Weisz JB, Massaro AJ, Ramsby BD, Hill MS Sponges belonging to the genus Cliona are common inhabitants of many coral reefs, and as bioeroders, they play an important role in the carbonate cycle of the reef. Several Cliona species maintain intracellular populations of dinoflagellate zooxanthellae (i.e., Symbiodinium spp.), which also form symbioses with a variety of other invertebrates and protists (e.g., corals, molluscs, foraminifera). Unlike the case of coral symbioses, however, almost nothing is known of the metabolic interaction between sponges and their zooxanthella symbionts. To assess this interaction, we performed a tracer experiment to follow C and N in the system, performed a reciprocal transplant experiment, and measured the stable carbon isotope ratio of Cliona spp.... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=4310596 Wed, 01 Dec 2010 00:00:00 +0100 4310596 http://www.medworm.com/index.php?rid=4310595&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21183441%26dopt%3DAbstract Authors: Reuter KE, Levitan DR The cues triggering large-scale broadcast-spawning events in marine invertebrates are not fully understood. Using the sea urchin Lytechinus variegatus, we tested the effectiveness of a variety of potential spawning cues in eliciting a spawning response. In the laboratory, during two consecutive spawning seasons, about 400 isolated sea urchins were exposed to phytoplankton, sperm, or eggs, singly or in combination. The likelihood of spawning, time to spawning, and spawning behavior were recorded for both sexes. Sperm was most successful at inducing spawning. No response to eggs was noted. Phytoplankton alone did not trigger spawning, but when a phytoplankton cue was followed by the addition of sperm, spawning behavior was induced, the time between addition... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=4310595 Wed, 01 Dec 2010 00:00:00 +0100 4310595 http://www.medworm.com/index.php?rid=4310594&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21183442%26dopt%3DAbstract This study determined the visual spectral sensitivity of Stage I larvae and investigated whether light plays a proximate role in DVM as an exogenous cue and as an entrainment cue for an endogenous rhythm in vertical migration. Under constant conditions, larvae have a circadian rhythm (24.5-h period) in vertical swimming that resulted in a twilight DVM pattern. The behavioral response spectrum and electroretinogram recording indicated two photoreceptor spectral classes with maxima at 360 and 486 nm. When stimulated in an apparatus that simulated the underwater angular light distribution, dark-adapted larvae showed only positive phototaxis, with a threshold intensity of 1.8 × 10(13) photons m(-2) s(-1) (3.0 × 10(-5) μmoles photons m(-2) s(-1)). They have an avoidance response to predator ... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=4310594 Wed, 01 Dec 2010 00:00:00 +0100 4310594 http://www.medworm.com/index.php?rid=4310593&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21183443%26dopt%3DAbstract Authors: Bone EK, Keough MJ A colonial lifestyle necessitates communication between colony members to coordinate functions and enable resource sharing through physiological integration. Colonial integration is predicted to increase with both the size of the colony and the level of specialization (polymorphism). In modular colonies, although integration might be reflected in structural characteristics such as module spacing or branching patterns, physiological integration is fundamentally dependent on the level of connectedness between modules. In cheilostome bryozoans, funicular tissue links adjacent zooids through pores within zooid walls and is the most likely means of nutrient transport within colonies. We sought to determine whether the relative numbers of pores (septulae) and pore... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=4310593 Wed, 01 Dec 2010 00:00:00 +0100 4310593 http://www.medworm.com/index.php?rid=4310592&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21183444%26dopt%3DAbstract In this study we found that spikes vary widely in morphology, from acute spikes to flat plaques. Optical and electron microscopy has revealed that the periostraca of Laternula, Myadora, and Thraciopsis consist of an outer dense layer and an inner translucent layer. The dense layer grows at the expense of the inner layer as it progresses toward the shell edge. The spikes begin to grow in the free periostracum, within the translucent periostracal layer, immediately below the dense layer. With growth, they push the dense periostracal layer upward but without penetrating it. Those parts of the spike in contact with this layer cease to grow, which explains the typical conical shape of spikes. When fully grown, spikes reach the base of the translucent layer, becoming incorporated into the outer ... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=4310592 Wed, 01 Dec 2010 00:00:00 +0100 4310592 http://www.medworm.com/index.php?rid=4310591&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21183445%26dopt%3DAbstract We describe a new scyphozoan family, Drymonematidae, elevating the previous subfamily Drymonemidae to accommodate three species: the type species D. dalmatinum from the Mediterranean region, for which we identify a neotype; the western South Atlantic species D. gorgo; and a new species, D. larsoni from the western Atlantic and Caribbean, which also is described here. This revision emphasizes the remarkable morphological disparity of Drymonematidae from all other scyphomedusae, including allometric growth of the bell margin distal of the rhopalia, an annular zone of tentacles on the subumbrella, and ontogenetic loss of gastric filaments. Anatomical innovations are likely functionally related to predatory specialization on large gelatinous zooplankton, most notably the phylogenetically young... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=4310591 Wed, 01 Dec 2010 00:00:00 +0100 4310591 http://www.medworm.com/index.php?rid=4310590&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21183446%26dopt%3DAbstract We report the discovery of a new species of nematode that thrives in the highly acidic environment of the snottite. Micro CT scan of snottites reveals a complex interaction between the acidic snottite, nematodes, and abundant nematode-eating mites. The nematode adaptation to low pH probably protects them against mite predation, for which nematodes are most likely the most important source of carbon in this sulfur-driven ecosystem. PMID: 21183446 [PubMed - in process] (Source: The Biological Bulletin) The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=4310590 Wed, 01 Dec 2010 00:00:00 +0100 4310590 http://www.medworm.com/index.php?rid=4310589&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21183447%26dopt%3DAbstract Authors: Maliska ME, Swalla BJ PMID: 21183447 [PubMed - in process] (Source: The Biological Bulletin) The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=4310589 Wed, 01 Dec 2010 00:00:00 +0100 4310589 http://www.medworm.com/index.php?rid=4310588&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21183448%26dopt%3DAbstract Authors: Longley RD PMID: 21183448 [PubMed - in process] (Source: The Biological Bulletin) The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=4310588 Wed, 01 Dec 2010 00:00:00 +0100 4310588 http://www.medworm.com/index.php?rid=4310587&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21183449%26dopt%3DAbstract Authors: PMID: 21183449 [PubMed - in process] (Source: The Biological Bulletin) The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=4310587 Wed, 01 Dec 2010 00:00:00 +0100 4310587 http://www.medworm.com/index.php?rid=4107088&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20972253%26dopt%3DAbstract Authors: PMID: 20972253 [PubMed - in process] (Source: The Biological Bulletin) The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=4107088 Thu, 30 Sep 2010 23:00:00 +0100 4107088 http://www.medworm.com/index.php?rid=4107087&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20972254%26dopt%3DAbstract Authors: Stoneham ET, Sanders EM, Sanyal M, Dumas TC Overproduction and pruning during development is a phenomenon that can be observed in the number of organisms in a population, the number of cells in many tissue types, and even the number of synapses on individual neurons. The sculpting of synaptic connections in the brain of a developing organism is guided by its personal experience, which on a neural level translates to specific patterns of activity. Activity-dependent plasticity at glutamatergic synapses is an integral part of neuronal network formation and maturation in developing vertebrate and invertebrate brains. As development of the rodent forebrain transitions away from an over-proliferative state, synaptic plasticity undergoes modification. Late developmental changes in s... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=4107087 Thu, 30 Sep 2010 23:00:00 +0100 4107087 http://www.medworm.com/index.php?rid=4107086&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20972255%26dopt%3DAbstract Authors: Thuesen EV, Goetz FE, Haddock SH Bioluminescence in the deep-sea chaetognath Eukrohnia fowleri is reported for the first time, and behavioral, morphological, and chemical characteristics of bioluminescence in chaetognaths are examined. Until this study, the only known species of bioluminescent chaetognath was Caecosagitta macrocephala. The luminescent organ of that species is located on the ventral edge of each anterior lateral fin, whereas that of E. fowleri runs across the center of the tail fin on both dorsal and ventral sides. Scanning electron microscopy showed that the bioluminescent organs of both species consist of hexagonal chambers containing elongate ovoid particles-the organelles holding bioluminescent materials. No other luminous organism is known to use hexagonal... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=4107086 Thu, 30 Sep 2010 23:00:00 +0100 4107086 http://www.medworm.com/index.php?rid=4107085&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20972256%26dopt%3DAbstract Authors: Parrin AP, Netherton SE, Bross LS, McFadden CS, Blackstone NW Cilia-based transport systems characterize sponges and placozoans. Cilia are employed in cnidarian gastrovascular systems as well, but typically function in concert with muscular contractions. Previous reports suggest that anthozoans may be an exception to this pattern, utilizing only cilia in their gastrovascular systems. With an inverted microscope and digital image analysis, we used stoloniferan octocoral colonies growing on microscope cover glass to quantitatively describe the movement of fluids in this system for the first time. Flow in stolons (diameter ≈300 μm) is simultaneously bidirectional, with average velocities of 100-200 μm/s in each direction. Velocities are maximal immediately adjacent to the sto... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=4107085 Thu, 30 Sep 2010 23:00:00 +0100 4107085 http://www.medworm.com/index.php?rid=4107084&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20972257%26dopt%3DAbstract Authors: Thorington GU, McAuley V, Hessinger DA Studies spanning 60 years with several cnidarian species show that satiation inhibits prey capture and ingestion and that starvation increases prey capture and ingestion. Most have attributed the effects of satiation to inhibition of nematocyst discharge. We hypothesized that satiation inhibits prey capture and ingestion in sea anemones (Haliplanella luciae and Aiptasia pallida) primarily by inhibiting the intrinsic adherence (i.e., holding power) of discharging nematocysts. Using a quantitative feeding assay for H. luciae, we found that satiation completely uncoupled prey killing from prey ingestion, while nematocyst-mediated prey killing was only partially inhibited. Using A. pallida to measure nematocyst discharge and nematocyst-mediat... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=4107084 Thu, 30 Sep 2010 23:00:00 +0100 4107084 http://www.medworm.com/index.php?rid=4107083&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20972258%26dopt%3DAbstract Authors: Holland ND, Holland LZ Here we report on spawning and development of the Bahama lancelet, Asymmetron lucayanum. Ripe adults collected in Bimini spawned the same evening when placed in the dark for 90 minutes. The developmental morphology is described from whole mounts and histological sections. A comparison between development in Asymmetron and the better known cephalochordate genus Branchiostoma reveals similarities during the early embryonic stages but deviations by the late embryonic and early larval stages. Thus, the initial positions of the mouth, first gill slit, and anus differ between the two genera. Even more strikingly, Hatschek's right and left diverticula, which arise by enterocoely at the anterior end of the pharynx in Branchiostoma, never form during Asymmetron d... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=4107083 Thu, 30 Sep 2010 23:00:00 +0100 4107083 http://www.medworm.com/index.php?rid=4107082&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20972259%26dopt%3DAbstract Authors: Zhang H, Scarpa J, Hare MP Identification of mechanisms promoting prezygotic reproductive isolation and their prevalence are key goals in evolutionary biology because of their potential role in speciation. In marine broadcast-spawning species, molecular interactions between gamete surface proteins are more important than mating behavior for determining reproductive compatibility. Evidence for differential fertilization capacity has been reported from experiments utilizing competing sperm from two males sampled within populations and between species, but to our knowledge conspecific populations that might have diverged in allopatry have never been tested on the basis of sperm competition. In the present study, the gametic compatibility and embryo survivorship from matings betwe... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=4107082 Thu, 30 Sep 2010 23:00:00 +0100 4107082 http://www.medworm.com/index.php?rid=4107081&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20972260%26dopt%3DAbstract This study supports predictions central to theories of resource monopolization and sex allocation. Dissections demonstrated that unusually large males were parasitized by an undescribed species of isopod (family Entoniscidae). Infestation rates were similarly low in both sexes (≈11%-12%). The available information suggests that T. amboinensis uses pure search promiscuity as a mating system. This hypothesis needs to be formally tested with mating behavior observations and field measurements on the movement pattern of both sexes of the species. Further detailed studies on the lifestyle and sexual system of all the species within this genus and the development of a molecular phylogeny are necessary to elucidate the evolutionary history of gender expression in the genus Thor. PMID: 20972... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=4107081 Thu, 30 Sep 2010 23:00:00 +0100 4107081 http://www.medworm.com/index.php?rid=4107080&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20972261%26dopt%3DAbstract Authors: Johnson SB, Warén A, Lee RW, Kano Y, Kaim A, Davis A, Strong EE, Vrijenhoek RC Rubyspira, a new genus of deep-sea snails (Gastropoda: Abyssochrysoidea) with two living species, derives its nutrition from decomposing whalebones. Molecular phylogenetic and morphological evidence places the new genus in an exclusively deep-sea assemblage that includes several close relatives previously known as fossils associated with Cretaceous cold seeps, plesiosaur bones, and Eocene whalebones. The ability to exploit a variety of marine reducing environments may have contributed to the evolutionary longevity of this gastropod lineage. PMID: 20972261 [PubMed - in process] (Source: The Biological Bulletin) The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=4107080 Thu, 30 Sep 2010 23:00:00 +0100 4107080 http://www.medworm.com/index.php?rid=4107079&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20972262%26dopt%3DAbstract Authors: Verhoeven AB, Durham-Colleran MW, Pierson T, Boswell WT, Van Hoek ML The bacterium Francisella philomiragia has been isolated from environmental samples originating from around the globe. F. philomiragia-related strains cause francisellosis of both farmed and wild fish. In addition, occasional human infections caused by F. philomiragia are found in victims of near-drowning and patients with chronic granulomatous disease. We have shown that F. philomiragia forms in vitro biofilms with increased formation at 25 °C over 37 °C conditions. We found that F. philomiragia can form a biofilm in a co-culture with live Acanthamoeba castellanii, an aquatic amoeba. Interestingly, amoeba-conditioned supernatant has an inhibitory effect on production of biofilm by F. philomiragia, whereas ... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=4107079 Thu, 30 Sep 2010 23:00:00 +0100 4107079 http://www.medworm.com/index.php?rid=3933808&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20813983%26dopt%3DAbstract Authors: Morowitz HJ, Srinivasan V, Smith E The assumption that all biological catalysts are either proteins or ribozymes leads to an outstanding enigma of biogenesis-how to determine the synthetic pathways to the monomers for the efficient formation of catalytic macromolecules in the absence of any such macromolecules. The last 60 years have witnessed chemists developing an understanding of organocatalysis and ligand field theory, both of which give demonstrable low-molecular-weight catalysts. We assume that transition-metal-ligand complexes are likely to have occurred in the deep ocean trenches by the combination of naturally occurring oceanic metals and ligands synthesized from the emergent CO(2), H(2), NH(3), H(2)S, and H(3)PO(4). We are now in a position to investigate experimenta... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=3933808 Sat, 31 Jul 2010 23:00:00 +0100 3933808 http://www.medworm.com/index.php?rid=3933807&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20813984%26dopt%3DAbstract Authors: Reynolds KC, Watanabe H, Strong EE, Sasaki T, Uematsu K, Miyake H, Kojima S, Suzuki Y, Fujikura K, Kim S, Young CM Despite extreme differences between some shallow and deep-sea habitats, the developmental modes and larval forms of deep-sea animals are typically similar to those of their shallow-water relatives. Here we report one of the first documented exceptions to this general rule. The hydrothermal vent snail Ifremeria nautilei displays two novel life-history traits: (1) an unusual uniformly ciliated larva that we here name Warén's larva, and (2) internal brood protection in a modified metapodial pedal gland. Warén's larva emerges from the internal brood pouch as a fully ciliated lecithotrophic larva with a unique external cuticle. The larvae swim with their posterio... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=3933807 Sat, 31 Jul 2010 23:00:00 +0100 3933807 http://www.medworm.com/index.php?rid=3933806&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20813985%26dopt%3DAbstract Authors: Miguchi Y, Takata H, Doihara T, Miyawaki K, Shimokawa T, Hamada F, Kobayashi N, Matsuda S In echinoderms, the circumesophageal muscle is mesodermal in origin. Several studies of sea urchins have reported that the molecular events of myogenesis occur during the differentiation of the circumesophageal muscle in early embryogenesis. In contrast, few detailed reports have examined the differentiation of the circumesophagus muscle in larval starfish. Here, we examined the temporal-numeric distribution and differentiation of esophagus circular muscle fibers in the starfish Patiria pectinifera by using rhodamine-phalloidin staining. Muscle fibers were not detected in mouth-forming larvae, but a mean of about 10 muscle fibers was observed in 48-h larvae, and about 26 bundles were obse... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=3933806 Sat, 31 Jul 2010 23:00:00 +0100 3933806 http://www.medworm.com/index.php?rid=3933805&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20813986%26dopt%3DAbstract Authors: Maeda T, Kajita T, Maruyama T, Hirano Y Sacoglossan sea slugs retain the chloroplasts from food algae in their cells (kleptoplasty) and obtain the photosynthetic products, but the capability of kleptoplasty differs among species. One evolutionary hypothesis for kleptoplasty is that the family Volvatellidae is the ancestral sacoglossan lineage in which kleptoplasty arose, but this is based on ambiguous phylogenetic relationships. To test this hypothesis, we analyzed sacoglossan phylogeny for concatenated sequences (approximately 4000 bp) of nuclear (18S rRNA) and mitochondrial (CO1, trnV, and 16S rRNA) genes of 18 sacoglossan species, using neighbor-joining, maximum parsimony, maximum likelihood, and Bayesian methods. The resultant phylogenetic trees clearly revealed monophyly ... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=3933805 Sat, 31 Jul 2010 23:00:00 +0100 3933805 http://www.medworm.com/index.php?rid=3933804&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20813987%26dopt%3DAbstract In this study, I examined the effects of selfing throughout the life cycle of the marine bryozoan Bugula stolonifera, a colonial simultaneous hermaphrodite. In 2008, larvae from field-collected colonies were cultured through metamorphosis to reproductively mature colonies either in the presence of one other colony, the paired treatment, or alone, the solitary treatment. Results demonstrated that selfing in this species is possible, in that colonies in the solitary treatment produced viable larvae that successfully completed metamorphosis. On average, however, these colonies released significantly fewer larvae, which experienced reduced rates of metamorphic initiation and completion compared to the paired treatment. These experiments were extended in 2009, when metamorphs from colonies rear... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=3933804 Sat, 31 Jul 2010 23:00:00 +0100 3933804 http://www.medworm.com/index.php?rid=3933803&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20813988%26dopt%3DAbstract Authors: McDonald KA, Vaughn D Asexual reproduction, or cloning, of planktonic echinoderm larvae has been observed in the laboratory and in nature, but little is known about its ecology. Here we examine the effects of algal food density and of a change in food density on the incidence of cloning in larvae of the sand dollar Dendraster excentricus. Results indicate that a change in food concentration can induce cloning in plutei. Cultures transferred from a low to a high algal ration at the time when primary larvae were developing the third (posterodorsal) pair of larval arms showed decreased postoral arm length, unusual morphologies, and increased larval density in culture. These dense cultures of smaller plutei were produced within 48 h of the food pulse. The result is consistent with... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=3933803 Sat, 31 Jul 2010 23:00:00 +0100 3933803 http://www.medworm.com/index.php?rid=3933802&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20813989%26dopt%3DAbstract This study provides evidence that the suspension-feeding blue mussel, Mytilus edulis, uses biochemical cues to recognize its food. We identified lectins in mucus from the gills and labial palps, two pallial organs involved in the feeding process. These compounds were able to agglutinate rabbit and horse erythrocytes (RBC) and several species of marine microalgae representing different families. Additionally, the agglutination of RBC and microalgae was inhibited by several carbohydrates (fetuin, lipopolysaccharide (LPS), and mannose-related residues), suggesting that a suite of lectins may be present in mucus from the gills and labial palps. Results from feeding experiments, using microspheres with tailored surfaces, demonstrated that mussels preferentially ingested microspheres coated with... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=3933802 Sat, 31 Jul 2010 23:00:00 +0100 3933802 http://www.medworm.com/index.php?rid=3933801&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20813990%26dopt%3DAbstract Authors: Robbins HM, Bricelj VM, Ward JE The in vivo response of adult northern quahogs, Mercenaria mercenaria, to Aureococcus anophagefferens (brown tide) at the level of the gill was determined using video-endoscopy. Feeding activity, particle-approach velocities, and ventral-groove-transport velocities were documented after the quahogs were exposed to Isochryis galbana (baseline observations) supplemented with either toxic or nontoxic A. anophagefferens at two bloom concentrations (8 x 10(5) or 2 x 10(6) cells ml(-1)). Externally, there was no evidence of adverse effects of brown tide on feeding, as siphons remained extended and dilated. Toxic brown tide at both concentrations elicited gill muscular contractions, intermittent cessation of water flow, and decreased particle loading w... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=3933801 Sat, 31 Jul 2010 23:00:00 +0100 3933801 http://www.medworm.com/index.php?rid=3933800&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20813991%26dopt%3DAbstract Authors: Ugolini A, Borgioli G, Galanti G, Mercatelli L, Hariyama T The semi-terrestrial sandhopper Talitrus saltator uses celestial visual cues to orient along the sea-land axis of the beach. Previous spectral-filtering experiments suggested that it perceives directional information from wavelengths in the ultraviolet (UV)-blue range. Binary choice experiments between dark and UV (380-nm) light carried out on dark-adapted individuals of T. saltator showed photopositive movement to UV. Morphologically, each ommatidium in the eye consists of five retinula cells, four large and one small. In electroretinogram experiments, sensitivity of the dark-adapted eye is dominated by a receptor maximally sensitive at about 390-450 nm and secondarily sensitive at about 500-550 nm. Selective light-ad... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=3933800 Sat, 31 Jul 2010 23:00:00 +0100 3933800 http://www.medworm.com/index.php?rid=3700359&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20570845%26dopt%3DAbstract Authors: Henry JJ, Collin R, Perry KJ Recent developmental and genomic research focused on "slipper snails" in the genus Crepidula has positioned Crepidula fornicata as a de facto model system for lophotrochozoan development. Here we review recent developments, as well as earlier reports demonstrating the widespread use of this system in studies of development and life history. Recent studies have resulted in a well-resolved fate map of embryonic cell lineage, documented mechanisms for axis determination and D quadrant specification, preliminary gene expression patterns, and the successful application of loss- and gain-of-function assays. The recent development of expressed sequence tags and preliminary genomics work will promote the use of this system, particularly in the area of deve... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=3700359 Mon, 31 May 2010 23:00:00 +0100 3700359 http://www.medworm.com/index.php?rid=3700358&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20570846%26dopt%3DAbstract In this study, we compared gametogenesis, fertilization, survival, and O(2) consumption in cultured and wild colonies of A. intermedia and their offspring. Cultured A. intermedia had larger oocytes and higher fertilization and survival rates than samples from wild colonies. O(2) consumption of cultured embryos was similar to that of wild embryos. These results suggest that cultured A. intermedia and their offspring are as viable as wild colonies. Aquaria can play a role in the conservation of endangered corals, and their cultured colonies could be used to re-establish devastated species on the Okinawa reefs. PMID: 20570846 [PubMed - in process] (Source: The Biological Bulletin) The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=3700358 Mon, 31 May 2010 23:00:00 +0100 3700358 http://www.medworm.com/index.php?rid=3700357&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20570847%26dopt%3DAbstract This study investigated patterns in the relative abundance of two photosynthetic algal symbionts, zoochlorellae (ZC) and zooxanthellae (ZX), hosted by two temperate anemones, Anthopleura elegantissima and A. xanthogrammica. Previous studies have documented varying proportions of each symbiont along environmental gradients, presumably determined by their respective physiological capabilities. To test for differences in the algal type between the two host species, we sampled anemone tissues (tentacle or tentacle and body column) of similarly sized polyps that were located close together in multiple habitats: tidepools, crevices, underneath rock ledges, and along natural light gradients in caves. The ZC-A. elegantissima symbiosis was rare on the west coast of Vancouver Island, British Columbi... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=3700357 Mon, 31 May 2010 23:00:00 +0100 3700357 http://www.medworm.com/index.php?rid=3700356&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20570848%26dopt%3DAbstract Authors: Cerda O, Hinojosa IA, Thiel M Many small arthropod herbivores from terrestrial and marine environments construct tubicolous nest-like domiciles on their host plants or algae by rolling up selected portions of the leaf or blade. Nests serve as both shelter and food, which results in conflicting needs for the grazers because feeding activity continuously destroys parts of the nests. While the nesting habit of ampithoid amphipods and other peracarid crustaceans is widely known, very little is known about the nest dynamics and how the conflict between shelter and food requirements is resolved. Herein we examined the nest-building behavior and nest occupancy of the kelp-dwelling amphipod Peramphithoe femorata on the giant kelp Macrocystis pyrifera. Domiciles on the distal-most part... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=3700356 Mon, 31 May 2010 23:00:00 +0100 3700356 http://www.medworm.com/index.php?rid=3700355&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20570849%26dopt%3DAbstract Authors: Yusa Y, Takemura M, Miyazaki K, Watanabe T, Yamato S In the lepadomorph barnacle Octolasmis warwickii, individuals are often found attached to the scutum of conspecifics living externally on the crab hosts. To test whether these conspecific-attached individuals are dwarf males, as are known to occur in other suborders of barnacles, we compared the pattern of attachment, size-frequency distribution, and reproductive status of the conspecific-attached (Con-A) and crab-attached (Crab-A) individuals. Con-As were smaller than Crab-As. There was a positive relationship between the body size of Crab-As and the number of individuals on them. Con-As had longer penises than Crab-As of the same body size, and their testes were better developed. The four largest Con-As examined were brood... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=3700355 Mon, 31 May 2010 23:00:00 +0100 3700355 http://www.medworm.com/index.php?rid=3700354&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20570850%26dopt%3DAbstract In this study prezygotic and postzygotic components of reproductive incompatibility were examined in laboratory crosses. Conspecific crosses showed significantly greater rates of fertilization than heterospecific crosses, although some females of both species showed heterospecific gamete compatibility. The proportion of fertilized eggs developing into normal larvae was not significantly different between conspecific and heterospecific crosses, but survival of normal larvae was greater for conspecific crosses. Mixed-species sperm experiments suggested that conspecific sperm preference may further limit hybridization. The different components of reproductive incompatibility and total incompatibility varied among females of both species. Although our study has shown that partial reproductive ... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=3700354 Mon, 31 May 2010 23:00:00 +0100 3700354 http://www.medworm.com/index.php?rid=3700353&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20570851%26dopt%3DAbstract Authors: Nusnbaum M, Derby CD Sea hares, Aplysia californica, have a diversity of anti-predatory defenses. One is an actively released chemical defense: an ink secretion that is a mixture of two glandular products--ink from the ink gland and opaline from the opaline gland. The mechanisms of action of ink secretion and its components have recently been examined in detail against several predatory invertebrates. Our goal is to extend this mechanistic analysis to predatory vertebrates. Toward this end, the current study details the effects of ink, opaline, and one set of its components--the products of the reaction of escapin, an l-amino acid oxidase, with its natural substrates, L-lysine and L-arginine--on the palatability of food for five species of fishes: bluehead wrasses Thalassoma b... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=3700353 Mon, 31 May 2010 23:00:00 +0100 3700353 http://www.medworm.com/index.php?rid=3700352&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20570852%26dopt%3DAbstract Authors: Suljak SW, Rose CM, Sabatier C, Le T, Trieu Q, Verley DR, Lewis AM, Birmingham JT Gamma-aminobutyric acid (GABA) is best known as an inhibitory neurotransmitter in the mammalian central nervous system. Here we show, however, that GABA has an excitatory effect on nerve-evoked contractions and on excitatory junctional potentials (EJPs) of the gastric mill 4 (gm4) muscle from the stomach of the crab Cancer borealis. The threshold concentration for these effects was between 1 and 10 micromol l(-1). Using immunohistochemical techniques, we found that GABA is colocalized with the vesicle-associated protein synapsin in nearby nerves and hence is presumably released there. However, since these nerves do not innervate the muscle directly, we conclude that these release sites are not th... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=3700352 Mon, 31 May 2010 23:00:00 +0100 3700352 http://www.medworm.com/index.php?rid=3700351&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20570853%26dopt%3DAbstract Authors: Frolova LT, Dolmatov IY The morphology and regeneration of the digestive system of the ophiuroid Amphipholis kochii were investigated. The epithelia of the esophagus and stomach of A. kochii were composed of typical enterocytes and mucous cells. The digestive epithelium of the stomach contained two types of granular secretory cells. After autotomy of the disk, the animals retained the esophagus and a small part of the stomach. The dedifferentiation of enterocytes and mucous cells began on the first day after autotomy. On day 3 the cells formed an anlage of stomach around the mouth opening. Later, the stomach anlage grew as a result of cell proliferation. The opening on the aboral side of the body was closed by day 7. By this time differentiating cells were already observed in ... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=3700351 Mon, 31 May 2010 23:00:00 +0100 3700351 http://www.medworm.com/index.php?rid=3339944&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20203248%26dopt%3DAbstract In this study we investigate the distribution of ChEs and their kinetic properties in diverse tissues of the common prawn Palaemon serratus. The results concerning the histochemical localization of ChEs suggest that the highest amount of ChE activity occurs in prawn eyes, followed by the brain, gills, and digestive tract. Negligible staining was observed in the muscle. We describe the kinetic properties of ChEs in eyes, gills, and hepatopancreas, investigating their substrate preferences with different thiocholine esters and their sensitivity to inhibition with selective inhibitors. The results suggest that the studied enzymes are ChEs and not nonspecific esterases, due to their apparent affinity for choline esters, with a distinct preference for the substrate acetylthiocholine, and their ... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=3339944 Mon, 01 Feb 2010 00:00:00 +0100 3339944 http://www.medworm.com/index.php?rid=3339943&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20203249%26dopt%3DAbstract Authors: Miyamae Y, Komuro M, Murata A, Aono K, Nishikata K, Kanazawa A, Fujito Y, Komatsu T, Ito D, Abe T, Nagayama M, Uchida T, Gohara K, Murakami J, Kawai R, Hatakeyama D, Lukowiak K, Ito E The pond snail Lymnaea stagnalis moves along the sides and bottom of an aquarium, but it can also glide upside down on its back below the water's surface. We have termed these two forms of locomotion "standard locomotion" and "upside-down gliding," respectively. Previous studies showed that standard locomotion is produced by both cilia activity on the foot and peristaltic contraction of the foot muscles, whereas upside-down gliding is mainly caused by cilia activity. The pedal A neurons are thought to receive excitatory octopaminergic input, which ultimately results in increased cilia beating. Ho... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=3339943 Mon, 01 Feb 2010 00:00:00 +0100 3339943 http://www.medworm.com/index.php?rid=3339942&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20203250%26dopt%3DAbstract A "Mimic Octopus" in the Atlantic: Flatfish Mimicry and Camouflage by Macrotritopus defilippi. Biol Bull. 2010 Feb;218(1):15-24 Authors: Hanlon RT, Watson AC, Barbosa A The sand-dwelling octopus Macrotritopus defilippi was filmed or photographed in five Caribbean locations mimicking the swimming behavior (posture, style, speed, duration) and coloration of the common, sand-dwelling flounder Bothus lunatus. Each species was exceptionally well camouflaged when stationary, and details of camouflaging techniques are described for M. defilippi. Octopuses implemented flounder mimicry only during swimming, when their movement would give away camouflage in this open sandy habitat. Thus, both camouflage and fish mimicry were used by the octopuses as a primary defense against visual preda... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=3339942 Mon, 01 Feb 2010 00:00:00 +0100 3339942 http://www.medworm.com/index.php?rid=3339941&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20203251%26dopt%3DAbstract Authors: Wier AM, Sacchi L, Dolan MF, Bandi C, Macallister J, Margulis L The fine structure of spirochete attachments to the plasma membrane of anaerobic protists displays variations here interpreted as legacies of an evolutionary sequence analogous to that from free-living spirochetes to undulipodia (eukaryotic "flagella" and homologous structures). Attached spirochetes form a vestment, a wriggling fringe of motile cells at the edge of the plasma membrane of unidentified cellulolytic protist cells in the hypertrophied hindgut of the digestive system of Mastotermes darwiniensis, the large wood-feeding termite from northern Australia. From the membrane extend both undulipodia and a complex of comparably sized (10-12 mum x 0.2-0.3 mum) ectosymbiotic spirochetes that resembles unruly cili... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=3339941 Mon, 01 Feb 2010 00:00:00 +0100 3339941 http://www.medworm.com/index.php?rid=3339940&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20203252%26dopt%3DAbstract In conclusion, 17beta-estradiol and progesterone influence VTG synthesis, although our data indicate that they act through different pathways and are not effective until the proper hormonal environment is established, as demonstrated by their inefficacy in NV females. PMID: 20203252 [PubMed - in process] (Source: The Biological Bulletin) The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=3339940 Mon, 01 Feb 2010 00:00:00 +0100 3339940 http://www.medworm.com/index.php?rid=3339939&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20203253%26dopt%3DAbstract Authors: Pace DA, Maxson R, Manahan DT Previous research has shown that developing stages of the Antarctic sea urchin Sterechinus neumayeri have high rates of protein synthesis that are comparable to those of similar species living in much warmer waters. Direct measurements of the biosynthetic capacities of isolated ribosomes have not been reported for marine organisms living in the extreme-cold environment of Antarctica. Such measurements are required for a mechanistic understanding of how the critical and highly complex processes involved in protein synthesis are regulated in animals living in the coldest marine environment on Earth (< -1 degrees C). We tested the hypothesis that high rates of protein synthesis in the cold are a direct result of high biosynthetic capacities of rib... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=3339939 Mon, 01 Feb 2010 00:00:00 +0100 3339939 http://www.medworm.com/index.php?rid=3339938&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20203254%26dopt%3DAbstract The objective of this study is to identify surface carbohydrates on zebra mussel, Dreissena polymorpha, eggs and sperm and to analyze their potential role in fertilization. The lectins WGA, Con A, LcH, LTA, SBA, PNA, and GSII were tested for affinity to both eggs and sperm. WGA, Con A, and LcH uniformly labeled eggs. LTA, SBA, PNA, and GSII did not. WGA labeled the entire sperm surface including the unreacted acrosome. Labeling by Con A, LcH, LTA, SBA, PNA, and GSII was restricted to the inner acrosomal region of acrosome-reacted sperm. GSII labeling suggests the presence of N-acetyl-d-glucosamine (GlcNAc) only in the inner acrosomal membrane and not on eggs. GlcNAc blocked sperm-egg binding. GSII labeling was associated with a ring-like structure at the site of sperm entry intimately asso... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=3339938 Mon, 01 Feb 2010 00:00:00 +0100 3339938 http://www.medworm.com/index.php?rid=3339937&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20203255%26dopt%3DAbstract In this study, we used lectins tagged with fluorescein isothiocyanate (FITC) to characterize carbohydrate moieties on the surface of microalgal species and evaluate the effect of oyster mucus on lectin binding. These analyses revealed that concanavalin A (Con A), one of six lectins tested, bound to Isochrysis sp., while Nitzschia closterium reacted with Pisum sativum agglutinin (PNA) and peanut agglutinin (PEA). The cell surface of Rhodomonas salina bound with PNA and Con A, and Tetraselmis maculata cell surface was characterized by binding with PNA, PEA, and Con A. Pre-incubation of microalgae with oyster pallial mucus significantly decreased the binding of FITC-labeled lectins, revealing that lectins present in mucus competitively blocked binding sites. This decrease was reversed by wash... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=3339937 Mon, 01 Feb 2010 00:00:00 +0100 3339937 http://www.medworm.com/index.php?rid=3339936&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20203256%26dopt%3DAbstract Authors: Dong YW, Ji TT, Meng XL, Dong SL, Sun WM We studied thermal tolerance limits, heat-hardening, and Hsp70 to elucidate the difference in thermotolerance between two color variants of the sea cucumber Apostichopus japonicus. Green and Red variants occupy different habitats and have different aestivation responses to high temperature in summer. In the absence of heat-hardening, the variants showed no difference in the temperature at which 50% of the individuals died: Green, 31.49 degrees C; Red, 31.39 degrees C. However, Green specimens acquired higher thermotolerance than Red after a prior sublethal heat exposure. After 72 h of recovery from a heat-hardening treatment (30 degrees C for 2 h), the survival of Green variants was more than 50% and that of Red was less than 5% when th... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=3339936 Mon, 01 Feb 2010 00:00:00 +0100 3339936 http://www.medworm.com/index.php?rid=3339935&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20203257%26dopt%3DAbstract In this study, phylogenetic analysis was carried out on 16S rRNA sequences obtained from echinoderm-associated bacteria, resulting in the identification of four species of putative SCB. All four bacteria were identified from the holothurian Stichopus mollis, and two of the four were also found in the asteroid Patiriella sp. Two of these bacteria belong to the Alphaproteobacteria, and two to the Gammaproteobacteria. In addition to phylogenetic analysis, fluorescence in situ hybridization (FISH) assays were carried out on Patiriella sp., S. mollis, and the asteroid Astrostole scabra. Results showed that Patiriella sp. and S. mollis contain SCB, in agreement with the phylogenetic analysis, while SCB were not detected in A. scabra. Of the bacteria detected using FISH, more than 80% were recogn... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=3339935 Mon, 01 Feb 2010 00:00:00 +0100 3339935 http://www.medworm.com/index.php?rid=3135756&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20040746%26dopt%3DAbstract Authors: Kitazawa C, Nishimura H, Yamaguchi T, Nakano M, Yamanaka A We have re-observed in detail the development of the sea urchin species Temnopleurus toreumaticus, which is considered to be a typical indirect-developing species with a feeding larval stage. In this re-observation, we discovered two new morphological traits in the early embryonic stages of T. toreumaticus. The first trait is that, immediately after fertilization, the egg enters a stage in which wrinkles form on its surface as a result of actin polymerization. The second new trait is that the blastulae form wrinkles; in sea urchins, this has previously been known only in direct-developing species that have a nonfeeding larval stage and form wrinkles during the blastula stage, before hatching. These phenomena indicate t... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=3135756 Tue, 01 Dec 2009 00:00:00 +0100 3135756 http://www.medworm.com/index.php?rid=3135755&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20040747%26dopt%3DAbstract Authors: Srinivasan V, Morowitz HJ All extant life forms depend, directly or indirectly, on the autotrophic fixation of the dominant elements of the biosphere: carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur. We have earlier presented the canonical network of reactions that constitute the anabolism of a reductive chemoautotroph. Separating this network into subgraphs reveals several empirical generalizations: (1) acetate (acetyl-CoA), pyruvate, phosphoenol pyruvate, oxaloacetate, and 2-oxoglutarate serve as universal starting points for all pathways leading to the universal building blocks-20 amino acids and 4 ribonucleotide triphosphates; (2) all pathways are anabolic; (3) all reactions operate by complete utilization of outputs with no molecules left behind as waste, ensur... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=3135755 Tue, 01 Dec 2009 00:00:00 +0100 3135755 http://www.medworm.com/index.php?rid=3135754&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20040748%26dopt%3DAbstract Authors: Taris N, Boudry P, Bonhomme F, Camara MD, Lapègue S Marine species with high fecundity and high early mortality may also have high variance in reproductive success among individuals due to stochastic factors, making successful reproduction a "sweepstakes." In some cases, the impact is sufficient to reduce the effective number of breeders in wild populations. We tested two predictions of the sweepstakes reproductive success hypothesis in a French Atlantic population of the European flat oyster, Ostrea edulis, by evaluating (1) whether individuals belonging to temporally discrete recruitment cohorts within a single reproductive season displayed reduced genetic variation relative to the entire adult population, and (2) whether these temporal cohorts of recruits were genetica... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=3135754 Tue, 01 Dec 2009 00:00:00 +0100 3135754 http://www.medworm.com/index.php?rid=3135753&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20040749%26dopt%3DAbstract We examined sublethal predation in the polychaete Diopatra cuprea, an important ecosystem engineer of intertidal and shallow subtidal marine sediments in the western Atlantic. D. cuprea commonly loses its antennae and portions of its anterior to predator attacks; these lost body portions are subsequently regenerated. We asked (i) if the intensity of sublethal predation differs for D. cuprea populations in Virginia versus Florida, (ii) if sublethal predation varies temporally in each region, and (iii) if sublethal predation influences activity and tube-building rates. Within Florida, we also drew comparisons between D. cuprea and the closely related onuphid Americonuphis magna. Surprisingly, we found that sublethal predation is more intense in Virginia than in Florida, likely making substan... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=3135753 Tue, 01 Dec 2009 00:00:00 +0100 3135753 http://www.medworm.com/index.php?rid=3135752&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20040750%26dopt%3DAbstract This study is the first detailed account of early embryology for any member of the Oweniidae. Light, confocal, and scanning electron microscopy were used to investigate organogenesis from fertilization through metamorphosis in Owenia collaris. Equal spiral cleavage yields an embryo with an unusually large blastocoel for a spiralian. The embryo undergoes gastrulation by invagination, and begins swimming 24 h after fertilization. Three important events deviate markedly from stereotypical polychaete embryogenesis. First, at the 8-cell stage the micromeres are larger than the macromeres, as in nemerteans. Second, the blastopore becomes the anus, as in some deuterostomes, while the stomodeum may form secondarily. Third, the cells that would form the prototroch in a canonical spiralian trochopho... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=3135752 Tue, 01 Dec 2009 00:00:00 +0100 3135752 http://www.medworm.com/index.php?rid=3135751&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20040751%26dopt%3DAbstract Authors: Randall CJ, Szmant AM Elevated seawater temperatures during the late summer have the potential to negatively affect the development and survivorship of the larvae of reef corals that are reproductive during that time of year. Acropora palmata, a major Caribbean hermatype, reproduces annually during August and September. A. palmata populations have severely declined over the past three decades, and recovery will require high recruitment rates. Such recruitment will be limited if larval supply is reduced by elevated temperatures. The effects of elevated temperatures on development, survival, and larval settlement of A. palmata were investigated by culturing newly fertilized eggs at temperatures ranging from 27.5 to 31.5 degrees C. Development was accelerated and the percentage o... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=3135751 Tue, 01 Dec 2009 00:00:00 +0100 3135751 http://www.medworm.com/index.php?rid=3135750&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20040752%26dopt%3DAbstract Authors: Feitl KE, Millett AF, Colin SP, Dabiri JO, Costello JH Scyphomedusae undergo a predictable ontogenetic transition from a conserved, universal larval form to a diverse array of adult morphologies. This transition entails a change in bell morphology from a highly discontinuous ephyral form, with deep clefts separating eight discrete lappets, to a continuous solid umbrella-like adult form. We used a combination of kinematic, modeling, and flow visualization techniques to examine the function of the medusan bell throughout the developmental changes of the scyphomedusa Aurelia aurita. We found that flow around swimming ephyrae and their lappets was relatively viscous (1 < Re < 10) and, as a result, ephyral lappets were surrounded by thick, overlapping boundary layers that occ... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=3135750 Tue, 01 Dec 2009 00:00:00 +0100 3135750 http://www.medworm.com/index.php?rid=3135749&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20040753%26dopt%3DAbstract Authors: Duda TF, Kohn AJ, Matheny AM Anomalous mitochondrial and nuclear gene sequences in individuals of the widely distributed tropical marine gastropod Conus ebraeus that were not distinguishable by shell shape and color pattern characters suggested the presence of a second, cryptic species. We tested this hypothesis by genetic, morphological, and ecological comparisons of additional individuals from the site in Okinawa where the two forms co-occurred. Radular tooth size and shape, prey type in nature, and microhabitats utilized differed markedly between the two forms. Adults with typical C. ebraeus DNA and radular teeth preyed primarily on errant polychaetes (Eunicidae); those with anomalous DNA and teeth ate mainly sedentary capitellids. Juveniles (shell length <13 mm) had mor... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=3135749 Tue, 01 Dec 2009 00:00:00 +0100 3135749 http://www.medworm.com/index.php?rid=3135748&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20040754%26dopt%3DAbstract Authors: Eno CC, Böttger SA, Walker CW The purple sea urchin, Strongylocentrotus purpuratus, is the only non-chordate deuterostome model with a fully sequenced genome. Chromosomal localization of individual genes and resulting gene maps are unavailable for this or for any sea urchin. As a result, the purple sea urchin genome has not been mapped onto specific chromosomes and remains inaccessible to genome-wide approaches addressing questions that require positional information for particular genes. Here we describe the first successful methods for karyotyping and localizing specific gene loci on chromosomes of Strongylocentrotus purpuratus and those of the phylogenetically related Strongylocentrotus droebachiensis. Both species have 42 chromosomes in their diploid genomes (n = 21).... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=3135748 Tue, 01 Dec 2009 00:00:00 +0100 3135748 http://www.medworm.com/index.php?rid=3135747&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20040755%26dopt%3DAbstract Authors: Vázquez-Acevedo N, Rivera NM, Torres-González AM, Rullan-Matheu Y, Ruíz-Rodríguez EA, Sosa MA The freshwater prawn Macrobrachium rosenbergii is a tropical crustacean with characteristics similar to those of lobsters and crayfish. Adult males develop through three morphological types-small (SC), yellow (YC), and blue claws (BC)-with each representing a level in the dominance hierarchy of a group, BC males being the most dominant. We are interested in understanding the role played by neuropeptides in the mechanisms underlying aggressive behavior and the establishment of dominance hierarchies in this type of prawn. SIFamides are a family of arthropod peptides recently identified in the central nervous system of insects and crustaceans, where it has been linked... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=3135747 Tue, 01 Dec 2009 00:00:00 +0100 3135747 http://www.medworm.com/index.php?rid=2947850&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19875816%26dopt%3DAbstract This study tested the hypothesis that cloning in D. excentricus plutei is maternally influenced. Plutei from three half-sibling larval families (different mothers, same father) were exposed to fish mucus for 9 days during early development. Cloning was inferred in a percentage of plutei from each family; however, the rate and success of cloning differed significantly among the larval half-siblings. Unexpectedly, all mucus-treated plutei were smaller and developmentally delayed when compared to all plutei reared in the absence of a mucus stimulus. Thus, while the results from this study support the hypothesis of an influence of mothers on cloning of larval offspring, reduced larval size was a uniform response to fish mucus and did not indicate an effect of mothers. Hypotheses of the develop... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=2947850 Thu, 01 Oct 2009 00:00:00 +0100 2947850 http://www.medworm.com/index.php?rid=2947849&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19875817%26dopt%3DAbstract We examined the impact of macroscopic benthic structure on the maximum flow speeds and the corresponding macroalgal community cover and morphological diversity observed in response to microhabitats in both exposed and sheltered near-shore sites. Flow speeds were reduced by a factor of 2 within crevices and also in the flow-shadow of protruding rock substrate when compared to neighboring unobstructed planar microhabitats. Algal communities within crevices and in the wake of protrusions were found to have greater cover of foliose red algal species compared to horizontal microhabitats in exposed sites, but reduced cover of these species in sheltered sites. The morphologies of two rhodophytes common to all microhabitats, Chondracanthus spinosus and Pterocladiella capillacea, were examined at b... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=2947849 Thu, 01 Oct 2009 00:00:00 +0100 2947849 http://www.medworm.com/index.php?rid=2947848&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19875818%26dopt%3DAbstract This study confirms the presence of lectins in mucus that covers the feeding organs of oysters and suggests a new concept with regard to particle processing by suspension-feeding bivalves: specific interactions between carbohydrates on the surface of particles and lectins within the mucus mediate the selection and rejection processes. PMID: 19875818 [PubMed - in process] (Source: The Biological Bulletin) The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=2947848 Thu, 01 Oct 2009 00:00:00 +0100 2947848 http://www.medworm.com/index.php?rid=2947847&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19875819%26dopt%3DAbstract Authors: Matsumoto T, Ihara H, Ishida Y, Okada T, Kurata M, Sawada Y, Ishibashi Y We used electroretinogram recordings to investigate visual function in the dark-adapted eyes of the juvenile scombrid fishes Pacific bluefin tuna (Thunnus orientalis) and chub mackerel (Scomber japonicus) and the carangid fish striped jack (Pseudocaranx dentex). Despite the fast swimming speed of the Pacific bluefin tuna, analysis of flicker electroretinograms showed that visual temporal resolution in this species was inferior to that in chub mackerel. Peak wavelengths of spectral sensitivity in Pacific bluefin tuna and striped jack were 479 and 512 nm, respectively. The light sensitivity of Pacific bluefin tuna was comparable to that of chub mackerel but lower than that of striped jack. The Pacific bluef... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=2947847 Thu, 01 Oct 2009 00:00:00 +0100 2947847 http://www.medworm.com/index.php?rid=2947846&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19875820%26dopt%3DAbstract Authors: Kaji T, Shimizu K, Artinger KB, Yasui K The oral apparatus in lancelets undergoes a remarkable modification during larval development, especially during metamorphosis, when the oral innervation is radically altered. The larval mouth opens on the left side at the early larval stage, and a peripheral nerve network, the oral nerve ring (ONR), develops around it. The ONR enlarges as the mouth expands caudally, eventually receiving fibers from nerves as far back as the tenth on the left side. The mouth shrinks during metamorphosis, and with this change the ONR regresses; the posterior sixth to tenth nerves become freed from the connection with the ONR, whereas the fourth and fifth nerves retain their connections. This modification is the basis for the asymmetric innervation to the ... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=2947846 Thu, 01 Oct 2009 00:00:00 +0100 2947846 http://www.medworm.com/index.php?rid=2947845&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19875821%26dopt%3DAbstract Authors: Bell GW, Eggleston DB, Noga EJ Generalizing the impacts of hypoxia on aquatic animal populations is difficult due to differences in behavioral and physiological responses among individuals as well as varying hydrodynamics of hypoxic events. Information on which environmental cues animals use to avoid hypoxia and how abiotic covariates and physiology influence avoidance behavior is lacking. Our laboratory flume studies quantified the interacting effects of hydrography (dissolved oxygen [DO], temperature, and salinity), hydrodynamics (rate of DO decline and current speed), and physiological state on avoidance behaviors of blue crabs (Callinectes sapidus). Changes in DO stimulated increased rates of movement, regardless of whether the change resulted in hypoxia. Increased rates o... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=2947845 Thu, 01 Oct 2009 00:00:00 +0100 2947845 http://www.medworm.com/index.php?rid=2947844&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19875822%26dopt%3DAbstract Authors: Cannuel R, Beninger PG, McCombie H, Boudry P Study of gill development in bivalve larvae and postlarvae provides information on the evolution of this organ and feeding mechanisms of early stages. Scanning electron microscopy was used to document the development of the filibranch homorhabdic gill in hatchery-reared larval, postlarval, and juvenile Mytilus edulis. Four key stages were identified during gill development: (1) transfer of the particle collection function from velum to gill at metamorphosis, with subsequent elongation of the gill filaments to form a gill basket, with complete frontal ciliation; (2) reflection of the inner demibranchs, and transition to a V-shaped gill; (3) delayed development of the outer demibranchs, occuring simultaneously along the gill axis, wit... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=2947844 Thu, 01 Oct 2009 00:00:00 +0100 2947844 http://www.medworm.com/index.php?rid=2947843&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19875823%26dopt%3DAbstract We report the expression of Hunchback (Hb)-like protein during embryonic and larval development in two caenogastropods, Crepidula fornicata and Ilyanassa obsoleta. During the cleavage stages of these species, Hb-like protein is uniformly expressed in micromere and macromere nuclei. At gastrulation, gastropod Hb-like protein is expressed in the surface epithelium that undergoes epiboly. During organogenesis, gastropod Hb-like protein is expressed in the developing ciliated structures associated with feeding and locomotion. We find no detectable gradient or regionalization of Hb-like protein in gastropod embryos or larvae that resembles the graded Hb pattern of expression observed in dipteran insect embryos. Rather we found that the spatiotemporal expression profile of gastropod Hb-like prot... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=2947843 Thu, 01 Oct 2009 00:00:00 +0100 2947843 http://www.medworm.com/index.php?rid=2947842&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19875824%26dopt%3DAbstract Authors: Cataldi A, Di Giacomo V, Rapino M, Zara S, Rana RA Although ionizing radiation induces a loss of proliferative capacity as well as cell death by apoptosis and necrosis, cells can oppose the damaging effects by activating survival signal pathways. Here we report the effect of 1.5- and 6-Gy doses of ionizing radiation on apoptotic protein kinase Cdelta (PKCdelta) and survival cyclic-nucleotide response element-binding protein (CREB) signal in Jurkat T cells. Cell cycle analysis, performed by flow cytometry, showed a significant G2M arrest 24 h after exposure to 6 Gy. This arrest was accompanied by dead cells, which increased in number up to 7 days, when cell viability was further reduced. The response was apparently promoted by caspase-3-mediated PKCdelta activation, and thus ap... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=2947842 Thu, 01 Oct 2009 00:00:00 +0100 2947842 http://www.medworm.com/index.php?rid=2702985&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19679717%26dopt%3DAbstract Authors: Olds JL PMID: 19679717 [PubMed - in process] (Source: The Biological Bulletin) The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=2702985 Fri, 31 Jul 2009 23:00:00 +0100 2702985 http://www.medworm.com/index.php?rid=2702984&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19679718%26dopt%3DAbstract Authors: Neves RC, Sørensen KJ, Kristensen RM, Wanninger A Complexity of metazoan bodyplans is commonly assumed to be correlated to the absolute number of cells and the number of cell types present in a species (1). Sexually mature individuals of the smallest free-living animals have a minimum of several hundred somatic cells, and only secondarily simplified parasitic or commensal species range below this threshold. Males of the two hitherto described representatives of the phylum Cycliophora (2), with a body length of about 40 mum, are among the smallest existing free-living metazoans, yet they exhibit an amazingly complex bodyplan. Herein, we show that only a few dozen cells account for this complexity. We conclude therefore that metazoan complexity is not obligatorily correlate... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=2702984 Fri, 31 Jul 2009 23:00:00 +0100 2702984 http://www.medworm.com/index.php?rid=2702983&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19679719%26dopt%3DAbstract Authors: Meyer E, Manahan DT Transport of amino acids from low concentrations in seawater by marine invertebrates has been extensively studied, but few of the genes involved in this physiological process have been identified. We have characterized three amino acid transporter genes cloned from embryos of the sea urchin Strongylocentrotus purpuratus. These genes show phylogenetic proximity to classical amino acid transport systems, including Gly and B0+, and the inebriated gene (INE). Heterologous expression of these genes in frog oocytes induced a 40-fold increase in alanine transport above endogenous levels, demonstrating that these genes mediate alanine transport. Antibodies specific to one of these genes (Sp-AT1) inhibited alanine transport, confirming the physiological activity of ... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=2702983 Fri, 31 Jul 2009 23:00:00 +0100 2702983 http://www.medworm.com/index.php?rid=2702982&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19679720%26dopt%3DAbstract Authors: Reft AJ, Westfall JA, Fautin DG Using scanning and transmission electron microscopy, we studied formation of the structure at the apical end of sea anemone nematocysts through which the tubule everts at discharge. In anemones of the genus Metridium, we found that each of the three solid triangular apical flaps comprises two layers that are continuous with those of the capsule wall: the electron-lucent inner layer is bound to the electron-dense outer layer. The two-layer structure is obvious in some discharged capsules in which, perhaps due to fixation, the layers part at the flap's periphery. Before the nematocyst discharges, a channel leads from a pore at the tip of the joined flaps into the lumen of the inverted tubule. The thin laminate layer that coats each flap lines the ... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=2702982 Fri, 31 Jul 2009 23:00:00 +0100 2702982 http://www.medworm.com/index.php?rid=2702981&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19679721%26dopt%3DAbstract Authors: Gray GC, Martin VJ, Satterlie RA Cubomedusae (box jellyfish) are well known for strong directional swimming, rapid responses to visual stimuli, and complex lensed eyes comparable to those of more advanced multicellular animals. They possess a total of 24 eyes that are of four morphologically different types, yet little is known about the neural organization of their eyes. The eyes are located on ganglion-like structures called rhopalia. Each of the four rhopalia contains an upper and a lower lensed eye (with a cornea, lens, and retina), two pit ocelli, and two slit ocelli. Transmission electron microscopy was used to examine the synaptic morphology of the eyes and pacemaker region of four species of cubozoans (Tamoya haplonema, Carybdea marsupialis, Tripedalia cystophora, and ... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=2702981 Fri, 31 Jul 2009 23:00:00 +0100 2702981 http://www.medworm.com/index.php?rid=2702980&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19679722%26dopt%3DAbstract Authors: Musolf BE, Spitzer N, Antonsen BL, Edwards DH The crayfish hindgut is a morphologically differentiated tube that varies along its length in the distribution of muscles and glands, contractile properties, serotonergic innervation, patterns of 5-HT receptor expression, and sensitivity to serotonin (5-HT). Anatomical differences divide the hindgut into five distinct segments along its length. Spontaneous pulsatile contractions produced by the isolated hindgut decrease in force and increase in frequency along the anterior-posterior axis. Central input to the hindgut comes from a large cluster of 5-HT-immunoreactive neurons in the terminal abdominal ganglion that form a large nerve plexus on the hindgut. 5-HT(1alpha) and 5-HT(2beta) receptors vary in their distribution along the hi... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=2702980 Fri, 31 Jul 2009 23:00:00 +0100 2702980 http://www.medworm.com/index.php?rid=2702979&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19679723%26dopt%3DAbstract Authors: Russell J, Phillips N We used field surveys and multi-factorial experiments to examine synergistic effects of ultraviolet radiation (UVR) and low tide conditions on the embryonic mortality of two bubble-shell snail species that deposit gelatinous egg masses in intertidal mudflats: Haminoea zelandiae from New Zealand, and Haminoea vesicula from Washington, USA. Egg masses of both species were predominantly found in shallow pools at low tide, and a substantial proportion of both were found in sunny as well as shaded microhabitats. Both exposure to sun and desiccation led to increased embryonic mortality for naturally deposited egg masses of H. zelandiae compared to those that were shaded or submerged. For H. vesicula, although mortality was double for embryos within desiccated e... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=2702979 Fri, 31 Jul 2009 23:00:00 +0100 2702979 http://www.medworm.com/index.php?rid=2702978&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19679724%26dopt%3DAbstract In this study we determined the upper lethal thermal limits, for both air and water, of the blue mussel Mytilus edulis via laboratory experiments. Tolerances vary seasonally, with a difference between media of 0.7 degrees C in June and 4.8 degrees C in November, as well as a decrease with multiple exposures. Measured lethal limits were then compared to field measurements of environmental temperature and concurrent measurements of mortality rates. Field results indicate that mortality in the intertidal occurs at rates expected from laboratory responses to elevated temperature. Hindcasts, retrospective analyses of historical data, indicate that high rates of mortality have shifted 51 and 42 days earlier in Beaufort, North Carolina, and Oregon Inlet, North Carolina, respectively, between 1956... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=2702978 Fri, 31 Jul 2009 23:00:00 +0100 2702978 http://www.medworm.com/index.php?rid=2702977&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19679725%26dopt%3DAbstract We examined fine-scale patterns of genetic differentiation among populations in the ampharetid polychaete Hobsonia florida in Long Island Sound (LIS) relative to its life-history traits and the geologic history of the region. Mitochondrial DNA sequencing of cytochrome oxidase I (COI) revealed 15 unique haplotypes among four populations in LIS and two outgroups. Populations in LIS exhibited the greatest haplotypic diversity compared to outgroup populations. Analysis of molecular variance revealed a highly significant level of genetic heterogeneity (P < 0.001) in LIS, with almost 40% of the variance attributed to differences among populations. Population differentiation was further revealed by highly significant fixation indices for all pairwise comparisons. Analysis using a mtDNA COI mol... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=2702977 Fri, 31 Jul 2009 23:00:00 +0100 2702977 http://www.medworm.com/index.php?rid=2702976&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19679726%26dopt%3DAbstract Authors: Magel CR, Shields JD, Brill RW In 1999, a mass mortality of the American lobster (Homarus americanus) occurred in western Long Island Sound (WLIS). Although the etiology of this event remains unknown, bottom water temperature, hypoxia, heavy metal poisoning, and pesticides are potential causal factors. Lobsters from WLIS continue to display signs of morbidity, including lethargy and cloudy grey eyes that contain idiopathic lesions. As the effect of these lesions on lobster vision is unknown, we used electroretinography (ERG) to document changes in visual function in lobsters from WLIS, while using histology to quantify the extent of physical damage. Seventy-three percent of lobsters from WLIS showed damage to photoreceptors and optic nerve fibers, including necrosis, cellular ... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=2702976 Fri, 31 Jul 2009 23:00:00 +0100 2702976 http://www.medworm.com/index.php?rid=2546825&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19556588%26dopt%3DAbstract Authors: Emlet RB, Maslakova SA, Shanks AL, Young CM PMID: 19556588 [PubMed - in process] (Source: The Biological Bulletin) The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=2546825 Sun, 31 May 2009 23:00:00 +0100 2546825 http://www.medworm.com/index.php?rid=2546824&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19556589%26dopt%3DAbstract Authors: Nielsen C The two main types of theories for the evolution of the biphasic life cycles in marine invertebrates are discussed. The "intercalation" theories propose that the larval stages (planktotrophic or lecithotrophic) have evolved as specializations from the ancestral, direct life cycle. The opposing "terminal addition" theories propose that the ancestor was holopelagic and that the adult stage was added to the life cycle with the pelagic stage retained as a planktotrophic larva. It is emphasized that theories based on hypothetical ancestors that were unable to feed must be rejected. This applies to planula theories based on a compact planula. Various arguments against the theories that consider the feeding larvae as ancestral in the major eumetazoan lineages and in particu... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=2546824 Sun, 31 May 2009 23:00:00 +0100 2546824 http://www.medworm.com/index.php?rid=2546823&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19556590%26dopt%3DAbstract Authors: Page LR Asking the right questions about evolution of development, larval morphology, and life history requires knowledge of ancestral state. Two hypotheses dominate current opinion about the ancestral life cycle of bilaterians: the "larva-first" and the "intercalation" hypotheses. Until recently, the larva-first hypothesis was preeminent. This proposes that the original indirect life cycle of bilaterians included a planktotrophic larva followed by a benthic adult. Phylogenetic evidence suggests that a planktotrophic larva is plesiomorphic for echinoderms. A preponderance of developmental studies on echinoderms may have fostered a tendency to extrapolate conclusions about echinoderm development to other clades, particularly the concept that larval and juvenile/adult bodies are... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=2546823 Sun, 31 May 2009 23:00:00 +0100 2546823 http://www.medworm.com/index.php?rid=2546822&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19556591%26dopt%3DAbstract Authors: Moran AL, McAlister JS Egg size is one of the most important aspects of the life history of free-spawning marine organisms, and it is correlated with larval developmental mode and many other life-history characters. Egg size is simple to measure and data are available for a wide range of taxa, but we have a limited understanding of how large and small eggs differ in composition; size is not always the best measure of the characters under selection. Large eggs are generally considered to reflect increased maternal investment, but egg size alone can be a poor predictor of energetic content within and among taxa. We review techniques that have been used to measure the energetic content and biochemical makeup of invertebrate eggs and point out the strengths and difficulties associ... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=2546822 Sun, 31 May 2009 23:00:00 +0100 2546822 http://www.medworm.com/index.php?rid=2546821&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19556592%26dopt%3DAbstract Authors: Forward RB This synthesis reviews the physiological ecology and behavior of larvae of the benthic crab Rhithropanopeus harrisii, which occurs in low-salinity areas of estuaries. Larvae are released rhythmically around the time of high tide in tidal estuaries and in the 2-h interval after sunset in nontidal estuaries. As in most subtidal crustaceans, the timing of larval release is controlled by the developing embryos, which release peptide pheromones that stimulate larval release behavior by the female to synchronize the time of egg hatching. Larvae pass through four zoeal stages and a postlarval or megalopal stage that are planktonic before metamorphosis. They are retained near the adult population by means of an endogenous tidal rhythm in vertical migration. Larvae have seve... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=2546821 Sun, 31 May 2009 23:00:00 +0100 2546821 http://www.medworm.com/index.php?rid=2546820&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19556593%26dopt%3DAbstract Quantifying the "bio-" components in biophysical models of larval transport in marine benthic invertebrates: advances and pitfalls. Biol Bull. 2009 Jun;216(3):257-72 Authors: Metaxas A, Saunders M Biophysical models are being used increasingly, both as predictive tools of larval dispersal for a particular system and for general evaluation of the role of different factors in larval transport. In the results of such models, larval duration, mortality, and behavior in the water column have exhibited pronounced effects on larval dispersal of marine benthic invertebrates. The parameterization of these processes has broadly reflected values from laboratory experiments, but the accuracy of these values is unknown. The pelagic larval duration used in models should be determined by labo... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=2546820 Sun, 31 May 2009 23:00:00 +0100 2546820 http://www.medworm.com/index.php?rid=2546819&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19556594%26dopt%3DAbstract We report development with transitory epidermis in two other species, review evidence from the literature, and suggest that this developmental type is the rule for hoplonemerteans. The hoplonemertean planuliform larva is fundamentally different both from the pilidium larva of the sister group to the Hoplonemertea, the Pilidiophora, and from the hidden trochophore of palaeonemerteans. We discuss the possible function and homology of the larval epidermis in development of other nemerteans and spiralians in general. PMID: 19556594 [PubMed - in process] (Source: The Biological Bulletin) The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=2546819 Sun, 31 May 2009 23:00:00 +0100 2546819 http://www.medworm.com/index.php?rid=2546818&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19556595%26dopt%3DAbstract Authors: Wanninger A Despite the large variation in adult bodyplan phenotypes, a worm-shaped morphology is considered plesiomorphic for both Lophotrochozoa and Bilateria. Although almost all larval and adult lophotrochozoan worms have serially arranged ring muscles in their body wall, a comparison of their ontogeny reveals no less than six different developmental pathways that lead to this homogenous arrangement of ring muscles. However, in all taxa, with the exception of chaetodermomorph molluscs and the segmented annelids, ring muscle development starts with synchronous formation of certain pioneer myocytes, which is thus considered basal for Lophotrochozoa. Recent studies on spiralian neurogenesis revealed remnants of ancestral segmentation in echiurans and sipunculans, thus confirm... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=2546818 Sun, 31 May 2009 23:00:00 +0100 2546818 http://www.medworm.com/index.php?rid=2546817&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19556596%26dopt%3DAbstract Authors: Bishop CD, Hall BK The performance requirements of ciliary band feeding explain the convoluted forms of many marine invertebrate larvae. Convolutions increase surface area and therefore feeding rates per unit body volume. We review recent advances in morphology, neural development, and behavior at settlement of the echinoid Lytechinus pictus and provide new ultrastructural and expression data on larvae of its congener, L. variegatus. Larvae of the echinometrid Colobocentrotus atratus contain neurons identified by their expression of nitric oxide synthase (NOS), indicating that this character is not unique to Lytechinus. We hypothesize that in some echinoids the convoluted shape of the post-oral vibratile lobe (POVL) covaries with the distribution of identified sensory neurons ... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=2546817 Sun, 31 May 2009 23:00:00 +0100 2546817 http://www.medworm.com/index.php?rid=2546816&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19556597%26dopt%3DAbstract Authors: Elia L, Selvakumaraswamy P, Byrne M Larval and juvenile nervous systems (NS) of three asterinid sea stars with contrasting feeding and nonfeeding modes of development were characterized using the echinoderm-specific synaptotagmin antibody. In the feeding bipinnaria and brachiolaria larvae of Patiriella regularis, the species with ancestral-type development, an extensive NS was associated with the ciliary bands (CBs) and attachment complex. Lecithotrophic planktonic (Meridastra calcar) and benthic (Parvulastra exigua) brachiolariae lacked CBs and the associated NS, but had an extensive NS in the attachment complex. The similarity in the distribution and morphology of synaptotagmin immunoreactive neurons and the anatomy of the NS in the attachment complex of these closely relate... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=2546816 Sun, 31 May 2009 23:00:00 +0100 2546816 http://www.medworm.com/index.php?rid=2546815&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19556598%26dopt%3DAbstract Authors: Pochelon PN, Calado R, Dos Santos A, Queiroga H The wide geographical distribution of the Norway lobster, Nephrops norvegicus, results in a delay, with latitudinal decrease, in the larval season from spring to winter. Newly hatched larvae of the species may therefore be exposed to suboptimal levels or types of prey and face intermittent periods of starvation at low latitudes. This work investigated the feeding response of the first two zoeal stages of N. norvegicus under variable prey densities, prey types, feeding histories, and photoperiods. Both zoeae (Z) I and II increased the number of consumed prey with increasing food levels. ZI preferred Artemia sp. nauplii over larger metanauplii, while in ZII, higher ingestion was observed only for metanauplii at higher food concentr... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=2546815 Sun, 31 May 2009 23:00:00 +0100 2546815 http://www.medworm.com/index.php?rid=2546814&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19556599%26dopt%3DAbstract Authors: Burgess SC, Hart SP, Marshall DJ Larval behaviors prior to settlement are important for both dispersal and the likelihood that larvae will encounter settlement habitat. The role of endogenous factors such as larval age and size are likely to be important in determining pre-settlement behavior but are less well understood than exogenous factors. In a simple experiment we explored the role of larval age and size on pre-settlement behavior in two species of bryozoan. We then used the results of this experiment to develop a theoretical model, which explored potential fitness benefits associated with phenotype-dependent changes in larval behavior (i.e., behaviors that changed depending on larval age or larval size) in a heterogeneous environment. In the experiment we delayed the me... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=2546814 Sun, 31 May 2009 23:00:00 +0100 2546814 http://www.medworm.com/index.php?rid=2546813&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19556600%26dopt%3DAbstract Not my "type": larval dispersal dimorphisms and bet-hedging in opisthobranch life histories. Biol Bull. 2009 Jun;216(3):355-72 Authors: Krug PJ When conditions fluctuate unpredictably, selection may favor bet-hedging strategies that vary offspring characteristics to avoid reproductive wipe-outs in bad seasons. For many marine gastropods, the dispersal potential of offspring reflects both maternal effects (egg size, egg mass properties) and larval traits (development rate, habitat choice). I present data for eight sea slugs in the genus Elysia (Opisthobranchia: Sacoglossa), highlighting potentially adaptive variation in traits like offspring size, timing of metamorphosis, hatching behavior, and settlement response. Elysia zuleicae produced both planktotrophic and lecithotrophic ... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=2546813 Sun, 31 May 2009 23:00:00 +0100 2546813 http://www.medworm.com/index.php?rid=2546812&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19556601%26dopt%3DAbstract Authors: Shanks AL I present dispersal distances for 44 species with data on propagule duration (PD) for 40 of these. Data were combined with those in Shanks et al. (2003; Ecol. Appl. 13: S159-S169), providing information on 67 species. PD and dispersal distance are correlated, but with many exceptions. The distribution of dispersal distances was bimodal. Many species with PDs longer than 1 day dispersed less than 1 km, while others dispersed tens to hundreds of kilometers. Organisms with short dispersal distances were pelagic briefly or remained close to the bottom while pelagic. Null models of passively dispersing propagules adequately predict dispersal distance for organisms with short PDs (<1 day), but overestimate dispersal distances for those with longer PDs. These models pred... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=2546812 Sun, 31 May 2009 23:00:00 +0100 2546812 http://www.medworm.com/index.php?rid=2546834&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19366921%26dopt%3DAbstract Authors: Megalou EV, Brandon CJ, Frost WN The escape swim response of the marine mollusc Tritonia diomedea is a well-established model system for studies of the neural basis of behavior. Although the swim neural network is reasonably well understood, little is known about the transmitters used by its constituent neurons. In the present study, we provide immunocytochemical and electrophysiological evidence that the S-cells, the afferent neurons that detect aversive skin stimuli and in turn trigger Tritonia's escape swim response, use glutamate as their transmitter. First, immunolabeling revealed that S-cell somata contain elevated levels of glutamate compared to most other neurons in the Tritonia brain, consistent with findings from glutamatergic neurons in many species. Second, pressur... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=2546834 Tue, 31 Mar 2009 23:00:00 +0100 2546834 http://www.medworm.com/index.php?rid=2546833&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19366922%26dopt%3DAbstract In this study, extracellular recordings were made from the tentacle and peduncle of hydra during bath application of NMDA and d-serine (both at 1 x 10(-5) mol l(-1) to 1 x 10(-9) mol l(-1)) in the presence of 1 x 10(-7) mol l(-1) AMPA or kainate. NMDA/d-serine produced a significant increase in tentacle activity, increasing the rate of tentacle pacemaker pulses (TPs) at 1 x 10(-7) mol l(-1), and small, behaviorally uncorrelated tentacle pulses (SUTPs) at 1 x 10(-5) mol l(-1). The NMDA antagonist, d-2-amino-5-phosphonopentanoic acid (D-AP5), counteracted the effects. NMDA/d-serine (1 x 10(-7) mol l(-1)) also caused a potentially significant (trend) decrease in the rate of small, behaviorally uncorrelated electrical body pulses (SUBPs) and rhythmic potentials (RPs). The effect was counteract... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=2546833 Tue, 31 Mar 2009 23:00:00 +0100 2546833 http://www.medworm.com/index.php?rid=2546832&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19366923%26dopt%3DAbstract Authors: Srinivasan V, Morowitz HJ Chemoautorophs that fix carbon by the reductive tricarboxylic acid cycle represent one of the dominant bacterial life forms that make a major contribution to biomass production. From the viewpoint of biogenesis, construction of a canonical chart of intermediary metabolism for this class of organisms may help us to understand early cellular evolution and point us to the last universal common ancestor. Data-mining the KEGG Pathways database enabled us to integrate required biosynthetic pathways and derive a chart that represents the complete anabolic network of a reductive chemoautotroph. Compounds of this metabolic network together constitute a representative minimal metabolome that comprises 287 metabolites. These compounds have been classified into d... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=2546832 Tue, 31 Mar 2009 23:00:00 +0100 2546832 http://www.medworm.com/index.php?rid=2546831&cid=s_37595_62_f&fid=37595&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19366924%26dopt%3DAbstract Authors: Vize PD Entrained circadian rhythms control many biological processes. These cyclical systems are synchronized by environmental signals but continue to free run for a considerable time when the synchronizing stimuli are removed. In scleractinian corals that reproduce by broadcast spawning, timing processes are essential in ensuring successful fertilization. It is not known whether spawn timing is regulated directly by environmental signals or if it is entrained and regulated by circadian or circalunar rhythms. The genetic components of circadian systems have been studied in considerable detail in microbes, plants, and animals. To identify potential participants in regulating scleractinian circadian systems, we have undertaken a bioinformatic analysis of the transcriptome of la... The Biological Bulletin journals http://www.medworm.com/rss/comments.php?id=2546831 Tue, 31 Mar 2009 23:00:00 +0100 2546831