MedWorm: Zoology

Stress and reproduction in Boiga irregularis with notes on the ultrastructure of the sexual segment of the kidney in squamates

Canadian Journal of Zoology — Sat, 21 Nov 2009 16:00:40 +0100

D. S. Siegel, R. D. Aldridge, C. S. Clark, E. H. Poldemann, and K. M. Gribbins - The reproductive tract of wild-caught male Boiga irregularis (Merrem, 1802) (Brown Treesnake) and the changes that result in these tissues from captivity are described. Wild-caught... (Source: Canadian Journal of Zoology)

MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.

Physiological responses of postprandial red rock crabs (Cancer productus) during emersion

Canadian Journal of Zoology — Fri, 20 Nov 2009 16:17:40 +0100

I. J. McGaw, D. L. Curtis, J. D. Ede, K. J. Ong, F. van Breukelen, and G. G. Goss - The physiological responses of unfed and postprandial red rock crabs (Cancer productus J.W. Randal, 1840) were investigated during periods of emersion. During aerial exposure, oxygen... (Source: Canadian Journal of Zoology)

An analysis of levels of infectious pancreatic necrosis virus in Atlantic salmon, Salmo salar L., broodstock in Scotland between 1990–2002

Journal of Fish Diseases — Fri, 20 Nov 2009 00:00:00 +0100

Throughout this study period the prevalence of infectious pancreatic necrosis virus (IPNV) in Scottish farmed Atlantic salmon was high in the marine environment but relatively low in fresh water. In order to minimize the risk of vertical transmission of infection from parent to progeny, all IPNV infected broodstock populations had to undergo testing of all fish for the virus at the time of stripping and eggs from positive parents were destroyed. Between 1990 and 2002 over 68 000 Atlantic salmon broodfish were individually screened for IPNV by cell culture isolation and enzyme linked immunosorbent assay. Generalized linear mixed models were used to assess the influence of geographical region, age, sex and year on IPNV prevalence in Atlantic salmon broodstock. This analysis determined that t...

Histology and ultrastructure of the salivary glands and salivary pumps in the scorpionfly Panorpa obtusa (Mecoptera: Panorpidae)

Acta Zoologica — Fri, 20 Nov 2009 00:00:00 +0100

Liu, S. and Hua, B. 2009. Histology and ultrastructure of the salivary glands and salivary pumps in the scorpionfly Panorpa obtusa (Mecoptera: Panorpidae). [mdash]Acta Zoologica (Stockholm) xx:xx[ndash]xx The morphology, histology and ultrastructure of the salivary glands and salivary pumps in the scorpionfly Panorpa obtusaCheng 1949 were investigated using light microscopy and scanning and transmission electron microscopy. The salivary glands display a distinct sexual dimorphism. The female has only two small sac-like glands located in the prothorax, while the male possesses six long tubular glands extending into the sixth abdominal segment. The male salivary glands can be divided into five distinct regions. The apical long, thin secretory region possesses numerous secretory cells contain...

The Use of Torpor in Reproductive Female Hemprich’s Long‐Eared Bats (Otonycteris hemprichii)

Physiological and Biochemical Zoology — Thu, 19 Nov 2009 21:18:01 +0100

Physiological and Biochemical Zoology, Volume 0, Issue 0, Page 000, Latest Articles. Abstract We investigated the patterns of torpor use and body temperature (Tb) in reproductive Hemprich’s long‐eared bats (Otonycteris hemprichii; body mass ∼20 g) in the central Negev Desert highlands. We hypothesized that Tb regulation in female O. hemprichii during reproduction is shaped by a trade‐off between the energy and temperature requirements of embryo and pup growth and the mother’s own need to use torpor and passive rewarming to save energy and water. We predicted that patterns of torpor use change during pregnancy but change little if at all during nursing. We used radio telemetry to track, find the roosts of, and measure the skin temperatures of eight pregnant and 15 nursing ba...

Demographic differences among populations of Northern Map Turtles (Graptemys geographica) in intact and fragmented sites

Canadian Journal of Zoology — Thu, 19 Nov 2009 16:20:59 +0100

We examined demographic differences between populations of Northern Map Turtles, Graptemys geographica (Le Sueur, 1817),... (Source: Canadian Journal of Zoology)

MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.

Responding to spatial and temporal variations in predation risk: space use of a game species in a changing landscape of fear

Canadian Journal of Zoology — Thu, 19 Nov 2009 16:20:59 +0100

V. Tolon, S. Dray, A. Loison, A. Zeileis, C. Fischer, and E. Baubet - Predators generate a “landscape of fear” within which prey can minimize the risk of predation by selecting low-risk areas. Depending on the spatial structure of... (Source: Canadian Journal of Zoology)

Modeling haul-out behavior of walruses in Bering Sea ice

Canadian Journal of Zoology — Thu, 19 Nov 2009 16:20:59 +0100

Mark S. Udevitz, Chadwick V. Jay, Anthony S. Fischbach, and Joel L. Garlich-Miller - Understanding haul-out behavior of ice-associated pinnipeds is essential for designing and interpreting population surveys and for assessing effects of potential changes in their ice environments.... (Source: Canadian Journal of Zoology)

The status of taxonomy in Canada and the impact of DNA barcoding

Canadian Journal of Zoology — Thu, 19 Nov 2009 16:20:59 +0100

L. Packer, J. C. Grixti, R. E. Roughley, and R. Hanner - To assess the recent history of taxonomy in Canada and the impact of DNA barcoding upon the field, we performed a survey of various indicators... (Source: Canadian Journal of Zoology)

Comparative temperature in funnel and pit traps

Australian Journal of Zoology — Thu, 19 Nov 2009 14:00:59 +0100

Graham G. Thompson, Scott A. Thompson - Volume 57(5) (Source: Australian Journal of Zoology)

Phylogeographic patterns in reptiles on the New England Tablelands at the south-western boundary of the McPherson Macleay Overlap

Australian Journal of Zoology — Thu, 19 Nov 2009 14:00:58 +0100

D. J. Colgan, D. O'Meally, R. A. Sadlier - Volume 57(5) (Source: Australian Journal of Zoology)

MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.

Interactions between chuditch (Dasyurus geoffroii) and introduced predators: a review

Australian Journal of Zoology — Thu, 19 Nov 2009 14:00:57 +0100

A. S. Glen, P. J. de Tores, D. R. Sutherland, K. D. Morris - Volume 57(5) (Source: Australian Journal of Zoology)

Do bare-nosed wombat (Vombatus ursinus) mounds influence terrestrial macroinvertebrate assemblages in agricultural riparian zones?

Australian Journal of Zoology — Thu, 19 Nov 2009 14:00:56 +0100

Philip Borchard, Ian A. Wright, Clare McArthur - Volume 57(5) (Source: Australian Journal of Zoology)

A three-dimensional geometric morphometric analysis of variation in cranial size and shape in tammar wallaby (Macropus eugenii) populations

Australian Journal of Zoology — Thu, 19 Nov 2009 14:00:55 +0100

Claire Hadley, Nick Milne, Lincoln H. Schmitt - Volume 57(5) (Source: Australian Journal of Zoology)

The cranial morphology of Kayentachelys, an Early Jurassic cryptodire, and the early history of turtles

Acta Zoologica — Thu, 19 Nov 2009 00:00:00 +0100

Gaffney, E. S. and Jenkins, F. A., Jr. 2099. The cranial morphology of Kayentachelys, an Early Jurassic cryptodire, and the early history of turtles. [mdash] Acta Zoologica (Stockholm) xx: 00[ndash]00. The skull morphology of Kayentachelys aprixGaffney et al., 1987, a turtle from the Early Jurassic Kayenta Fm of northern Arizona, demonstrates the presence of cryptodiran synapomorphies in agreement with Gaffney et al. (1987, 1991, 2007), and contrary to the conclusions of Sterli and Joyce (2007), Joyce (2007), Sterli (2008), and Anquetin et al. (2008). Specific characters found in Kayentachelys and diagnostic of cryptodires include the processus trochlearis oticum, the curved processus pterygoideus externus with a vertical plate, and the prefrontal[ndash]vomer contact, which are confirmed a...

Foregut ossicles morphology and feeding of the freshwater anomuran crab Aegla uruguayana (Decapoda, Aeglidae)

Acta Zoologica — Thu, 19 Nov 2009 00:00:00 +0100

Williner, V. 2009. Foregut ossicles morphology and feeding of the freshwater anomuran crab Aegla uruguayana (Decapoda, Aeglidae) [mdash]Acta Zoologica (Stockholm) xx: 00[ndash]00. The acquisition and processing of food is critical to animal survival and reproductive success. This work describes the foregut ossicles of Aegla uruguayana, which have been proposed to impart trophic characteristics. In addition, stomach contents were analysed using Index of Relative Importance and Weighted Result Index to characterize the diet. The Pearre index was applied to analyse trophic selectivity. We found A. uruguayana has a morphological foregut typical of macrophage organisms. Stomach contents included items typical of omnivorous, generalist and opportunistic feeding modes. Vegetal remains included al...

MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.

Age and Breeding Effort as Sources of Individual Variability in Oxidative Stress Markers in a Bird Species

Physiological and Biochemical Zoology — Wed, 18 Nov 2009 23:22:55 +0100

Physiological and Biochemical Zoology, Volume 0, Issue 0, Page 000, Latest Articles. Abstract Oxidative stress is the imbalance between the production of pro‐oxidant substances and the level of antioxidant defenses, which leads to oxidative damage. It has been proposed that senescence is the result of accumulated oxidative damage throughout life. In birds, the sources of individual variability in oxidative stress are still poorly understood. Among these sources, age, as related to senescence, should be particularly relevant. Furthermore, recent findings suggest that breeding effort may also deeply influence susceptibility to oxidative stress. However, there is still no evidence of a link between breeding effort and oxidative damage in any vertebrate. Here we analyzed 288 captive re...

Betaines and Dimethylsulfoniopropionate as Major Osmolytes in Cnidaria with Endosymbiotic Dinoflagellates

Physiological and Biochemical Zoology — Wed, 18 Nov 2009 23:16:13 +0100

Physiological and Biochemical Zoology, Volume 0, Issue 0, Page 000, Latest Articles. Abstract Most marine invertebrates and algae are osmoconformers whose cells accumulate organic osmolytes that provide half or more of cellular osmotic pressure. These solutes are primarily free amino acids and glycine betaine in most invertebrates and small carbohydrates and dimethylsulfoniopropionate (DMSP) in many algae. Corals with endosymbiotic dinoflagellates (Symbiodinium spp.) have been reported to obtain from the symbionts potential organic osmolytes such as glycerol, amino acids, and DMSP. However, corals and their endosymbionts have not been fully analyzed for osmolytes. We quantified small carbohydrates, free amino acids, methylamines, and DMSP in tissues of the corals Fungia scutaria, Poc...

Spotting animals in natural scenes: efficiency of humans and monkeys at very low contrasts.

Animal Cognition — Wed, 18 Nov 2009 00:00:00 +0100

Authors: Macé MJ, Delorme A, Richard G, Fabre-Thorpe M The ability of monkeys to categorize objects in visual stimuli such as natural scenes might rely on sets of low-level visual cues without any underlying conceptual abilities. Using a go/no-go rapid animal/non-animal categorization task with briefly flashed achromatic natural scenes, we show that both human and monkey performance is very robust to large variations of stimulus luminance and contrast. When mean luminance was increased or decreased by 25-50%, accuracy and speed impairments were small. The largest impairment was found at the highest luminance value with monkeys being mainly impaired in accuracy (drop of 6% correct vs. <1.5% in humans), whereas humans were mainly impaired in reaction time (20 ms increase in media...

Establishment, characterization, virus susceptibility and transfection of cell lines from cobia, Rachycentron canadum (L.), brain and fin

Journal of Fish Diseases — Wed, 18 Nov 2009 00:00:00 +0100

Establishment and characterization of two cobia, Rachycentron canadum, cell lines derived from cobia brain (CB) and cobia fin (CF) are described. Caudal fin and brain from juvenile cobia were dissociated for 30 and 10 min, respectively, in phosphate-buffered saline containing 0.25% trypsin at 25 °C. The optimal culture condition for both dissociated cells (primary cell culture) was at 28 °C in Leibovitz-15 medium containing 10% foetal bovine serum. The cells have been sub-cultured at a ratio of 1:2 for more than 160 passages over a period of 3 years. Origin of the cultured cells was verified by comparison of their sequences of mitochondrial cytochrome oxidase subunit I genes (cox I) with the cox 1 sequence from cobia muscle tissue. The cell lines showed polyploidy. No mycoplasma contamin...

Study on bioactive compounds of in vitro cultured Calculus Suis and natural Calculus Bovis1

Animal Science Journal — Wed, 18 Nov 2009 00:00:00 +0100

The purpose of the study was to investigate bioactive compounds of in vitro cultured Calculus Suis and natural Calculus Bovis obtained as valuable by-products from animals used for meat production. The results showed that the components of natural Calculus Bovis were rich in bilirubin and biliverdin and had higher content of essential amino acids. The major amino acids of in vitro cultured Calculus Suis were identified as glycine, alanine, glutamic acid and aspartic acid, and those for natural Calculus Bovis were found to be glutamic acid, aspartic acid, proline, and arginine. The methionine and cysteine contents of precursors for glutathione in natural Calculus Bovis were significantly higher than those of in vitro cultured Calculus Suis. The mineral contents of zinc, iron and manganese o...

MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.

Effects of central administration of glucagon on feed intake and endocrine responses in sheep

Animal Science Journal — Wed, 18 Nov 2009 00:00:00 +0100

This study was conducted to investigate effects of glucagon intracerebroventricularly administered on feed intake and endocrine changes in sheep. Four male sheep (48[ndash]55 kg BW) were used. The animals were acclimatized to be fed alfalfa hay cubes at 12.00 hour. Human glucagon (40 and 80 µg/0.5 mL) was injected into the lateral ventricle at 12.00 hour. Blood samples were taken every 10 min from 30 min before to 180 min after the glucagon injection. Soon after the injection, the animals were given alfalfa hay cubes, and the amounts of the feed eaten within 2 h were measured. Feed intakes were significantly (P < 0.05) suppressed by 80 µg of glucagon. Plasma glucose levels in control animals were gradually decreased after the feeding, whilst those in glucagon-treated animals were tempora...

Oral administration of Lactobacillus plantarum Lq80 and Megasphaera elsdenii iNP-001 induces efficient recovery from mucosal atrophy in the small and the large intestines of weaning piglets

Animal Science Journal — Wed, 18 Nov 2009 00:00:00 +0100

Weaning causes atrophy of intestinal mucosa and a drop of IgA protection in piglets which increases vulnerability to pathogenic infections. Probiotic lactobacilli may support recovery from such weaning stresses. Butyrate-produce bacteria may support the growth of colonic mucosa. Megasphaera elsdenii, a lactate-utilizing butyrate producer, may help butyrate production particularly when combined with lactobacilli. Weaned piglets (Experiment 1: 20 days old, Experiment 2: 28 days old) were orally dosed once a day with either (L) 1010 (cell/dose) L. plantarum Lq80, or (LM) 1010 (cell/dose) Lq80 with 109 (cell/dose) M. elsdenii iNP-001. Lq80 was contained in capsules resistant to gastric digestion. M. elsdenii was contained in capsules resistant to gastric and intestinal digestion. An untreated ...

Physiological responses of young cross-bred calves immediately after long-haul road transportation and after one week of habituation

Animal Science Journal — Wed, 18 Nov 2009 00:00:00 +0100

We investigated 10 suckling cross-bred calves (Japanese Black (Wagyu) × Holstein) and collected data on the physiological stress responses of the young calves to long-haul road transportation. All calves were male and 21[ndash]47 days of age. The calves were obtained at a livestock market and were transported from the market to the university in a commercial livestock vehicle. The total haul distance and time were 306.9 km and 7 h, respectively. The calves were deprived of food and water during transportation. Blood samples, electrocardiograms, and rectal temperatures were collected immediately after transportation and after one week of habituation at the university. Serum pH was significantly lower (P < 0.01), while serum triiodothyronine, aspartate aminotransferase, non-esterified fatty...

Subjective value of risky foods for individual domestic chicks: a hierarchical Bayesian model.

Animal Cognition — Tue, 17 Nov 2009 00:00:00 +0100

Authors: Kawamori A, Matsushima T For animals to decide which prey to attack, the gain and delay of the food item must be integrated in a value function. However, the subjective value is not obtained by expected profitability when it is accompanied by risk. To estimate the subjective value, we examined choices in a cross-shaped maze with two colored feeders in domestic chicks. When tested by a reversal in food amount or delay, chicks changed choices similarly in both conditions (experiment 1). We therefore examined risk sensitivity for amount and delay (experiment 2) by supplying one feeder with food of fixed profitability and the alternative feeder with high- or low-profitability food at equal probability. Profitability varied in amount (groups 1 and 2 at high and low variance) or in ...

Pathogen Dose Infectivity Curves as a Method to Analyze the Distribution of Host Susceptibility: A Quantitative Assessment of Maternal Effects after Food Stress and Pathogen Exposure

The American Naturalist — Fri, 13 Nov 2009 21:42:41 +0100

The American Naturalist, Volume 0, Issue 0, Page 000, Latest Articles. Abstract: Stress conditions have been found to change the susceptibility of hosts or their offspring to infection. The usual method of testing at just one parasite dose level does not allow conclusions on the distribution of susceptibility. To better understand the epidemiology and evolution of host‐parasite systems, however, knowledge about the distribution of host susceptibility, the parameters that characterize it, and how it changes in response to environmental conditions is required. We investigated transgenerational effects of different stress factors by exposing Daphnia magna to standard conditions, to low food levels, or to a high dose of the bacterial pathogen Pasteuria ramosa and then measuring the sus...

MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.

Female Zebra Finches (Taeniopygia guttata) Are Chronically but Not Cumulatively “Anemic” during Repeated Egg Laying in Response to Experimental Nest Predation

Physiological and Biochemical Zoology — Fri, 13 Nov 2009 19:51:07 +0100

In this study, we investigated the effect of repeated cycles of egg production in response to experimental nest predation (egg removal) on hematological traits in female zebra finches (Taeniopygia guttata). We predicted that if the negative effect of egg production on hematocrit and hemoglobin concentration was cumulative, with anemia being proportional to reproductive effort, then females laying more clutches, or laying successive clutches without recovery during incubation, would show greater reproductive anemia. In contrast, if females maintain hematocrit and hemoglobin concentration at some minimum functional level independent of reproductive effort, then there should be no difference in hematological traits among females laying two or more successive clutches. Our results supported th...

Parent‐Offspring Conflict and the Evolution of Dispersal Distance

The American Naturalist — Fri, 13 Nov 2009 15:41:49 +0100

The American Naturalist, Volume 0, Issue 0, Page 000, Latest Articles. Abstract: Parent‐offspring conflict emerges in many different contexts, but a rarely emphasized perspective is that of space as a resource that is allocated or acquired through dispersal. Early theoretical work has shown that there are different optima in rates of dispersal between parents and offspring. Here we examine this principle when space is explicitly modeled and dispersal is achieved through a dispersal kernel. We find a consistent pattern that selection favors longer dispersal distances under maternal control of dispersal (e.g., maternal tissue surrounding a seed) compared with scenarios where offspring themselves control dispersal (as in many animals). Intriguingly, offspring control leads to better r...

A Porous Convection Model for Grass Patterns

The American Naturalist — Fri, 13 Nov 2009 15:29:38 +0100

We present a new hypothesis that suggests that fluid convection and chill damage to plants could form vegetation patterns with wavelengths ≈1–2 times the plant height. Previous hypotheses for small‐scale vegetation pattern formation relied on a Turing process driven by competition for water, which is thought to occur in large vegetation patterns. Predictions of the new hypothesis were consistent with properties of natural grass patterns in North Carolina, contradicting the Turing hypothesis. These results indicate that similarities in pattern morphology should not be interpreted as implying similarities in the pattern‐forming processes, that small‐wavelength vegetation patterns may arise from mechanisms that are distinct from those generating long‐wavelength vegetation patterns...

Bonobos, chimpanzees, gorillas, and orang utans use feature and spatial cues in two spatial memory tasks.

Animal Cognition — Fri, 13 Nov 2009 00:00:00 +0100

Authors: Kanngiesser P, Call J Animals commonly use feature and spatial strategies when remembering places of interest such as food sources or hiding places. We conducted three experiments with great apes to investigate strategy preferences and factors that may shape them. In the first experiment, we trained 17 apes to remember 12 different food locations on the floor of their sleeping room. The 12 food locations were associated with one feature cue, so that feature and spatial cues were confounded. In a single test session, we brought the cues into conflict and found that apes, irrespective of species, showed a preference for a feature strategy. In the second experiment, we used a similar procedure and trained 25 apes to remember one food location on a platform in front of them. On av...

A comparative molecular study of the presence of "Candidatus arthromitus" in the digestive system of rainbow trout, Oncorhynchus mykiss (Walbaum), healthy and affected with rainbow trout gastroenteritis

Journal of Fish Diseases — Fri, 13 Nov 2009 00:00:00 +0100

Observations were made using histopathological techniques in conjunction with a nested polymerase chain reaction (PCR) protocol for the specific detection of "Candidatus arthromitus" on DNA extracted from wax-embedded tissues and fresh digestive contents of rainbow trout. Samples positive for "Candidatus arthromitus" DNA included fish with rainbow trout gastroenteritis (RTGE), clinically normal cohabiting fish, and apparently healthy controls from RTGE positive and RTGE negative sites. The results obtained from the PCR were confirmed by nucleotide sequencing. "Candidatus arthromitus" DNA was found in distal intestine as well as in sections of pyloric caeca, suggesting that both these locations are appropriate for molecular detection of "Candidatus arthromitus" DNA in trout. Furthermore, ra...

MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.

Cellular components of probiotics control Yersinia ruckeri infection in rainbow trout, Oncorhynchus mykiss (Walbaum)

Journal of Fish Diseases — Thu, 12 Nov 2009 00:00:00 +0100

Subcellular components of the probiotics Aeromonas sobria GC2 and Bacillus subtilis JB-1, when administered to rainbow trout, Oncorhynchus mykiss, conferred protection against a new biogroup of Yersinia ruckeri. Thus, intraperitoneal or intramuscular injection of rainbow trout with cell wall proteins (CWPs), outer membrane proteins (OMPs), lipopolysaccharides (LPS), whole cell proteins (WCPs) and live cells followed by challenge on day 8 with Y. ruckeri led to 80[ndash]100% survival compared with 10% survival in the controls. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) profiles of WCPs and OMPs from GC2 had 10 and 5 variable protein bands in comparison to 11 and 5 bands in the WCPs and CWPs from JB-1. Proteomic analyses were employed following SDS-PAGE to categori...

Utilization of tissue habitats by Myxobolus wulii Landsberg & Lom, 1991 in different carp hosts and disease resistance in allogynogenetic gibel carp: redescription of M. wulii from China and Japan

Journal of Fish Diseases — Thu, 12 Nov 2009 00:00:00 +0100

Myxobolus wulii (=Myxosoma magna) was first described from the gills of goldfish, Carassius auratus auratus, in China. Subsequently, a myxosporean infecting the hepatopancreas of allogynogenetic gibel carp, C. auratus gibelio, was designated as a different species, Myxobolus guanqiaoensis, although the morphological features were almost identical to those of M. wulii. In Japan, an unidentified Myxobolus sp. was found in the gills and hepatopancreas of goldfish. Morphological and molecular analyses in the present study identified these myxosporeans as M. wulii, which was thus shown to use different habitats in the host fish. Phylogenetic analyses of small subunit ribosomal RNA gene sequences showed that M. wulii is closely related to two gill-infecting Myxobolus species, M. ampullicapsulatu...

Host response to the chondracanthid copepod Chondracanthus goldsmidi, a gill parasite of the striped trumpeter, Latris lineata (Forster), in Tasmania

Journal of Fish Diseases — Thu, 12 Nov 2009 00:00:00 +0100

In this study C. goldsmidi was associated with extensive epithelial hyperplasia and necrosis. Pathological changes were most pronounced near the parasite's attachment site, with papilloma-like growths surrounding the entire parasite resulting in deformation of the filament. The number of mucous cells increased near the parasite attachment sites on both the opercula and gills. Mast cells were absent in healthy gills; in contrast numerous mast cells were identified in the papilloma-like growths. Immunostaining identified piscidin-positive mast cells in the papilloma-like growths, presenting the first evidence of piscidin in the family Latridae. (Source: Journal of Fish Diseases)

A sensitive FRET probe assay for the selective detection of Mycobacterium marinum in fish

Journal of Fish Diseases — Thu, 12 Nov 2009 00:00:00 +0100

Mycobacterium marinum is the causative agent of mycobacteriosis in wild and cultured fish and of atypical infection in humans. For the diagnosis of M. marinum, cultural and traditional polymerase chain reaction (PCR) methods are currently used. However, these protocols, although able to discriminate within Mycobacterium spp., have proved to be time-consuming or difficult to carry out. For this reason, the aim of this study was to obtain a rapid and specific diagnostic tool to quantify fish Mycobacterium spp. or to discriminate M. marinum from other mycobacteria. A primary PCR amplification with SYBR Green had a detection limit (dl) of 102Mycobacterium DNA copies with a log-linear quantification range up to 104 (R2 = 0.99). The second PCR using FRET probes, flanking a region containing spec...

Attenuated Mycobacterium marinum protects zebrafish against mycobacteriosis

Journal of Fish Diseases — Thu, 12 Nov 2009 00:00:00 +0100

(Source: Journal of Fish Diseases)

MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.

Complete sequencing of Tunisian redspotted grouper nervous necrosis virus betanodavirus capsid gene and RNA-dependent RNA polymerase gene

Journal of Fish Diseases — Thu, 12 Nov 2009 00:00:00 +0100

This study reports on the characterization of the full RNA2 sequence of a Tunisian betanodavirus with a length of 1433 nt, containing a 339 amino acid open-reading frame encoding the CP, and typing to the redspotted grouper nervous necrosis virus Ia genotype following phylogenetic analysis. The homology of the capsid protein to other betanodaviruses or alphanodaviruses was compared. In addition, a full length RNA1 sequence of 3104 nt encoding a 982 amino acid RNA-dependent RNA polymerase was obtained. (Source: Journal of Fish Diseases)

Diet of the squirrel glider in a fragmented landscape near Mackay, central Queensland

Australian Journal of Zoology — Wed, 11 Nov 2009 14:00:59 +0100

Tina Ball, Eddie Adams, Ross L. Goldingay - Volume 57(5) (Source: Australian Journal of Zoology)

Ant-mimicking spider, Myrmarachne species (Araneae : Salticidae), distinguishes its model, the green ant, Oecophylla smaragdina, from a sympatric Batesian O. smaragdina mimic, Riptortus serripes (Hemiptera : Alydidae)

Australian Journal of Zoology — Wed, 11 Nov 2009 14:00:58 +0100

Fadia Sara Ceccarelli - Volume 57(5) (Source: Australian Journal of Zoology)

Mycobacteria isolated from Chesapeake Bay fish

Journal of Fish Diseases — Tue, 10 Nov 2009 00:00:00 +0100

Mycobacteriosis in fish can result in ulcers, emaciation, and in some cases death. Mycobacteria have been previously isolated from a variety of Chesapeake Bay fish species, and the current study was designed to identify potential host specificity and location fidelity of mycobacterial isolates. Mycobacteria were isolated from wild fish of the Chesapeake Bay collected from the Upper Bay, the Choptank River, Herring Bay, the Chicamacomico River, the Pocomoke River and the Potomac River in 2003[ndash]2006. Mycobacterial isolates were recovered from striped bass, Morone saxatilis, Atlantic menhaden, Brevoortia tyrannus, white perch, Morone americana, summer flounder, Paralichthys dentatus, spot, Leiostomus xanthurus, largemouth bass, Micropterus salmoides, channel catfish, Ictalurus punctatus,...

MidExDB: A database of Drosophila CNS midline cell gene expression

BMC Developmental Biology - Latest articles — Tue, 10 Nov 2009 00:00:00 +0100

Conclusion: MidExDB integrates large-scale gene expression data with the ability to identify individual cell types providing the foundation for detailed genetic, molecular, and biochemical studies of CNS midline cell neuronal and glial development and function. This information has general relevance for the study of nervous system development in other organisms, and also provides insight into transcriptional regulation. (Source: BMC Developmental Biology - Latest articles)

MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.

Plant Water Use Affects Competition for Nitrogen: Why Drought Favors Invasive Species in California

The American Naturalist — Mon, 09 Nov 2009 17:41:08 +0100

The American Naturalist, Volume 0, Issue 0, Page 000, Latest Articles. Abstract: Classic resource competition theory typically treats resource supply rates as independent; however, nutrient supplies can be affected by plants indirectly, with important consequences for model predictions. We demonstrate this general phenomenon by using a model in which competition for nitrogen is mediated by soil moisture, with competitive outcomes including coexistence and multiple stable states as well as competitive exclusion. In the model, soil moisture regulates nitrogen availability through soil moisture dependence of microbial processes, leaching, and plant uptake. By affecting water availability, plants also indirectly affect nitrogen availability and may therefore alter the competitive outcome...

Environmental Dependence of Thermal Reaction Norms: Host Plant Quality Can Reverse the Temperature‐Size Rule

The American Naturalist — Mon, 09 Nov 2009 17:40:45 +0100

The American Naturalist, Volume 0, Issue 0, Page 000, Latest Articles. Abstract: The temperature‐size rule, a form of phenotypic plasticity in which decreased temperature increases final size, is one of the most widespread patterns in biology, particularly for ectotherms. Identifying the environmental conditions in which this pattern is reversed is key to understanding the generality of the rule. We use wild and domesticated populations of the tobacco hornworm Manduca sexta and the natural host plants of this species to explore the consequences of resource quality for the temperature‐size rule. Manduca sexta reared on a high‐quality host, tobacco (Nicotiana tabacum), followed the temperature‐size rule, with larger final sizes at lower temperatures. In contrast, M. sexta reare...

Testing Spatial Theories of Plant Coexistence: No Consistent Differences in Intra‐ and Interspecific Interaction Distances

The American Naturalist — Fri, 06 Nov 2009 21:51:51 +0100

We examined how intraspecific and interspecific competition scales with neighbor distance in a target‐neighbor greenhouse competition experiment. Individuals from co‐occurring forbs from calcareous grasslands were grown in isolation and with single conspecific or heterospecific neighbors at distances of 5, 10, or 15 cm (Plantago lanceolata vs. Plantago media and Hieracium pilosella vs. Prunella grandiflora). Neighbor effects were strong and declined with distance. Interaction distances varied greatly within and between species, but we found no evidence for heteromyopia. Instead, neighbor identity effects were mostly explained by relative size differences between target and neighbor. We found a complex interaction between final neighbor size and identity such that neighbor identity may ...

Pollination Efficiency and the Evolution of Specialized Deceptive Pollination Systems

The American Naturalist — Fri, 06 Nov 2009 21:47:58 +0100

The American Naturalist, Volume 0, Issue 0, Page 000, Latest Articles. Abstract: The ultimate causes of evolution of highly specialized pollination systems are little understood. We investigated the relationship between specialization and pollination efficiency, defined as the proportion of pollinated flowers relative to those that experienced pollen removal, using orchids with different pollination strategies as a model system. Rewarding orchids showed the highest pollination efficiency. Sexually deceptive orchids had comparably high pollination efficiency, but food‐deceptive orchids had significantly lower efficiency. Values for pollinator sharing (a measure of the degree of generalization in pollination systems) showed the reverse pattern, in that groups with high pollination ef...

Spring migration routes and chronology of surf scoters (Melanitta perspicillata): a synthesis of Pacific coast studies

Canadian Journal of Zoology — Fri, 06 Nov 2009 16:07:01 +0100

S.E.W. De La Cruz, J. Y. Takekawa, M. T. Wilson, D. R. Nysewander, J. R. Evenson, D. Esler, W. S. Boyd, and D. H. Ward - Understanding interconnectivity among wintering, stopover, and breeding areas of migratory birds is pivotal to discerning how events occurring in each might have a cross-seasonal effect... (Source: Canadian Journal of Zoology)

MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.

No evidence for developmental plasticity of color patterns in response to rearing substrate in pygmy grasshoppers

Canadian Journal of Zoology — Fri, 06 Nov 2009 16:07:01 +0100

M. Karlsson, J. Johansson, S. Caesar, and A. Forsman - Color polymorphisms in animals may result from genetic polymorphisms, developmental plasticity, or a combination where some phenotypic components are under strong genetic control and other... (Source: Canadian Journal of Zoology)

The Misuse of BLUP in Ecology and Evolution

The American Naturalist — Thu, 05 Nov 2009 23:15:56 +0100

The American Naturalist, Volume 0, Issue 0, Page 000, Latest Articles. Abstract: Best linear unbiased prediction (BLUP) is a method for obtaining point estimates of a random effect in a mixed effect model. Over the past decade it has been used extensively in ecology and evolutionary biology to predict individual breeding values and reaction norms. These predictions have been used to infer natural selection, evolutionary change, spatial‐genetic patterns, individual reaction norms, and frailties. In this article we show analytically and through simulation and example why BLUP often gives anticonservative and biased estimates of evolutionary and ecological parameters. Although some concerns with BLUP methodology have been voiced before, the scale and breadth of the problems have proba...

Why Do Calypte Hummingbirds “Sing” with Both Their Tail and Their Syrinx? An Apparent Example of Sexual Sensory Bias

The American Naturalist — Thu, 05 Nov 2009 23:14:56 +0100

The American Naturalist, Volume 0, Issue 0, Page 000, Latest Articles. Abstract: Courtship displays frequently include complex signals that females use to pick a mate. Male Costa’s hummingbirds (Calypte costae) generate two acoustic signals during courtship: a vocal song produced close to a female and a dive‐sound produced during a courtship dive. The song and dive‐sound sound similar, and both were assumed to be produced vocally by the syrinx. Here, we show that they are not; whereas the song is produced by the syrinx, the dive‐sound is produced by high‐frequency fluttering of the outermost tail feathers. The Anna’s hummingbird (Calypte anna), sister to the Costa’s, also sings a vocal song and produces a dive‐sound with the wings and outermost tail feathers that soun...

Breakdown in Postmating Isolation and the Collapse of a Species Pair through Hybridization

The American Naturalist — Thu, 05 Nov 2009 23:13:20 +0100

The American Naturalist, Volume 0, Issue 0, Page 000, Latest Articles. Abstract: Species that evolved through ecological speciation and that lack intrinsic genetic incompatibilities may nonetheless be maintained by extrinsic postmating isolating barriers that impose selection against hybrids. These species, however, may be vulnerable to a breakdown in postmating isolation. Here, we investigate a model system for ecological speciation: sympatric limnetic‐benthic pairs of threespine sticklebacks. Recently, stickleback hybrid abundance in Enos Lake has increased. Given that ecological selection against hybrids was historically an important component of total reproductive isolation, we tested whether ecologically dependent postmating isolation is still functioning. We compared body sha...

Adaptation versus Allometry: Population and Body Mass Effects on Hypoxic Metabolism in Fundulus grandis

Physiological and Biochemical Zoology — Thu, 05 Nov 2009 20:23:28 +0100

Physiological and Biochemical Zoology, Volume 0, Issue 0, Page 000, Latest Articles. Abstract Hypoxia has significant effects on organisms, from metabolic reduction to death, and could be an important evolutionary force affecting the variation among populations within a species. To determine intraspecific variation in hypoxic metabolism and the effect of body mass, we examine rates of oxygen consumption ($\dot{\mathrm{M}}\textsc{$o$}_{2}$) at seven oxygen concentrations among seven populations of Fundulus grandis that inhabit a mosaic of habitats with different frequencies and intensities of hypoxia. For $\dot{\mathrm{M}}\textsc{$o$}_{2}$, there is a significant interaction ($P< 0.05$) between body mass and oxygen concentrations: log10 body mass:log10 $\dot{\mathrm{M}}\textsc{$o$}_{2...

MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.

Outbreaks of viral nervous necrosis in juvenile and adult farmed Atlantic cod, Gadus morhua L., in Norway

Journal of Fish Diseases — Thu, 05 Nov 2009 00:00:00 +0100

(Source: Journal of Fish Diseases)

Space‐Time Relatedness and Hamilton’s Rule for Long‐Lasting Behaviors in Viscous Populations

The American Naturalist — Wed, 04 Nov 2009 22:01:41 +0100

The American Naturalist, Volume 0, Issue 0, Page 000, Latest Articles. Abstract: Genes affect not only the behavior and fitness of their carriers but also that of other individuals. According to Hamilton’s rule, whether a mutant gene will spread in the gene pool depends on the effects of its carrier on the fitness of all individuals in the population, each weighted by its relatedness to the carrier. However, social behaviors may affect not only recipients living in the generation of the actor but also individuals living in subsequent generations. In this note, I evaluate space‐time relatedness coefficients for localized dispersal. These relatedness coefficients weight the selection pressures on long‐lasting behaviors, which stem from a multigenerational gap between phenotypic e...

Stress and Aversive Learning in a Wild Vertebrate: The Role of Corticosterone in Mediating Escape from a Novel Stressor

The American Naturalist — Wed, 04 Nov 2009 21:45:33 +0100

The American Naturalist, Volume 0, Issue 0, Page 000, Latest Articles. Abstract: Elevated plasma corticosterone during stressful events is linked to rapid changes in behavior in vertebrates and can mediate learning and memory consolidation. We tested the importance of acute corticosterone elevation in aversive learning of a novel stressor by wild male eastern fence lizards (Sceloporus undulatus). We found that inhibiting corticosterone elevation (using metyrapone, a corticosterone synthesis blocker) during an encounter with a novel attacker impaired immediate escape responses and limited learning and recall during future encounters. In the wild and in outdoor enclosures, lizards whose acute corticosterone response was blocked by an earlier metyrapone injection did not alter their esc...

Tapeworm (Hymenolepis diminuta) infection in flour beetles (Tribolium confusum): does it cause a trade-off between host fecundity and egg size?

Canadian Journal of Zoology — Wed, 04 Nov 2009 16:42:40 +0100

Allen W. Shostak - Inter- and intra-specific comparisons commonly reveal an inverse relationship between fecundity and offspring size. Many animals also vary egg size in response to environmental conditions.... (Source: Canadian Journal of Zoology)

Prevalence of porcine reproductive and respiratory syndrome virus and porcine circovirus type 2 in piglets after weaning on a commercial pig farm in Japan

Animal Science Journal — Wed, 04 Nov 2009 00:00:00 +0100

To investigate the transition in concentration of porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV2) and antibody for these viruses in serum, serum samples were collected from 29 pigs on weaning day and at 7, 14, 21, 28, 53, 84, and 120 days after weaning. The concentration of circulated PRRSV and PCV2 in serum was measured by real-time RT-PCR and real-time PCR, respectively. The specific antibody for PRRSV and PCV2 was measured using ELISA. PRRSV was not detected on 0 days post-weaning (dpw). The specific antibody for PRRSV began to increase as the concentration of PRRSV in serum increased, and the level of PRRSV then tended to decrease. PCV2 was detected in 12 of 28 pigs on 0 dpw. The concentration of PCV2 and the specific antibody for PCV2 s...

MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.

The influence of fig proteases on the inhibition of angiotensin I-converting and GABA formation in meat

Animal Science Journal — Tue, 03 Nov 2009 00:00:00 +0100

The purposes of this research were to use fig protease for texture tenderizing, and to inhibit angiotensin I-converting enzyme (ACE) action and [gamma]-aminobutyric acid (GABA) formation of meat. Liberated peptides by the enzymatic action of fig protease in processing meat and free amino acids were determined and ACE inhibitory activity was assayed. Meat treated with fig protease became tender as indicated by shear force value (SFV) which was half of those of non-fig treated meat during storage even at 5°C. Liberated peptides, free amino acids and GABA increased while extremely low levels of Glu were detected after storage. The optimal temperature of fig protease against meat was 80°C. However, the activity of fig protease decreased after pre-heating more than 40°C. High ACE inhibitory ...

The role of intramuscular connective tissue in meat texture

Animal Science Journal — Tue, 03 Nov 2009 00:00:00 +0100

The structure, composition and amount of intramuscular connective tissue (IMCT) vary tremendously between muscles, species and breeds, and certainly contribute to meat texture. With animal growth, collagen crosslinks become more stable, and the structural integrity of IMCT increases. These changes increase the mechanical properties of IMCT, contributing to the toughening of meat. Intramuscular fat deposits, mainly in the perimysium between muscle fiber bundles, result in marbling. This causes the remodeling of IMCT structures and reduces the mechanical strength of IMCT, contributing to the tenderization of beef. The IMCT has been thought to be rather immutable compared to myofibrils during postmortem ageing of meat. However, recent studies have shown the disintegration of IMCT during postm...

Interaction between myostatin and extracellular matrix components

Animal Science Journal — Tue, 03 Nov 2009 00:00:00 +0100

Myostatin, a member of the TGF-[beta] superfamily, is a negative regulator of skeletal muscle mass. We have recently demonstrated that decorin binds to myostatin in vitro, and that immobilized decorin within the collagen matrix prevents myostatin-mediated inhibition of myoblast proliferation. However, little is known about other ECM molecules that bind to myostatin and modulate its activity. Thus, in the present study, we investigated the interaction of several other ECM molecules with myostatin. We here show that fibromodulin, fibronectin and laminin bind to myostatin in the presence of Zn2+ with a dissociation constant (KD) of 10[minus]10[sim]10[minus]8 mol/L. Fibromodulin shows the highest affinity for myostatin among them. These results suggest that these ECM molecules may modulate myo...

Effects of high potassium chloride supplementation on water intake, urine volume and nitrogen balance in mice

Animal Science Journal — Tue, 03 Nov 2009 00:00:00 +0100

Sixteen ICR male mice were assigned to a control diet group or a KCl diet group in metabolic cages to clarify the effects of KCl supplementation on water intake, urine volume and N balance, and 5% of KCl was supplemented in KCl diets for 4 or 8 weeks. Bodyweight of KCl supplemented mice was significantly higher than that of control mice from 24 to 28 days after treatment. Feed intake, water intake and urine volume of KCl supplemented mice were significantly higher than those of control mice, and the increased water intake and urine volume in KCl supplemented mice were 4.49 and 4.15 g, respectively. Urinary N, K and Cl excretion were significantly higher in KCl supplemented mice. Although N retention was not significantly different between control and KCl supplemented mice, N retention in K...

Regional specialization of the Ganglion cell density in the retina of the Ostrich (Struthio camelus)

Animal Science Journal — Tue, 03 Nov 2009 00:00:00 +0100

In this study, retinal whole-mount specimens were prepared and stained with 0.1% cresyl violet for the ganglion cell study in the Ostrich (Struthio camelus). The total number, distribution, and size of these cells were determined in different retinal regions. The mean total number of ganglion cells (three retinas) was 1 435 052 with an average density of 652 cells/mm2. The temporo [ndash] nasal area of the retina with high cell density were identified with the peak of 7525 cells/mm2 in the central area. The size of most ganglion cells ranged from 113[ndash]403 µm2, with smaller cells predominating along the temporo-nasal streak above the optic disc and larger cells comprising more of the peripheral regions. The average thickness of the retina was 196 µm. The central area was the thickest...

MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.

The T allele at the g.1471620G>T in the EDG1 gene associated with high marbling in Japanese Black cattle is at a low frequency in breeds not selected for marbling

Animal Science Journal — Tue, 03 Nov 2009 00:00:00 +0100

Our previous study detected a single nucleotide polymorphism (SNP), g.1471620G>T, in the 5' flanking region of the endothelial differentiation sphingolipid G-protein-coupled receptor 1 (EDG1) gene, which has been considered as a positional functional candidate for the gene responsible for marbling, and showed association of the g.1471620G>T SNP with marbling in Japanese Black beef cattle. In the present study, we investigated the allele frequency distribution of the g.1471620G>T SNP among the 5 cattle breeds, Japanese Black, Japanese Brown, Japanese Short Horn, Holstein, and Brown Swiss breeds. The T allele at the g.1471620G>T SNP associated with high marbling was found at high frequency in Japanese Black breed that has been subjected to a strong selection for high marbling, while the alle...

Early metaphase II oocytes treated with dibutyryl cyclic adenosine monophosphate provide suitable recipient cytoplasm for the production of miniature pig somatic cell nuclear transfer embryos

Animal Science Journal — Tue, 03 Nov 2009 00:00:00 +0100

We investigated the effects of in vitro maturation duration and treatment with dibutyryl cyclic adenosine monophosphate (dbcAMP) on the blind enucleation efficiency and developmental competence of miniature pig somatic cell nuclear transfer (SCNT) embryos. Oocytes were cultured for 22 h in NCSU-23 medium with or without 1 mM dbcAMP and then additionally cultured in dbcAMP-free NCSU-23 for 14, 18, or 22 h. Regardless of dbcAMP treatment, the rate of nuclear maturation reached a plateau at 36 and 40 h. However, mitochondrial distribution, a marker for cytoplasmic maturation, differed between the dbcAMP-untreated oocytes at 36 h and dbcAMP-treated oocytes at 40 h. The metaphase II chromosomes were adjacent to the first polar body in 68.8% and 63.5% of the dbcAMP-untreated oocytes at 36 h and ...

Relative Abundance of Xiphophorus Fishes and Its Effect on Sexual Communication

Ethology — Tue, 03 Nov 2009 00:00:00 +0100

As major river drainages separated and stream capture occurred, some populations of Xiphophorus fishes became geographically isolated from one another, while others came into contact with new Xiphophorus species. Sexual communication and mechanisms of reproductive isolation were likely influenced by the variation in community structure each population experienced. One swordtail species, Xiphophorus birchmanni, occurs both in streams where other Xiphophorus species are rare, or more typically with large populations of congeners. Using the X. birchmanni system, we tested the theory that species recognition should be favored when the opportunity for hybridization is high. We found that at a site where the congener, X. variatus, is the predominant species, female X. birchmanni have a strong pr...

Announcement

The American Naturalist — Mon, 02 Nov 2009 19:37:28 +0100

The American Naturalist, Volume 174, Issue 6, Page iii, December 2009. (Source: The American Naturalist)

Treasurer's Report, 2008, American Society of Naturalists

The American Naturalist — Mon, 02 Nov 2009 19:28:04 +0100

The American Naturalist, Volume 174, Issue 6, Page 936, December 2009. (Source: The American Naturalist)

MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.

Secretary’s Report, 2009, American Society of Naturalists

The American Naturalist — Mon, 02 Nov 2009 19:28:00 +0100

The American Naturalist, Volume 174, Issue 6, Page 932-935, December 2009. (Source: The American Naturalist)

Mate Choice for Genetic Benefits: Time to Put the Pieces Together

Ethology — Mon, 02 Nov 2009 00:00:00 +0100

It is thought that mate choice allows individuals to obtain genetic benefits for their offspring, and although many studies have found some support for this hypothesis, several critical questions remain unresolved. One main problem is that empirical studies on mate choice and genetic benefits have been rather piecemeal. Some studies (1) aimed to test how mate choice affects offspring fitness, but have not examined whether the benefits are because of genetic effects. Other studies tested whether mate choice provides (2) additive or (3) non-additive genetic benefits and only a few studies (4) considered these genetic effects together. Finally, some studies (5) examined whether the potential benefits that might be gained from mate choice are due to additive genetic effects vs. non-additive ef...

Socio-Spatial Relationships in Dairy Cows

Ethology — Mon, 02 Nov 2009 00:00:00 +0100

Farm animals may serve as models for evaluating social networks in a controlled environment. We used an automated system to track, at fine temporal and spatial resolution (once per minute, ±50 cm) every individual in six herds of dairy cows (Bos taurus). We then analysed the data using social network analyses. Relationships were based on non-random attachment and avoidance relationships in respect to synchronous use and distances observed in three different functional areas (activity, feeding and lying). We found that neither synchrony nor distance between cows was strongly predictable among the three functional areas. The emerging social networks were tightly knit for attachment relationships and less dense for avoidance relationships. These networks loosened up from the feeding and lyin...

Age Affects Over-Marking of Opposite-Sex Scent Marks in Meadow Voles, Microtus pennsylvanicus

Ethology — Mon, 02 Nov 2009 00:00:00 +0100

Models of age-related effects on behavior predict that among short-lived species younger adults are more attractive and attracted to opposite-sex conspecifics than are older adults, whereas the converse is predicted for long-lived species. Although most studies of age-related effects on behavior support these predictions, they are not supported by many studies of scent marking, a behavior used in mate attraction. Over-marking, a form of scent marking, is a tactic used by many terrestrial mammals to convey information about themselves to opposite-sex conspecifics. The present study tested the hypothesis that the age of meadow voles, Microtus pennsylvanicus; a microtine rodent, affects their over- and scent-marking behaviors when they encounter the marks of opposite-sex conspecifics. Sex dif...

Myxobolus notropis from emerald shiner, Notropis atherinoides Rafinesque, in Lake Superior

Journal of Fish Diseases — Mon, 02 Nov 2009 00:00:00 +0100

(Source: Journal of Fish Diseases)

MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.

Appeasing pheromone inhibits cortisol augmentation and agonistic behaviors during social stress in adult miniature pigs.

Zoological Science — Sun, 01 Nov 2009 00:00:00 +0100

In this study, we Investigated the effects of PAP on social and Immune stress response In adult female miniature pigs. PAP or vehicle solvents were sprayed Into the pens of Individually housed adult sows. A two-week exposure to the pheromone did not alter basal salivary Cortisol levels or clrcadlan rhythms. Following this treatment, the animals were paired and placed In a new pen that was divided with a wire-mesh fence. Although salivary cortisol Increased markedly In the vehicle-treated group, the PAP-treated group exhibited a drastic Inhibition of cortisol secretion. This effect was sustained even after they were allowed to physically Interact following fence removal. Moreover, the latency time of agonistic behaviors, such as escaping or biting, was significantly extended after PAP expos...

Localization and Copy Number of the Protein-Coding Genes Actin, alpha-Tubulin, and HSP90 in the Nucleus of a Primitive Dinoflagellate, Oxyrrhis marina.

Zoological Science — Sun, 01 Nov 2009 00:00:00 +0100

This study is the first to locate protein-coding genes in the nucleus of a dinoflagellate, although the chromosomes were greatly damaged during the FISH process. The copy number of each gene per cell was estimated using real time PCR. Resulting copy numbers of actin, alpha-tubulin and HSP90 were, 33.7, 10.4 and 5.4, respectively. PMID: 19877833 [PubMed - in process] (Source: Zoological Science)

The Balbiani Body in the Female Germline Cells of an Earwig, Opisthocosmia silvestris.

Zoological Science — Sun, 01 Nov 2009 00:00:00 +0100

Authors: Tworzydlo W, Kloc M, Bilinski SM In the majority of invertebrate and vertebrate species, gametogenesls starts with the formation of cysts (clusters) of sibling germline cells. Cysts originate as the result of mitotic divisions of a specialized germline cell, the cystoblast. Since these divisions are incomplete, the cyst cells (cystocytes) remain connected by stable connections, termed intercellular bridges (ring canals). In forflculold earwigs, female germ cell cysts are composed of two cells only: the pro-oocte and pro-nurse cells. We show that in Opisthocosmia silvestris, the cystoblast, as well as both cells of the cyst, contain the Balbiani body (Bb), a distinct cytoplasmic organelle composed of numerous mitochondria. We also show that in the cyst cells, the Bbs are invari...

Local pharmacological effects of tungstate on the color-pattern determination of butterfly wings: a possible relationship between the eyespot and parafocal element.

Zoological Science — Sun, 01 Nov 2009 00:00:00 +0100

Authors: Dhungel B, Otaki JM Butterfly wing color patterns can be changed by the application of a temperature shock or pharmacological agents such as tungstate, producing a distinctive type of elemental modification called the TS (temperature shock) type. Heterochronic uncoupling between the signaling and reception steps during the color-pattern determination process has been proposed as a mechanism for TS-type changes. As an extension of this hypothesis, both the parafocal element (PFE) and the eyespot in the same wing compartment are considered to be determined by morphogenic signal(s) emitted from the same eyespot focus. However, these models need to be examined with additional experimental data. Furthermore, there is controversy as to whether the action of tungstate on wing color p...

Mitochondrial DNA Analysis of the Japanese Wolf (Canis lupus hodophilax Temminck, 1839) and Comparison with Representative Wolf and Domestic Dog Haplotypes.

Zoological Science — Sun, 01 Nov 2009 00:00:00 +0100

Authors: Ishiguro N, Inoshima Y, Shigehara N Mitochondrial DNA (mtDNA) D-loop control region sequences ranging In length from 583 to 598 bp were determined for eight Japanese wolf specimens (Canis lupus hodophilax Temminck, 1839) collected from several sites and compared with 105 haplotypes from the domestic dog (C. lupus familiaris) and continental grey wolf (C. lupus lupus). Also, a 197-bp mtDNA sequence was amplified from archaeological wolf specimens and two continental wolf specimens (C. lupus chanco) as reference sequences for analysis. The mtDNA haplotypes from the eight Japanese wolf specimens were closely related to each other and grouped in a single lineage with an 88% bootstrap value in a neighbor-Joining analysis. The results provide valuable Information for understanding t...

MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.

Song Control Nuclei in Male and Female Large-billed Crows (Corvus macrorhynchos).

Zoological Science — Sun, 01 Nov 2009 00:00:00 +0100

Authors: Wang R, Sun Y, Zhang X, Zeng S, Xie W, Yu Y, Zhang X, Zuo M We show that the learned vocalizations of male and female large-billed crows (Corvus macrorhynchos) are similar and that their functions and physical features show significant differences from those of other oscine species. We investigate whether the song control nuclei of crows show any sexual differences in size, reflecting differences in their singing behavior, and whether these nuclei are different from those of other songbirds in terms of neural connectivity size and relative to the forebrain. Our Nissl staining results reveal that 1) of the four song nuclei examined (HVC; the robust nucleus of the arcopallium [RA]; Area X; and the dorsolateral medial nucleus [DLM]), HVC, RA, and Area X volumes are significantly ...

Behavioral responses by migratory chum salmon to amino acids in natal stream water.

Zoological Science — Sun, 01 Nov 2009 00:00:00 +0100

This study hypothesized that amino acids found in natal stream water have a role in the ability of mature male chum salmon (Oncorhynchus keta) to home to the Osaru River (OR), Hokkaido, Japan. Behavioral experiments were conducted in a two-choice test tank using various combinations of control water (natural Toya Lake water; NLW and three artificial stream waters using amino acids: 1) artificial OR water (AOR); 2) AOR without L-glutamic acid, the major amino acid in OR water (AOR-E); and 3) artificial water matching another stream (ALS) that had much higher amino acid concentrations than OR. In behavioral tests, the fish did not select between AOR and AOR-E, but still chose AOR over NLW, AOR-E over NLW, and AOR over ALS. These results suggest that migratory male chum salmon respond to amin...

Molecular Cloning and Expression Analysis of Ovary-Specific Transcript 1 (Pm-OSTI) of the Giant Tiger Shrimp, Penaeus monodon.

Zoological Science — Sun, 01 Nov 2009 00:00:00 +0100

In this study, a transcript that significantly matched the polehole precursor was further characterized by RACE-PCR. The sequence obtained was 5151 bp in length and contained a coding region of 5031 bp corresponding to 1677 amino acids. This transcript was only expressed in ovaries but not in testes of Juveniles (N=10) and broodstock (N=22) of P. monodon. A tissue distribution analysis further confirmed ovary-specific expression of this transcript (called P. monodon ovary-specific transcript 1, Pm-OST1) in female broodstock. Expression levels of Pm-OST 1 in ovaries of juvenile P. monodon upon 5-HT Injection (33.9+/-6.40 g; 50 microg/g body weight) were significantly higher at 12-72 hours post Injection (P<0.05). Quantitative real-time PCR Indicated that Pm-OST1 was comparably expressed ...

Karyotypes of six soricomorph species from emei shan, sichuan province, china.

Zoological Science — Sun, 01 Nov 2009 00:00:00 +0100

We report the karyotypes of six species of the order Soricomorpha (Mammalia), based on specimens collected from Emei Shan (Mount Emei) in central Sichuan Province, China: two talpid species, Uropsilus andersoni (diploid chromosome number [2n]=34, fundamental number of chromosome arms Including two X chromosomes [FN]=56) and Scaptonyx fusicaudus (2n=34, FN=64); and four soricid species, Episoriculus sacratus (2n=58, FN=108), Anourosorex squamipes (2n=48, FN=96), Sorex cylindricauda (2n=30, FN=50), and Sorex bedfordiae (2n=24/25, FN=46/48). This is the first report of the karyotypes of all species except Sc. fusicaudus and A. squamipes. Episoriculus sacratus is considered to be a valid species in Sichuan, separated from the Nepalese E. soluensis based on differences in the karyotype. The kar...

New Records of the Nereidid Polychaete Leonnates persicus from Japan, Korea, and Thailand, with a Redescription of the Holotype.

Zoological Science — Sun, 01 Nov 2009 00:00:00 +0100

We describe some Important new characteristics of the holotype, which had not been appropriately described in previous literature. PMID: 19877841 [PubMed - in process] (Source: Zoological Science)

MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.

Molecular Cloning and Expression Analysis of Ovary-Specific Transcript 1 (Pm-OST1) of the Giant Tiger Shrimp, Penaeus monodon.

Zoological Science — Sun, 01 Nov 2009 00:00:00 +0100

Isometric scaling in home-range size of male and female bobcats (Lynx rufus)

Canadian Journal of Zoology — Sat, 31 Oct 2009 15:58:35 +0100

Adam W. Ferguson, Nathan A. Currit, and Floyd W. Weckerly - For solitary carnivores a polygynous mating system should lead to predictable patterns in space-use dynamics. Females should be most influenced by resource distribution and abundance,... (Source: Canadian Journal of Zoology)

Forming foci of transmission: the effects of resource utilization, species interaction, and parasitism on molluscan movement

Canadian Journal of Zoology — Sat, 31 Oct 2009 15:58:35 +0100

T. T. Gray, J. T. Detwiler, and D. J. Minchella - Animal aggregation to environmental cues provides opportunities for parasite transmission between individual hosts of the same or different species. Better characterization of host behavioral responses... (Source: Canadian Journal of Zoology)

Do territorial male three-spined sticklebacks have sperm with different characteristics than nonterritorial males?

Canadian Journal of Zoology — Fri, 30 Oct 2009 16:09:47 +0100

J. Côté, P. U. Blier, A. Caron, and F. Dufresne - The three-spined stickleback (Gasterosteus aculeatus aculeatus L., 1758) shows unequal energetic expenditure upon reproduction as some males defend territories and build nest (territorials: TM) where... (Source: Canadian Journal of Zoology)

Koi herpesvirus: distribution and prospects for control in England and Wales

Journal of Fish Diseases — Fri, 30 Oct 2009 00:00:00 +0100

This study aimed to determine the geographic distribution and prevalence of KHV exposed fish in England and Wales through ELISA antibody testing. Only three of the 82 farms sampled produced positive results, suggesting fish farms provide a relatively safe source of fish. Of the 71 'high-risk' fisheries tested, 26 were positive. All eight geographic areas within England and Wales studied had at least one KHV positive site. Twelve consignments of imported koi carp from seven S.E. Asian countries were tested for KHV antibody. Six consignments from six different countries were positive. Although a high proportion of consignments were positive, the results indicate that lower risk stocks of fish exist that could be sourced by the ornamental carp sector. The study provides evidence that KHV is w...

MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.

Tunic morphology and viral surveillance in diseased Korean ascidians: soft tunic syndrome in the edible ascidian, Halocynthia roretzi (Drasche), in aquaculture

Journal of Fish Diseases — Fri, 30 Oct 2009 00:00:00 +0100

'Soft tunic syndrome' causes mass mortality in the edible ascidian Halocynthia roretzi in Korean and Japanese aquaculture. In histopathological comparison, there were no specific differences between diseased specimens from Korea and Japan, indicating that soft tunic syndrome occurring in Korea and Japan is the same disease. No bacterial or protozoan cells were microscopically detected in either healthy or diseased tunics suggesting they are not the direct causes of soft tunic syndrome. Attempts were made to isolate virus from affected ascidians taking into account temperature conditions in which soft tunic syndrome is most prevalent in the field. However, no viruses were isolated from diseased or non-diseased specimens using chinook salmon embryo (CHSE-214), flounder fin (FFN) or epithelio...

First isolation of Tenacibaculum soleae from diseased cultured wedge sole, Dicologoglossa cuneata (Moreau), and brill, Scophthalmus rhombus (L.)

Journal of Fish Diseases — Fri, 30 Oct 2009 00:00:00 +0100

(Source: Journal of Fish Diseases)

In vitro markers for virulence in Yersinia ruckeri

Journal of Fish Diseases — Fri, 30 Oct 2009 00:00:00 +0100

In this study, different traits that have been associated with bacterial virulence were studied in Yersinia ruckeri. Two isolates that had been shown to cause disease and mortality in experimentally infected rainbow trout were compared with five avirulent isolates. Both virulent isolates showed high adhesion to gill and intestinal mucus of rainbow trout, whereas the majority of non-virulent strains demonstrated significantly lower adhesion. A decrease in adherence capability following bacterial treatment with sodium metaperiodate and proteolytic enzymes suggested the involvement of carbohydrates and proteins. All strains were able to adhere to and invade chinook salmon embryo cell line (CHSE-214), fathead minnow epithelial cell line (FHM) and rainbow trout liver cell line (R1). One non-vir...

Wnt4 is not sufficient to induce lobuloalveolar mammary development

BMC Developmental Biology - Latest articles — Fri, 30 Oct 2009 00:00:00 +0100

Conclusions: : Taken together, we propose that Wnt4 is necessary, but not sufficient, to induce side-branch development. (Source: BMC Developmental Biology - Latest articles)

Size and spacing of grouse leks: comparing capercaillie (Tetrao urogallus) and black grouse (Tetrao tetrix) in two contrasting Eurasian boreal forest landscapes

Canadian Journal of Zoology — Thu, 29 Oct 2009 16:10:36 +0100

Jørund Rolstad, Per Wegge, Andrey V. Sivkov, Olav Hjeljord, and Ken Olaf Storaunet - Capercaillie (Tetrao urogallus L., 1758) and black grouse (Tetrao tetrix L., 1758 (= Lyrurus tetrix (L., 1758))) are two sympatric Eurasian lekking grouse species that differ... (Source: Canadian Journal of Zoology)

MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.

Erratum to: Do captive mandrills invent new gestures?

Animal Cognition — Thu, 29 Oct 2009 00:00:00 +0100

Authors: Laidre ME PMID: 19865838 [PubMed - as supplied by publisher] (Source: Animal Cognition)

A heritable component in sex ratio and caste determination in a Cardiocondyla ant

Frontiers in Zoology — Wed, 28 Oct 2009 00:00:00 +0100

Studies on sex ratios in social insects provide among the most compelling evidence for the importance of kin selection in social evolution. The elegant synthesis of Fisher's sex ratio principle and Hamilton's inclusive fitness theory predicts that colony-level sex ratios vary with the colonies' social and genetic structures. Numerous empirical studies in ants, bees, and wasps have corroborated these predictions. However, the evolutionary optimization of sex ratios requires genetic variation, but one fundamental determinant of sex ratios - the propensity of female larvae to develop into young queens or workers ("queen bias") - is thought to be largely controlled by the environment. Evidence for a genetic influence on sex ratio and queen bias is as yet restricted to a few taxa, in particular...

The Influence of Perenniality and Seed Banks on Polymorphism in Plant‐Parasite Interactions

The American Naturalist — Tue, 27 Oct 2009 18:37:14 +0100

The American Naturalist, Volume 0, Issue 0, Page 000, Latest Articles. Abstract: Antagonistic interactions, such as diseases, play an important role in natural populations. Understanding the mechanisms that promote long‐term polymorphism at loci that are involved in host‐parasite recognition is a fundamental problem in evolutionary ecology. Coevolution implies the existence of indirect frequency‐dependent selection because the fitnesses of parasite genotypes depend on the frequencies of host genes and vice versa. Polymorphism can be maintained in both organisms if there is also negative, direct, frequency‐dependent selection, when natural selection for host resistance or parasite virulence declines with increasing frequency of that trait itself. In this article, using the gen...

Do Speciation Rates Drive Rates of Body Size Evolution in Mammals?

The American Naturalist — Tue, 27 Oct 2009 16:20:18 +0100

The American Naturalist, Volume 0, Issue 0, Page 000, Latest Articles. Abstract: Recently, it has been shown with large data sets of extinct mammals that large‐bodied lineages experienced higher speciation and extinction rates; with extant mammals, it has been shown that body size evolution is accelerated during speciation. Therefore, it is interesting to investigate whether mammalian body size evolution is faster in large‐bodied lineages. Phylogenetic analysis assuming size‐independent speciation rates suggested that the rate of body size evolution increases with body size, whereas size differences in recent sister species (that are little affected by species turnover) appear to be independent of size. This supports the hypothesis that high rates of species turnover increase t...

Vegetation, Fire, and Feedbacks: A Disturbance‐Mediated Model of Savannas

The American Naturalist — Tue, 27 Oct 2009 15:09:17 +0100

The American Naturalist, Volume 0, Issue 0, Page 000, Latest Articles. Abstract: Savanna models that are based on recurrent disturbances such as fire result in nonequilibrium savannas, but these models rarely incorporate vegetation feedbacks on fire frequency or include more than two states (grasses and trees). We develop a disturbance model that includes vegetation‐fire feedbacks, using a system of differential equations to represent three main components of savannas: grasses, fire‐tolerant savanna trees, and fire‐intolerant forest trees. We investigate the stability of savannas in the presence of positive feedbacks of fire frequency with (1) grasses, (2) savanna trees, and (3) grasses and savanna trees together while also allowing for negative feedbacks of forest trees on fir...

MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.

Putting the Weary Ghost of Clements to Rest: A Brief Response to Brooker et al.’s Comment

The American Naturalist — Tue, 27 Oct 2009 15:07:58 +0100

The American Naturalist, Volume 0, Issue 0, Page 000, Latest Articles. (Source: The American Naturalist)

Don’t Diss Integration: A Comment on Ricklefs’s Disintegrating Communities

The American Naturalist — Tue, 27 Oct 2009 15:01:01 +0100

The American Naturalist, Volume 0, Issue 0, Page 000, Latest Articles. Abstract: Ricklefs’s recent call to investigate ecological processes at large scales helps focus ecologists’ attention on an undoubtedly important topic. However, we believe that some of his accompanying arguments for the primacy of such work and, in particular, for the need to “disintegrate” the local community concept are flawed. We revisit Ricklefs’s main tenets and demonstrate that research on local communities is a vital part of understanding processes and diversity across a range of spatial and temporal scales. The integration of research across spatial scales expands our horizons and understanding of ecology and evolution, and this should not be unnecessarily constrained to one extreme or the othe...

Transcriptome analysis of the venom glands of the Chinese wolf spider Lycosa singoriensis.

Zoology — Tue, 27 Oct 2009 00:00:00 +0100

Authors: Zhang Y, Chen J, Tang X, Wang F, Jiang L, Xiong X, Wang M, Rong M, Liu Z, Liang S The wolf spider Lycosa singoriensis is a hunting spider with a widespread distribution in northwest China. The venom gland of spiders, which is a very specialized secretory tissue, can secrete abundant and complex toxin components. To extensively examine the transcripts expressed in the venom glands of L. singoriensis, we generated 833 expressed sequence tags (ESTs) from a directional cDNA library. Toxin-like sequences account for 69.1% of these ESTs, 17.3% are similar to cellular transcripts and 13.6% have no significant similarity to any known sequences. Here, we identified 223 novel toxin-like sequences, which can be classified into six different superfamilies; that means a novel potential sou...

Trade-off between morphological convergence and opportunistic diet behavior in fish hybrid zone

Frontiers in Zoology — Tue, 27 Oct 2009 00:00:00 +0100

Conclusions: The Durance River is an untamed Mediterranean river despite the presence of numerous dams that split the river from upstream to downstream. The sympatric effect on morphology and the large diet behavior range can be explained by a tendency toward an opportunistic behavior of the sympatric specimens. Indeed, the similar response of the two species and their hybrids implied an adaptation that could be defined as an alternative trade-off that underline the importance of epigenetics mechanisms for potential success in a novel environment. (Source: Frontiers in Zoology)

Functional Morphology of the Gill in Amazonian Freshwater Stingrays (Chondrichthyes: Potamotrygonidae): Implications for Adaptation to Freshwater

Physiological and Biochemical Zoology — Mon, 26 Oct 2009 21:09:56 +0100

Physiological and Biochemical Zoology, Volume 0, Issue 0, Page 000, Latest Articles. Abstract The gill morphologies of six species of potamotrygonid freshwater stingrays from the Amazon basin were investigated using light and electron microscopy. Some unique features were found in the potamotrygonid gill: (1) fingerlike protuberances on the gill filament, (2) an Alcian blue/periodic acid–Schiff–positive histochemical reaction for several cell layers in the gill epithelium (except the basal ones), (3) pavement cells with numerous subapical mucous vesicles, (4) very large mucous cells, and (5) follicular Na+/K+‐ATPase‐rich (NKA‐rich) mitochondria‐rich cells (MRCs) in Potamotrygon sp. (known as the cururu ray). The fingerlike protuberances may constitute an additional resist...

MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.

Island Species Richness Increases with Habitat Diversity

The American Naturalist — Mon, 26 Oct 2009 20:24:43 +0100

The American Naturalist, Volume 0, Issue 0, Page 000, Latest Articles. Abstract: Species richness is commonly thought to increase with habitat diversity. However, a recent theoretical model aiming to unify niche and island biogeography theories predicted a hump‐shaped relationship between richness and habitat diversity. Given the contradiction between model results and previous knowledge, we examine whether the relationship between species richness and habitat diversity is consistently monotonically increasing and under which circumstances, if at all, such relationships could be hump shaped. We review the empirical evidence about the shape of such relationships and show that species richness on islands usually increases with habitat diversity and that it never decreases. We also cr...

No evidence of expression of two classes of natural antibiotics (cathelicidins and defensins) in a sample of platypus milk

Australian Journal of Zoology — Sun, 25 Oct 2009 14:00:59 +0100

Camilla M. Whittington, Julie A. Sharp, Anthony Papenfuss, Katherine Belov - Volume 57(4) (Source: Australian Journal of Zoology)

A review of mucormycosis in the platypus (Ornithorhynchus anatinus)

Australian Journal of Zoology — Sun, 25 Oct 2009 14:00:58 +0100

Joanne H. Connolly - Volume 57(4) (Source: Australian Journal of Zoology)

Activity and behaviour of lactating echidnas (Tachyglossus aculeatus multiaculeatus) from hatching of egg to weaning of young

Australian Journal of Zoology — Sun, 25 Oct 2009 14:00:57 +0100

Peggy D. Rismiller, Michael W. McKelvey - Volume 57(4) (Source: Australian Journal of Zoology)

Monotreme chromosomes: an introductory review

Australian Journal of Zoology — Sun, 25 Oct 2009 14:00:56 +0100

Carolyn E. Murtagh, G. B. Sharman - Volume 57(4) (Source: Australian Journal of Zoology)

MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.

Hatching time for monotreme immunology

Australian Journal of Zoology — Sun, 25 Oct 2009 14:00:55 +0100

Emily S. W. Wong, Anthony T. Papenfuss, Robert D. Miller, Katherine Belov - Volume 57(4) (Source: Australian Journal of Zoology)

Evolutionary and phylogenetic significance of platypus microsatellites conserved in mammalian and other vertebrate genomes

Australian Journal of Zoology — Sun, 25 Oct 2009 14:00:54 +0100

E. Buschiazzo, N. J. Gemmell - Volume 57(4) (Source: Australian Journal of Zoology)

The enigma of the platypus genome

Australian Journal of Zoology — Sun, 25 Oct 2009 14:00:53 +0100

Wesley C. Warren, Frank Grützner - Volume 57(4) (Source: Australian Journal of Zoology)

Do genomic datasets resolve the correct relationship among the placental, marsupial and monotreme lineages?

Australian Journal of Zoology — Sun, 25 Oct 2009 14:00:52 +0100

Gavin Huttley - Volume 57(4) (Source: Australian Journal of Zoology)

Platypus venom genes expressed in non-venom tissues

Australian Journal of Zoology — Sun, 25 Oct 2009 14:00:51 +0100

Camilla M. Whittington, Katherine Belov - Volume 57(4) (Source: Australian Journal of Zoology)

MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.

Breeding behaviour of the platypus (Ornithorhynchus anatinus) in captivity

Australian Journal of Zoology — Sun, 25 Oct 2009 14:00:50 +0100

Margaret Hawkins, Adam Battaglia - Volume 57(4) (Source: Australian Journal of Zoology)

Reproductive strategies of the short-beaked echidna – a review with new data from a long-term study on the Tasmanian subspecies (Tachyglossus aculeatus setosus)

Australian Journal of Zoology — Sun, 25 Oct 2009 14:00:49 +0100

Gemma Morrow, Niels A. Andersen, Stewart C. Nicol - Volume 57(4) (Source: Australian Journal of Zoology)

Thermoregulation in monotremes: riddles in a mosaic

Australian Journal of Zoology — Sun, 25 Oct 2009 14:00:48 +0100

Peter H. Brice - Volume 57(4) (Source: Australian Journal of Zoology)

Distribution, prevalence and persistence of mucormycosis in Tasmanian platypuses (Ornithorhynchus anatinus)

Australian Journal of Zoology — Sun, 25 Oct 2009 14:00:47 +0100

Nick Gust, Joshua Griffiths, Michael Driessen, Annie Philips, Niall Stewart, Dominic Geraghty - Volume 57(4) (Source: Australian Journal of Zoology)

Population genetics of the platypus (Ornithorhynchus anatinus): a fine-scale look at adjacent river systems

Australian Journal of Zoology — Sun, 25 Oct 2009 14:00:46 +0100

Stephen H. Kolomyjec, Josephine Y. T. Chong, David Blair, Jaime Gongora, Tom R. Grant, Christopher N. Johnson, Chris Moran - Volume 57(4) (Source: Australian Journal of Zoology)

MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.

Development of microsatellite markers for the short-beaked echidna using three different approaches

Australian Journal of Zoology — Sun, 25 Oct 2009 14:00:45 +0100

C. Vanpé, E. Buschiazzo, J. Abdelkrim, G. Morrow, S. C. Nicol, N. J. Gemmell - Volume 57(4) (Source: Australian Journal of Zoology)

Platypus venom: source of novel compounds

Australian Journal of Zoology — Sun, 25 Oct 2009 14:00:44 +0100

Jennifer M. S. Koh, Paramjit S. Bansal, Allan M. Torres, Philip W. Kuchel - Volume 57(4) (Source: Australian Journal of Zoology)

Effects of feeding level of milk replacer on body growth, plasma metabolite and insulin concentrations, and visceral organ growth of suckling calves

Animal Science Journal — Fri, 23 Oct 2009 23:00:00 +0100

The objective was to evaluate effects of feeding level of milk replacer on body growth, plasma metabolite and insulin concentrations, and allometric growth of visceral organs in suckling calves. Holstein bull calves (n = 8; 3[ndash]4 days of age) were fed either a low amount (average 0.63 kgDM/day, LM) or high amount (average 1.15 kgDM/day, HM) of high protein milk replacer until they were slaughtered at 6 weeks of age. Body weight (BW) at 4, 5, and 6 weeks of age, feed intake, average daily gain, and feed efficiency were higher in the HM than LM calves. The HM group had higher plasma glucose at 3 and 4 weeks of age and insulin levels after the age of 4 weeks compared with LM calves whereas no effect was detected on plasma nonesterified fatty acid or urea nitrogen concentrations. The HM ca...

Inverse‐Gene‐for‐Gene Infection Genetics and Coevolutionary Dynamics

The American Naturalist — Fri, 23 Oct 2009 17:21:47 +0100

We present an alternative model, termed inverse‐gene‐for‐gene (IGFG), where pathogen infectiousness is determined by parasite recognition of host signals and/or receptors or where there is active host searching by parasites. We show that coevolutionary dynamics under IGFG are both qualitatively and quantitatively different from those of the GFG model, and we suggest that this new approach may be applicable to a range of important host‐parasite systems that are not currently catered for by the existing frameworks. (Source: The American Naturalist)

Selection, Epistasis, and Parent‐of‐Origin Effects on Deleterious Mutations across Environments in Drosophila melanogaster

The American Naturalist — Fri, 23 Oct 2009 16:19:58 +0100

The American Naturalist, Volume 0, Issue 0, Page 000, Latest Articles. Abstract: Understanding the nature of selection against deleterious alleles is central to determining how populations are affected by the constant influx of new mutations. Important progress has been made in estimating basic attributes of the distribution of selection coefficients and gene interaction effects (epistasis). Although most aspects of selection are likely to be context dependent, little is known about the effect of stress on selection and epistasis at the level of individual genes, especially in multicellular organisms. Using Drosophila melanogaster, we measure how selection on 20 mutant alleles is affected by direct and indirect genetic factors across two environments. We find that environmental stres...

MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.

Effect of elemental nano-selenium on semen quality, glutathione peroxidase activity, and testis ultrastructure in male Boer goats.

Animal Reproduction Science — Fri, 23 Oct 2009 00:00:00 +0100

In conclusion, selenium deficiency resulted in abnormal spermatozoal mitochondria, and supplementation with nano-Se enhanced the testis Se content, testicular and semen GSH-Px activity, protected the membrane system integrity and the tight arrayment of the midpiece of the mitochondria. Further studies are required to research the novel elemental nano-Se with characterization of bioavailability and toxicity in small ruminants. PMID: 19914014 [PubMed - as supplied by publisher] (Source: Animal Reproduction Science)

Analysis of consumers' preferences and behavior with regard to horse meat using a structured survey questionnaire

Animal Science Journal — Thu, 22 Oct 2009 23:00:00 +0100

In this study, a structured survey questionnaire was used to determine consumers' preferences and behavior with regard to horse meat at a horse meat restaurant located in Jeju, Korea, from October 1 to December 24, 2005. The questionnaire employed in this study consisted of 20 questions designed to characterize six general attributes: horse meat sensory property, physical appearance, health condition, origin, price, and other attributes. Of the 1370 questionnaires distributed, 1126 completed questionnaires were retained based on the completeness of the answers, representing an 82.2% response rate. Two issues were investigated that might facilitate the search for ways to improve horse meat production and marketing programs in Korea. The first step was to determine certain important factors,...

Oscillating magnetic field disrupts magnetic orientation in Zebra finches, Taeniopygia guttata

Frontiers in Zoology — Thu, 22 Oct 2009 23:00:00 +0100

Conclusions: The results indicate that zebra finches use a receptor that bases on radical pair prozesses for sensing the direction of the earth magnetic field in this short distance orientation behavior. (Source: Frontiers in Zoology)

Ecological Opportunity in Adaptive Radiation of Galápagos Endemic Land Snails

The American Naturalist — Thu, 22 Oct 2009 17:15:21 +0100

The American Naturalist, Volume 0, Issue 0, Page 000, Latest Articles. Abstract: The classic evolutionary hypothesis of ecological opportunity proposes that both heterogeneity of resources and freedom from enemies promote phenotypic divergence as a response to increased niche availability. Although phenotypic divergence and speciation have often been inferred to be the primary consequences of the release from competition or predation that accompanies a shift to a new adaptive zone, increased phenotypic variation within species is expected to represent the first stage resulting from such a shift. Using measures of intraspecific morphological variation of 30 species of Galápagos endemic land snails in a phylogenetically controlled framework, we show that the number of local congeners ...

Flight initiation distance is differentially sensitive to the costs of staying and leaving food patches in a small-mammal prey

Canadian Journal of Zoology — Thu, 22 Oct 2009 15:31:17 +0100

Patricio A. Lagos, Andrea Meier, Liliana Ortiz Tolhuysen, Rodrigo A. Castro, Francisco Bozinovic, and Luis A. Ebensperger - Escape theory predicts that a prey should flee from an approaching predator at a point in which the cost of staying equals the cost of... (Source: Canadian Journal of Zoology)

MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.

Eye movements during list execution reveal no planning in monkeys (Macaca fascicularis).

Journal of Experimental Psychology: Animal Behavior Processes — Thu, 22 Oct 2009 15:31:00 +0100

When trained on a serial-order task to respond to 5 simultaneously displayed stimuli, monkeys (Macaca fascicularis) show an elevated latency to respond to the first item (A) or the first 2 items (A and B) followed by short and uniform latencies to respond to the remaining items. This pattern has been interpreted as evidence of planning, with the long initial latency reflecting the animal planning their responses, and the subsequent short and uniform latencies reflecting the execution of the planned responses. An analysis of eye movements, however, revealed no evidence of planning. The elevated latency to item A is likely an artifact of the method of stimulus display. (PsycINFO Database Record (c) 2009 APA, all rights reserved) (Source: Journal of Experimental Psychology: Animal Behavior Pr...

“Causal reasoning” in rats: A reappraisal.

Journal of Experimental Psychology: Animal Behavior Processes — Thu, 22 Oct 2009 15:31:00 +0100

It has recently been argued that rats engage in causal reasoning and they do so in a way that is consistent with Bayes net theories (Blaisdell, Sawa, Leising & Waldmann, 2006). This argument was based upon the finding that the tendency of cues to elicit approach to a food-well was reduced when their presentation was contingent on lever pressing. There is, however, an alternative interpretation of the critical experimental findings that is based on the simple principle of response competition: wherein lever pressing interferes with the tendency to approach the food well. Here the authors replicated Experiments 1 and 2a of Blaisdell et al. (2006) and found reciprocal patterns of lever pressing and food well approach during the critical cues. These results lend direct support for an interpret...

Conditioned inhibition in the spatial domain.

Journal of Experimental Psychology: Animal Behavior Processes — Thu, 22 Oct 2009 15:30:59 +0100

Using a variation on the standard procedure of conditioned inhibition (Trials A+ and AX-), rats (Rattus norvegicus) in a circular pool were trained to find a hidden platform that was located in a specific spatial position in relation to 2 individual landmarks (Trials A ? platform and B ? platform; Experiments 1a and 1b) and to 2 configurations of landmarks (Trials ABC ? platform and FGH ? platform; Experiment 2a). The rats also underwent inhibitory trials (Experiment 1: Trials AZ ? no platform; Experiment 2a: Trials CDE ? no platform) interspersed with these excitatory trials. In both experiments, subsequent test trials without the platform showed both a summation effect and retardation of excitatory conditioning, and in Experiment 2a rats learned to avoid the CDE quadrant over the course ...

Discrimination and generalization along a simple dimension: Peak shift and rule-governed responding.

Journal of Experimental Psychology: Animal Behavior Processes — Thu, 22 Oct 2009 15:30:59 +0100

In 2 experiments, participants learned to discriminate between a pair of simply related, but very similar, colors in a 2-choice categorization task. They were then tested over a wider range of isoluminant hues. Over these test values, both experiments yielded a postdiscrimination gradient that was initially peak-shifted but became monotonic through the course of testing. In Experiment 2, the presence of this early peak shift and subsequent change in gradient form were related to participants’ inability to verbally characterize the difference between the training stimuli. This suggests a transition from generalization based on simple physical similarity to generalization based on a “verbalizable” rule, as a consequence of additional relevant information becoming available during test....

Human sequence learning under incidental and intentional conditions.

Journal of Experimental Psychology: Animal Behavior Processes — Thu, 22 Oct 2009 15:30:59 +0100

This research explored the role that dissociable associative learning and hypothesis-testing processes may play in human sequence learning. Two 2-choice serial reaction time (SRT) tasks were conducted, 1 under incidental conditions and the other under intentional conditions. In both cases an experimental group was trained on 4 subsequences (i.e., XXX, XYY, YYX, and YXY). To control for sequential effects, sequence learning was assayed by comparing their performance to a control group that had been trained on a pseudorandom ordering, during a test phase in which both groups experienced effectively the same trial order. Under incidental conditions participants demonstrated learning of the subsequences that ended in an alternation, but not of those that ended in a repetition. In contrast, und...

MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.

Stimulus dynamics and temporal discrimination: Implications for pacemakers.

Journal of Experimental Psychology: Animal Behavior Processes — Thu, 22 Oct 2009 15:30:59 +0100

The purpose of the present study was to observe the functional relationship between stimulus dynamics and stimulus duration judgments in humans. Stimulus duration was defined as the length of time that a spinning sphere appeared on a computer screen. Stimulus dynamics were defined by how quickly the sphere rotated on its y-axis. Using a logarithmic scale, a psychophysical bisection task was used to divide stimulus durations into two categories, short and long. Across three experiments, participants’ duration judgments were longer the faster the sphere was rotated. This effect was observed over both a long and short temporal scale and over a wide range of stimulus dynamics despite the fact that the reinforcement contingencies penalized participants for this effect. The results are discuss...

Perception of food amounts by chimpanzees (Pan troglodytes): The role of magnitude, contiguity, and wholeness.

Journal of Experimental Psychology: Animal Behavior Processes — Thu, 22 Oct 2009 15:30:59 +0100

The authors investigated choice behavior by chimpanzees in five experiments involving choices between different amounts of food. Chimpanzees did not maximize the amount of food they obtained when choosing between a single 20-g banana piece and another option containing a 20-g piece and a 5-g piece. This was true even though they successfully discriminated between 20-g and 25-g banana pieces in other trials. When items in the mixed option were stacked, however, the chimpanzees chose the larger amount. Later experiments indicated that changing the magnitude of the two amounts did not change performance if the difference in magnitude between the two options remained the same (e.g., 40 g plus 10 g vs. 40 g). However, chimpanzees did improve when the two-item option was increased in its magnitu...

Contextual modulation of stimulus generalization in rats.

Journal of Experimental Psychology: Animal Behavior Processes — Thu, 22 Oct 2009 15:30:59 +0100

One connectionist analysis of the acquired equivalence/distinctiveness of cues assumes that when similar compounds (e.g., AX and BX) are paired with the same outcome (e.g., food, +; or no food, -), their components come to activate the same configural unit (ABX). When these compounds are paired with different outcomes, their components will come to address different units. Here, rats received appetitive training with eight compounds (e.g., AX+, BX+, CX-, DX-, AY+, BY-, CY-, DY+) that should generate the following configural units: ABX, CDX, ADY, and BCY. In Experiment 1, rats then received aversive conditioning to A, which should activate and revalue representations ABX and ADY. Subsequently, compounds that provided dual activation (i.e., BX and DY) of one of the revalued configural units ...

Protection from latent inhibition provided by a conditioned inhibitor.

Journal of Experimental Psychology: Animal Behavior Processes — Thu, 22 Oct 2009 15:30:59 +0100

Two conditioned suppression experiments with rats investigated the influence on latent inhibition of compounding a Pavlovian conditioned inhibitor with the target cue during preexposure treatment. Results were compared with those of subjects that received conventional latent inhibition training, no preexposure, or preexposure to the target cue in compound with a neutral stimulus. In Experiment 1, greater attenuation of the latent inhibition effect was observed in subjects that received target preexposure in compound with a Pavlovian conditioned inhibitor relative to subjects that received preexposure with a neutral stimulus or to the target alone. In Experiment 2, this protection from latent inhibition was attenuated if the excitor that was used to train the conditioned inhibitor was extin...

Enhancement of responding to A after A+/AX+ training: Challenges for a comparator theory of learning.

Journal of Experimental Psychology: Animal Behavior Processes — Thu, 22 Oct 2009 15:30:59 +0100

Two appetitive Pavlovian conditioning experiments with rats investigated the associative changes that A undergoes in an A+/AX+ blocking procedure. Conditioned responding to A was enhanced relative to stimulus B, which had been conditioned in isolation (B+). This result was interpreted in terms of the formation of a within-compound association between A and X. The results of Experiment 2 supported this conclusion by demonstrating that X had associative strength of its own and, furthermore, that extinguishing X resulted in a similar level of responding to A and B. These results are considered in terms of retrospective revaluation theories of learning. (PsycINFO Database Record (c) 2009 APA, all rights reserved) (Source: Journal of Experimental Psychology: Animal Behavior Processes)

MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.

Failure of retrospective revaluation to influence blocking.

Journal of Experimental Psychology: Animal Behavior Processes — Thu, 22 Oct 2009 15:30:59 +0100

In the blocking paradigm, subjects receive reinforced presentations of a compound, AX, after reinforced presentations of A alone. Following this training, responding to X is often diminished relative to a control group, which did not receive the prior training with A. Standard associative theories of learning such as the Rescorla–Wagner model (Rescorla & Wagner, 1972) explain this effect by assuming that A and X compete for control over behavior. In contrast, theories such as the comparator hypothesis assume that learning about X is unaffected by the properties of A, but it is the expression of this learning at test that is affected by the blocking manipulation. The aim of the 3 reported experiments was to distinguish between these 2 accounts. According to the comparator hypothesis, deva...

The dynamics of conditioning and extinction.

Journal of Experimental Psychology: Animal Behavior Processes — Thu, 22 Oct 2009 15:30:59 +0100

Pigeons responded to intermittently reinforced classical conditioning trials with erratic bouts of responding to the conditioned stimulus. Responding depended on whether the prior trial contained a peck, food, or both. A linear persistence–learning model moved pigeons into and out of a response state, and a Weibull distribution for number of within-trial responses governed in-state pecking. Variations of trial and intertrial durations caused correlated changes in rate and probability of responding and in model parameters. A novel prediction—in the protracted absence of food, response rates can plateau above zero—was validated. The model predicted smooth acquisition functions when instantiated with the probability of food but a more accurate jagged learning curve when instantiated wit...

Smad4-dependent pathways control basement membrane deposition and endodermal cell migration at early stages of mouse development

BMC Developmental Biology - Latest articles — Wed, 21 Oct 2009 23:00:00 +0100

Conclusions: Smad4 functional loss results in a dramatic shift in gene expression patterns and in the endodermal cell lineage causes an excess deposition of, or an inability to breakdown and remodel, the underlying BM layer. These structural abnormalities probably disrupt reciprocal signalling between the epiblast and overlying visceral endoderm required for gastrulation. (Source: BMC Developmental Biology - Latest articles)

Embryo development of porcine oocytes after injection with miniature pig sperm and their extracts

Animal Science Journal — Tue, 20 Oct 2009 23:00:00 +0100

This study examined embryo development of porcine oocytes after microinjection of sperm extracts (SE) in porcine intracytoplasmic sperm injection (ICSI). SE was prepared from miniature pig sperm by a nonionic surfactant, and various concentrations (0.02, 0.04 and 0.08 mg/mL) of SE were injected into the matured oocytes with a first polar body. In the pronuclear stage, the rate of oocytes with two pronuclei and a second polar body (21.4%) in the sperm and SE (0.04 mg/mL) injection group was significantly higher (P < 0.05) compared to other groups. The rate of 2[ndash]4-cell stage in sperm and SE (0.04 mg/mL) injection group was 38.1%, and it was significantly higher than that in the sperm injection group (22.9%). The rate of blastocyst stage in sperm and SE (0.04 mg/mL) injection group was ...

Duration of estrus induced after GnRH-PGF2α protocol in dairy heifer

Animal Science Journal — Tue, 20 Oct 2009 23:00:00 +0100

Estrous expressions in dairy cows have been shortened and weakened. Dairy heifers, on the other hand, may not have had such changes in estrous signs as observed in cows, since they have less stresses than cows. The aim of this study was to describe the duration of estrus in a herd of dairy heifers. A total of 56 Holstein Friesian heifers estrus was synchronized using two different hormonal protocols. They were checked for primary and secondary estrous signs with the help of heat detection devices for 48 h at an interval of 4 h starting at 16.00 hour, one day after PGF2[alpha] treatment. Onset and end of standing estrus during 48 h observation period was recorded in 35 of the 44 heifers coming into estrus within 5 days after PGF2[alpha] treatment during the observation period. The duration ...

MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.

Relationship between the lactation curve and udder disease incidence in different lactation stages in first-lactation Holstein cows

Animal Science Journal — Tue, 20 Oct 2009 23:00:00 +0100

We examined the relationships between the shape of the first parity lactation curve and udder disease incidence at different stages of lactation in 538 Holstein cows. Data used were first-parity daily milk yields and treatment records. Each cow was classified according to whether or not it had had udder disease at least once over the whole lactation period or in one of three stages within the lactation period. We then examined the differences in the shapes of the lactation curves between the disease incidence and non-incidence group in each stage. Cows that had high rates of increase in milk yield and high milk yields in early lactation were predisposed to udder disease afterwards. Cows with high milk production over a long period but with low lactation persistency were predisposed to udde...

Reproductive Value and the Stochastic Demography of Age‐Structured Populations

The American Naturalist — Tue, 20 Oct 2009 19:41:58 +0100

The American Naturalist, Volume 0, Issue 0, Page 000, Latest Articles. Abstract: The dynamics of an age‐structured population in a fluctuating environment is determined by the stochastic individual contributions from annual survival and fecundity to the total reproductive value of the population the next year. All parameters required to describe the population dynamics are simple properties of the distribution of these individual demographic contributions, which we call individual reproductive value. The asymptotic population growth rate in the average environment and the demographic and environmental variances are respectively the mean individual reproductive value over individuals through time and the variance within and between years. Our approach leads to an intuitive understan...

Behavioral avoidance of injured conspecific and predatory chemical stimuli by larvae of the aquatic caddisfly Hesperophylax occidentalis

Canadian Journal of Zoology — Tue, 20 Oct 2009 15:30:12 +0100

B. G. Gall and E. D. Brodie, Jr. - Prey animals often encounter situations that hinder their ability to conduct normal fitness-enhancing behaviors. Mating and foraging are frequently interrupted by predator vigilance and avoidance,... (Source: Canadian Journal of Zoology)

Independence of Sexual and Anti-Predator Perceptual Functions in an Acoustic Moth: Implications for the Receiver Bias Mechanism in Signal Evolution

Ethology — Mon, 19 Oct 2009 23:00:00 +0100

The receiver bias model for the evolution of mating signals proposes that selection favors male displays that happen to stimulate a general, ancestral perception in females such that receptivity and successful courtship increase. If these male signals do arise, however, the female perception will operate in two contexts, the original, typically non-sexual, one and courtship. We may then ask whether these two functions represent the same or distinct traits, which may be under separate neural and genetic control. We studied this question in Achroia grisella, a pyralid moth species in which males attract females, with an ultrasonic mating song. Hearing in pyralid moths is widespread and originated in an anti-predator context [ndash] the perception and avoidance of echolocating bats [ndash] an...

A critical review of ontogenetic development in Terebellidae (Polychaeta)

Acta Zoologica — Mon, 19 Oct 2009 23:00:00 +0100

This study reviews the ontogenetic variability of the head, the first segments and the uncini in Terebellidae, based on primary literature and development series of four terebellid species. We test hypotheses on character homologies and indicate informative characters for future phylogenetic analyses. The prostomium, identified as the region above the prototroch band of the larva, in addition to being the region of origin of the buccal tentacles, contains a series of nerves originating from the cerebrum. The peristomium, which contains the mouth, is innervated by the stomogastric nerve and consists of upper and lower lips and an internal pharynx. The loss of the first notochaetae and neurochaetae in the course of development is a recurrent pattern in terebellids. The claviform chaetae disa...

MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.

Comparative folliculogenesis and spermatogenesis of four teleost fish from a Reservoir in south-eastern Brazil

Acta Zoologica — Mon, 19 Oct 2009 23:00:00 +0100

This study provides a comparative analysis of gametogenesis of neotropical teleosts Metynnis maculatus, Megalancistrus parananus, Cichla kelberi and Satanoperca pappaterra, through histological, histochemical and histometric techniques. In the ooplasm of C. kelberi and S. pappaterra conspicuous lipid vesicles were observed, which are characteristic of pelagic eggs produced by marine fishes. Perinucleolar oocytes were identified in the testis of S. pappaterra suggesting that this species is protogynous without functional hermaphroditism, an unusual pattern for neotropical fresh-water fishes. The spermatozoa of the studied species have rounded heads, a characteristic of fish that externally fertilise their eggs. The follicular (granulosa) cells of the vitellogenic oocytes from the studied sp...

Ras promotes cell survival by antagonizing both JNK and Hid signals in the Drosophila eye

BMC Developmental Biology - Latest articles — Mon, 19 Oct 2009 23:00:00 +0100

Conclusions: In the Drosophila eye, Ras may protect cells from apoptosis by inhibiting both JNK and Hid activities. Surprisingly, reducing Ras activity in the wing, however, does not cause apoptosis but rather affects cell and organ size. Thus, in addition to its requirement for cell viability, Ras appears to mediate different biological roles depending on the developmental context and on the level of its expression. (Source: BMC Developmental Biology - Latest articles)

Bourgeois queens and high stakes games in the ant Aphaenogaster senilis

Frontiers in Zoology — Sun, 18 Oct 2009 23:00:00 +0100

Conclusions: Aggression is probably ritualised and contests are decided by workers based on relative queen fertility. First-born queens thus have an inherent advantage over second-born queens as they have longer to develop ovaries. Subordinates never retaliated against aggression from dominants and this lack of retaliation can be interpreted as a form of bourgeois strategy as dominants were almost always first-born. However, the lack of alternative reproductive options makes not-fighting effectively a form of suicide. High relatedness between full-sister queens means that subordinates may be better off sacrificing themselves than risking injury to both queens by fighting. (Source: Frontiers in Zoology)

Foods and nutritional components of diets of black bear in Rocky Mountain National Park, Colorado

Canadian Journal of Zoology — Thu, 15 Oct 2009 15:19:30 +0100

Roger A. Baldwin and Louis C. Bender - We used scat analysis to determine diets and relative nutritional values of diets for black bears (Ursus americanus Pallas, 1780) in Rocky Mountain National Park,... (Source: Canadian Journal of Zoology)