| high corticosteroid levels in plasma of adult and foetal weddell seals (leptonychotes weddelli). | pregnant and non-pregnant weddell seals and foetuses were found to have very high plasma concentrations of corticosteroids (1--7 mumol/l) that were unaffected by stress. cortisol comprised most of the corticosteroid in the adult but only 50% of that in the foetus. the affinity constant (4.30-5.53 x 10(7) l/mol) and specificity of cbg and the mcr (4.5 l/d/kg lean body mass) in adult seals were similar to those of man. the binding capacity of cbg (1.48--1.86 mumol/l) which is approximately three t ... | 1979 | 433520 |
| some anatomical aspects of the cardiovascular system of antarctic seals and their possible functional significance in diving. | the hearts and ascending aortae of 11 weddell seals, leptonychotes weddelli, three adult crabeater seals, lobodon carcinophagus, two adult ross seals, ommatophoca rossi, and one adult leopard seal, hydrurga leptonyx, were examined for comparison with terrestrial forms. the weddell seal specimens were from animals ranging in age from midterm in fetal development to mature adults. all specimens were collected in 1971, 1972, and 1973, from mcmurdo sound and the ross sea, antarctica. the phocid hear ... | 1975 | 1111424 |
| herpesvirus infections in seals: a summary of present knowledge. | this review summarises the occurrence of herpesvirus infections in pinnipeds and data from investigations carried out by the authors. these data demonstrate that herpesvirus isolates collected from harbour seals (phoca vitulina linnaeus, 1758) during the 1988 seal epidemic were almost indistinguishable from feline herpesvirus 1 and that antarctic weddell's seals (leptonychotes weddelli lesson, 1826) carry antibodies against seal herpesvirus from the north-western europe seal epidemic. the signif ... | 1992 | 1339068 |
| basic biochemical data on blood from antarctic weddell seals (leptonychotes weddelli): ions, lipids, enzymes, serum proteins and thyroid hormones. | 1. standard laboratory values of blood samples taken from weddell seals in antarctica were determined. 2. numerous blood parameters are similar to those observed in man. 3. comparatively high cholesterol levels but normal triglyceride levels were observed when compared with humans. 4. in comparison to laboratory findings in humans, t4 levels were decreased although t3 levels were normal. 5. the levels of alkaline phosphatase are considerably higher than those in humans. 6. the data obtained indi ... | 1992 | 1359937 |
| antarctic seals carry antibodies against seal herpesvirus. | weddell seals in the antarctica had high neutralizing antibody titres to seal- and feline herpesvirus and none against phocine distemper virus. crab-eater seals were free of antibodies. this suggests an evolutionary wide spread of seal herpesvirus. | 1992 | 1562238 |
| splenic contraction during breath-hold diving in the korean ama. | major increases of hemoglobin concentration and hematocrit, possibly secondary to splenic contraction, have been noted during diving in the weddell seal. we sought to learn whether this component of the diving response could be present in professional human breath-hold divers. splenic size was measured ultrasonically before and after repetitive breath-hold dives to approximately 6-m depth in ten korean ama (diving women) and in three japanese male divers who did not routinely practice breath-hol ... | 1990 | 2246181 |
| temperature and the oxygen-hemoglobin dissociation curve of the harbor seal, phoca vitulina. | to determine the effect of temperature and ph on oxygen-hemoglobin affinity of the harbor seal, we measured 61 biotonometric oxygen-hemoglobin dissociation curves on blood from 5 seals at 3 temperatures and a range of ph values. the average (+/- sem) hemoglobin concentration was 3.44 +/- 0.15 mm, nearly 50% greater than found in normal humans. at ph 7.4 the p50 (partial pressure of o2 at 50% hemoglobin saturation) +/- sem values were 22.4 +/- 0.6,25.3 +/- 0.5, and 28.5 +/- 0.4 torr at 33, 37 and ... | 1990 | 2336490 |
| carnivora: the primary structure of weddell seal (leptonychotes weddelli, pinnipedia) hemoglobin. | the hemoglobin of weddell seal (leptonychotes weddelli, pinnipedia) comprises two components with identical beta-chains. the alpha-chains differ in positions 15 (gly/asp) and 57 (ala/thr). we present the primary structure of the chains which have been separated by reversed-phase high-performance liquid chromatography. the sequences have been determined by automatic edman-degradation with the film-technique or the gas-phase method, using the native chains and the tryptic peptides of the oxidized ... | 1989 | 2775492 |
| vitamin d metabolism in polar vertebrates. | 1. studies of serum 25-hydroxy-vitamin d (25-ohd) in the antarctic have been undertaken in husky dog, seal and penguin and compared to man. 2. husky dogs showed a reversal of the expected seasonal variation of serum 25-ohd with maxima in june when the hours of bright sunshine and amount of u.v. -b radiation were lowest. 3. values for random serum 25-ohd values in seals showed large interspecies differences, the values for weddell seals being significantly greater than for crabeater seals (p less ... | 1988 | 3233926 |
| histological, histochemical, and fine structural observations on the spleen of seals. | spleens of three species of antarctic seals with different diving habits (weddell seal, crabeater seal, and fur seal) have been studied with histological, histochemical, and electron microscopic methods. the spleens can be classified as nonsinusoidal, with capsule and trabeculae rich in innervated smooth muscle cells. the trabecular system is particularly well developed in the deep- and long-diving weddell seal. as in other mammals the pulp can be divided into white and red pulp. in the white pu ... | 1987 | 3661458 |
| alpha-glycerophosphate dehydrogenase and glucose-6-phosphate dehydrogenase in tissues of the weddell seal. | high activity of alpha-glycerophosphate dehydrogenase and low activity of glucose-6-phosphate dehydrogenase in adipose tissue of weddell seals suggest that neutral fat may be assembled there from exogenous sources of fatty acids. low activity of glucose-6-phosphate dehydrogenase in other tissues tested precludes assignment of the function of fatty-acid synthesis to any specific tissue and emphasizes uniqueness of adipose mass in seals. | 1967 | 4381321 |
| the in vitro investigation of four radioactive corticosteroids in the antarctic seal (leptonychotes weddellii). | | 1974 | 4814733 |
| circulatory responses to asphyxia in pregnant and fetal animals: a comparative study of weddell seals and sheep. | | 1969 | 5371162 |
| positional distribution of fatty acids in triglycerides from milk of several species of mammals. | milk triglycerides from the echidna, koala, tammar wallaby, guinea pig, dog, cat, weddell seal, horse, pig and cow were subjected to fatty acid and stereospecific analysis to determine the positional distribution of the fatty acids in the triglycerides. the samples presented a wide range of fatty acids, most of which varied in content among species. the compositions of the acids at the 3 positions also varied among species, reflecting the content of these acids in the triglycerides. however, the ... | 1982 | 7109856 |
| the mammary gland of the weddell seal, leptonychotes weddelli (pinnipedia). i. gross and microscopic anatomy. | the weddell seal cow possesses two subcutaneous, ellipsoidal, abdominal mammary glands with a volume of two to three liters when lactating. corrosion casts reveal that approximately ten large ducts radiate from a gland cistern at the base of the nipple, and end in a complex system of terminal branches. each gland has a separate arterial supply, mostly from the caudal deep epigastric with a minor contribution from the deep circumflex iliac. histologically, lactating, nonlactating (resting), and i ... | 1981 | 7196703 |
| histological, histochemical, and ultrastructural investigations on the gastrointestinal system of antarctic seals: weddell seal (leptonychotes weddellii) and crabeater seal (lobodon carcinophagus). | the morphology of the principal sections of the gastrointestinal system of two antarctic seals with different dietary habits, namely, the weddell seal (leptonychotes weddellii) and the crabeater seal (lobodon carcinophagus), has been investigated. histologically examined by light microscopy, the tissue layers of the gastrointestinal tract of both seals are almost identical to those observed in most other mammals and no major differences in principle organization could be found between the two se ... | 1995 | 7666439 |
| concentrations, metabolic clearance rates, production rates and plasma binding of cortisol in antarctic phocid seals. | we have reported previously that plasma of the weddell seal, a member of the phocid family, contains a very high concentration of cortisol. the present study was undertaken to determine whether high cortisol levels were common to seals in the antarctic environment, or to other phocidae, and to determine the mechanism of the hypercortisolaemia. high levels of cortisol (0.82-2.38 mumol/l) were found in 4 phocidae (weddell, crabeater, leopard and southern elephant seals), whereas levels in a member ... | 1993 | 8237255 |
| mercury and major essential elements in seals, penguins, and other representative fauna of the antarctic. | concentrations of total hg and major essential elements, ca, mg, na, and k, were measured in the muscle, liver, and kidney of three species of seals, crabeater seal (lobodon carcinophagus), leopard seal (hydrurga leptonyx), and weddell seal (leptonychotes weddelli) collected in the antarctic. the muscle and liver of three species of penguins, i.e., gentoo penguin (pygoscelis papua), adelie penguin (p. adeliae), chinstrap penguin (p. antarctica), and other representative fauna were also analyzed ... | 1993 | 8239712 |
| the nucleotide sequence of the mitochondrial dna molecule of the grey seal, halichoerus grypus, and a comparison with mitochondrial sequences of other true seals. | the sequence of the mtdna of the grey seal, halichoerus grypus, was determined. the length of the molecule was 16,797 base pairs. the organization of the molecule conformed with that of other eutherian mammals but the control region was unusually long due to the presence of two types of repeated motifs. the grey seal and the previously reported harbor seal, phoca vitulina, belong to different but closely related genera of family phocidae, true (or earless) seals. in order to determine the degree ... | 1993 | 8308902 |
| arterial windkessels in marine mammals. | in marine mammals, the aortic arch is enlarged relative to the descending aorta to varying degrees in different species. the ratio of maximal diameter of the arch to that of the thoracic aorta is about 2.3 in the harbour seal (phoca vitulina), 3.6 in the weddell seal (leptonychotes weddelli) and 3.2 in the fin whale (balaenoptera physalus), compared with only 1.4 in the dog. this anatomical specialisation probably provides increased volume capacitance in the arterial circulation as an adaptation ... | 1995 | 8571227 |
| physiology of diving of birds and mammals. | this review concentrates on the physiological responses, and their control, in freely diving birds and mammals that enable them to remain submerged and sometimes quite active for extended periods of time. recent developments in technology have provided much detailed information on the behavior of these fascinating animals. unfortunately, the advances in technology have been insufficient to enable physiologists to obtain anything like the same level of detail on the metabolic rate and physiologic ... | 1997 | 9234967 |
| immunogenetic evidence for the phylogenetic sister group relationship of dogs and bears (mammalia, carnivora: canidae and crsidae). a comparative determinant analysis of carnivoran albumin, c3 complement and immunoglobulin micro-chain. | thirty-seven antigenic determinants were identified in the albumins, the immunoglobulin micro- and igg(fc) chains, and the c3 proteins of 51 carnivoran (sub)species from 31 genera, and in 12 noncarnivoran mammals. in addition to 19 determinants plesiomorphic for carnivora as an order, 18 synapomorphic epitopes of carnivoran families revealed nine phylogenetic reaction groups: (1) canids, (2) ursids, (3) the racoon, (4) the weddell seal, (5) the lesser panda, (6) the harbour seal, (7) mustelids, ... | 1998 | 9813413 |
| levels and enantiomeric ratios of alpha-hch, oxychlordane, and pcb 149 in blubber of harbour seals (phoca vitulina) and grey seals (halichoerus grypus) from iceland and further species. | the chiral stationary phase beta-tbdm (35% heptakis(6-o-tert.-butyldimethylsilyl-2,3-di-o-methyl)-beta-cyc lod extrin in ov-1701) was applied to study the enantioenrichment of alpha-hch, oxychlordane, and pcb 149 in blubber of two seal species from iceland by gas chromatography with electron capture detection. the examined harbour seals (phoca vitulina) and grey seals (halichoerus grypus) showed alpha-hch enantiomeric ratios (er) > 1. the er of pcb 149 was comparable in the two species from icel ... | 1998 | 9828350 |
| light and scanning electron microscopical study on antarctophthirus ogmorhini lice from the antarctic seal leptonychotes weddellii. | adult lice (antarctophthirus ogmorhini) from the weddell seal leptonychotes weddellii were investigated by means of light and scanning electron microscopy. we established that this species is characterized by several morphological peculiarities which enable it to survive the low temperatures of the antarctic sea and the body depression which occurs during the deep (450 m) and long diving periods of the seals. the main peculiarities are: (1) the cuticle of the ventral and lateral surfaces is much ... | 2002 | 12107458 |
| the cost of foraging by a marine predator, the weddell seal leptonychotes weddellii: pricing by the stroke. | foraging by mammals is a complex suite of behaviors that can entail high energetic costs associated with supporting basal metabolism, locomotion and the digestion of prey. to determine the contribution of these various costs in a free-ranging marine mammal, we measured the post-dive oxygen consumption of adult weddell seals (n=9) performing foraging and non-foraging dives from an isolated ice hole in mcmurdo sound, antarctica. dives were classified according to behavior as monitored by an attach ... | 2004 | 14766956 |
| increasing levels and biomagnification of persistent organic pollutants (pops) in antarctic biota. | representatives of the antarctic food web (krill, cephalopod, fish, penguin, seal) of the area around elephant island and from the weddell sea were analysed for the most recalcitrant organochlorine compounds. due to sorption of the compounds to sinking particles and accumulation in sediments, two benthic fish species (gobionotothen gibberifrons, chaenocephalus aceratus) feeding on benthos invertebrates and fish reflected significantly increasing concentrations within a decade (1987-1996), while ... | 2004 | 14972581 |
| metabolic regulation in diving birds and mammals. | ducks, fur seals, weddell seals and probably most cetaceans seem to be able to dive and remain aerobic for durations that are consistent with their elevated stores of usable oxygen and their metabolic rate while diving being similar to that when they are resting at the surface of the water. ducks, in fact, have a high metabolic rate while diving, mainly because of their large positive buoyancy, but other species have relatively low buoyancy, are better streamlined and use lift-based rather than ... | 2004 | 15288601 |
| occurrence of microbial indicators and clostridium perfringens in wastewater, water column samples, sediments, drinking water, and weddell seal feces collected at mcmurdo station, antarctica. | mcmurdo station, antarctica, has discharged untreated sewage into mcmurdo sound for decades. previous studies delineated the impacted area, which included the drinking water intake, by using total coliform and clostridium perfringens concentrations. the estimation of risk to humans in contact with the impacted and potable waters may be greater than presumed, as these microbial indicators may not be the most appropriate for this environment. to address these concerns, concentrations of these and ... | 2004 | 15574926 |
| isolation and partial characterization of a parapoxvirus isolated from a skin lesion of a weddell seal. | a solitary skin lesion was found on the neck of a weddell seal (leptonychotes weddellii), chemically immobilized in queen maud land (70 degrees 09's, 05 degrees 22'e) antarctica 2001. the lesion was elevated and 3cm in diameter, consisting of partly fresh and partly necrotic tissue, and proliferative papilloma-like structures were seen. electron microscopy on a biopsy from the lesion revealed typical parapoxvirus particles. polymerase chain reaction (pcr; b2l gene) generated amplicons of approxi ... | 2005 | 15681058 |
| blood rheology of weddell seals and bowhead whales. | red blood cell (rbc) aggregation and blood viscosity are important determinants of in vivo blood flow dynamics and, in marine mammals, these parameters may impact diving physiology by altering blood oxygen delivery during the diving response. weddell seals are superb divers and exhibit age-related patterns in blood oxygen chemistry and diving ability. by contrast, bowhead whales are not long duration divers, and little is known of their blood properties relative to diving. the present study was ... | 2006 | 16627927 |
| aerobic dive limit. what is it and is it always used appropriately? | the original definition of aerobic dive limit (adl) was the dive duration after which there is an increase in post-dive concentration of lactate in the blood of weddell seals freely diving in the field. the only other species in which such measurements have been made is the emperor penguin. for all other species, aerobic dive limit has been calculated (cadl) by dividing usable oxygen stores with an estimation of the rate of oxygen consumption during diving. unfortunately, cadl is often referred ... | 2006 | 16846744 |
| control of ventilation in diving birds. | studies on diving ducks indicate that the carotid bodies affect dive duration when the birds are hypoxic before a dive but not when they are hypercapnic. when close to their critical concentrations (beyond which the ducks will not dive), both oxygen and carbon dioxide reduce dive duration but hypercapnia has a much larger influence than hypoxia on surface duration. also, excessive removal of carbon dioxide before a dive may be as important a factor in preparing for that dive as the replacement o ... | 2008 | 18085287 |
| running, swimming and diving modifies neuroprotecting globins in the mammalian brain. | the vulnerability of the human brain to injury following just a few minutes of oxygen deprivation with submergence contrasts markedly with diving mammals, such as weddell seals (leptonychotes weddellii), which can remain underwater for more than 90 min while exhibiting no neurological or behavioural impairment. this response occurs despite exposure to blood oxygen levels concomitant with human unconsciousness. to determine whether such aquatic lifestyles result in unique adaptations for avoiding ... | 2008 | 18089537 |
| trace element analysis in the serum and hair of antarctic leopard seal, hydrurga leptonyx, and weddell seal, leptonychotes weddellii. | leopard seal, hydrurga leptonyx, and weddell seal, leptonychotes weddellii, occupy an upper trophic level within the antarctic ecosystem and are useful indicator species in the southern ocean of trace element concentrations. reference values for the concentration of 19 trace elements were determined in the serum and hair of leopard and weddell seals sampled in eastern antarctica. these reference values can be used as 'baseline' levels for monitoring trace element concentrations in these species. ... | 2008 | 18486190 |
| pleistocene population expansions of antarctic seals. | we sequenced a portion (c. 475 bp) of the mitochondrial control region of three species of antarctic phocid carnivores (weddell seal, leptonychotes weddellii, n = 181; crabeater seal, lobodon carcinophaga, n = 143; and ross seal, ommatophoca rossii, n = 41) that live seasonally or permanently in the fast ice and seasonal pack ice of the western amundsen and ross seas of western antarctica. we resolved 251 haplotypes with a haplotype diversity of 0.98 to 0.99. bayesian estimates of theta from the ... | 2009 | 19344354 |
| morphological features and blood parameters of weddell seal (leptonychotes weddellii) mothers and pups during the breeding season. | we investigated the blood status of 9 weddell seal mothers and 9 pups during the breeding season in a field study conducted from november to december 2004 at a breeding colony in antarctica. the blood glucose and total cholesterol concentrations were higher in the pups than in the mothers. on the other hand, the blood urea nitrogen concentration was lower in the pups than in the mothers. growth-associated depletion of blood triglyceride was observed in the pups and may have been due to the post- ... | 2009 | 19346704 |
| an evaluation of density-dependent and density-independent influences on population growth rates in weddell seals. | much of the existing literature that evaluates the roles of density-dependent and density-independent factors on population dynamics has been called into question in recent years because measurement errors were not properly dealt with in analyses. using state-space models to account for measurement errors, we evaluated a set of competing models for a 22-year time series of mark-resight estimates of abundance for a breeding population of female weddell seals (leptonychotes weddellii) studied in e ... | 2009 | 19449692 |
| isolation and characterization of campylobacter spp. from antarctic fur seals (arctocephalus gazella) at deception island, antarctica. | the presence of campylobacter spp. was investigated in 41 antarctic fur seals (arctocephalus gazella) and 9 weddell seals (leptonychotes weddellii) at deception island, antarctica. infections were encountered in six antarctic fur seals. the isolates, the first reported from marine mammals in the antarctic region, were identified as campylobacter insulaenigrae and campylobacter lari. | 2010 | 20639356 |
| skin microbial flora and effectiveness of aseptic technique for deep muscle biopsies in weddell seals (leptonychotes weddellii ) in mcmurdo sound, antarctica. | deep muscle biopsies were collected from the pectoralis and longissimus dorsi of wild weddell seals (leptonychotes weddellii) in mcmurdo sound, antarctica, during october-december 2007. sterile swabs were collected from the surface of each skin site before biopsy and from the deep-needle path after biopsy. no growth occurred in two of six pectoralis and three of six longissimus skin sites, or in four of 10 pectoralis deep biopsy and eight of 12 longissimus deep-biopsy sites. positive skin cultur ... | 2010 | 20688668 |
| transformation of metabolism with age and lifestyle in antarctic seals: a case study of systems biology approach to cross-species microarray experiment. | the metabolic transformation that changes weddell seal pups born on land into aquatic animals is not only interesting for the study of general biology, but it also provides a model for the acquired and congenital muscle disorders which are associated with oxygen metabolism in skeletal muscle. however, the analysis of gene expression in seals is hampered by the lack of specific microarrays and the very limited annotation of known weddell seal (leptonychotes weddellii) genes. | 2010 | 20920245 |
| purification and inhibition studies with anions and sulfonamides of an a-carbonic anhydrase from the antarctic seal leptonychotes weddellii. | a high activity a-carbonic anhydrase (ca, ec 4.2.1.1) has been purified from various tissues of the antarctic seal leptonychotes weddellii. the new enzyme, denominated lwca, has a catalytic activity for the physiologic co(2) hydration to bicarbonate reaction, similar to that of the high activity human isoform hca ii, with a k(cat) of 1.1×10(6) s(-1), and a k(cat)/k(m) of 1.4×10(8) m(-1) s(-1). the enzyme was highly inhibited by cyanate, thiocyanate, cyanide, bicarbonate, carbonate, as well as su ... | 2011 | 21377369 |
| evaluating the demographic buffering hypothesis with vital rates estimated for weddell seals from 30 years of mark-recapture data. | 1. life-history theory predicts that those vital rates that make larger contributions to population growth rate ought to be more strongly buffered against environmental variability than are those that are less important. despite the importance of the theory for predicting demographic responses to changes in the environment, it is not yet known how pervasive demographic buffering is in animal populations because the validity of most existing studies has been called into question because of method ... | 2012 | 21939440 |
| microcomputer-assisted metabolic studies of voluntary diving of weddell seals. | utilizing a microprocessor-controlled peristaltic withdrawal pump, arterial blood samples were obtained from weddell seals (leptonychotes weddelli) while diving voluntarily under the sea ice at mcmurdo sound, antarctica. plasma concentrations of glucose, lactate, free fatty acids, urea, and amino acids were determined in seals at various times during rest, diving, and recovery. in addition, radiolabeled palmitate, glucose, lactate, p-aminohippurate, inulin, galactose, and cholate were injected i ... | 2012 | 3511736 |
| microcomputer monitor and blood sampler for free-diving weddell seals. | the equipment used for the first sampling of arterial blood at depth on free-diving weddell seals leptonychotes weddelli is described. blood was withdrawn through an aortic catheter by a submersible, peristaltic roller pump and stored in a single- or multiple-sample collection device. the multiple sampler allowed up to eight individual blood samples to be collected during a single dive. the blood pump was controlled by a dedicated microcomputer that allowed initiation of blood sampling at flexib ... | 2013 | 3781968 |
| heart rates in freely diving weddell seals, leptonychotes weddelli. | | 2015 | 4404585 |
| heart rate and body temperature during free diving of weddell seals. | we have developed and successfully used the first microprocessor-controlled monitors for collection of data on depth, heart rate, and body temperature of one fetal and five adult male freely swimming weddell seals. adult seals almost invariably experienced a prompt bradycardia at the start of each dive, and the mean heart rate during diving was significantly lower for dives greater than 20 min (p greater than 0.999). the heart rate was also significantly greater during the ascent portion of dive ... | 2013 | 3618833 |
| escherichia coli out in the cold: dissemination of human-derived bacteria into the antarctic microbiome. | discharge of untreated sewage into antarctic environments presents a risk of introducing non-native microorganisms, but until now, adverse consequences have not been conclusively identified. here we show that sewage disposal introduces human derived escherichia coli carrying mobile genetic elements and virulence traits with the potential to affect the diversity and evolution of native antarctic microbial communities. we compared e. coli recovered from environmental and animal sources in antarcti ... | 2016 | 27179324 |
| serum chemistry and antibodies against pathogens in antarctic fur seals, weddell seals, crabeater seals, and ross seals. | information on health parameters, such as antibody prevalences and serum chemistry that can reveal exposure to pathogens, disease, and abnormal physiologic conditions, is scarce for antarctic seal species. serum samples from antarctic fur seals (arctocephalus gazella, n=88) from bouvetøya (2000-2001 and 2001-2002), and from weddell seals (leptonychotes weddellii, n=20), ross seals (ommatophoca rossii, n=20), and crabeater seals (lobodon carcinophagus, n=9) from the pack-ice off queen maud land, ... | 2012 | 22740529 |
| detection of toxoplasma gondii antibodies in antarctic pinnipeds. | the presence of toxoplasma gondii antibodies was investigated in antarctic marine mammals. two hundred and eleven sera from different species of pinnipeds collected in years 2007, 2010 and 2011 from different locations in the south shetland islands and antarctic peninsula were analysed using a commercially available agglutination test kit. the presence of antibodies (titres ≥ 1:25) against t. gondii was detected in a total of 28 animals (13.3%). amongst animal species, percentages of detection w ... | 2012 | 22726387 |
| contrasting responses to a climate regime change by sympatric, ice-dependent predators. | models that predict changes in the abundance and distribution of fauna under future climate change scenarios often assume that ecological niche and habitat availability are the major determinants of species' responses to climate change. however, individual species may have very different capacities to adapt to environmental change, as determined by intrinsic factors such as their dispersal ability, genetic diversity, generation time and rate of evolution. these intrinsic factors are usually excl ... | 2016 | 26975876 |
| a draft fur seal genome provides insights into factors affecting snp validation and how to mitigate them. | custom genotyping arrays provide a flexible and accurate means of genotyping single nucleotide polymorphisms (snps) in a large number of individuals of essentially any organism. however, validation rates, defined as the proportion of putative snps that are verified to be polymorphic in a population, are often very low. a number of potential causes of assay failure have been identified, but none have been explored systematically. in particular, as snps are often developed from transcriptomes, par ... | 2016 | 26683564 |
| brucella antibody seroprevalence in antarctic seals (arctocephalus gazella, leptonychotes weddellii and mirounga leonina). | brucellosis is a worldwide infectious zoonotic disease caused by gram-negative bacteria of the genus brucella, and brucella infections in marine mammals were first reported in 1994. a serosurvey investigating the presence of anti-brucella antibodies in 3 antarctic pinniped species was undertaken with a protein a/g indirect enzyme-linked immunosorbent assay (ielisa) and the rose bengal test (rbt). serum samples from 33 weddell seals leptonychotes weddelli were analysed, and antibodies were detect ... | 2013 | 23999701 |
| persistent organic pollutants and stable isotopes in pinnipeds from king george island, antarctica. | in the present work, fat, skin, liver and muscle samples from leptonychotes weddellii (weddell seal, n=2 individuals), lobodon carcinophagus (crabeater seal, n=2), arctocephalus gazella (antarctic fur seal, n=3) and mirounga leonina (southern elephant seal, n=1) were collected from king george island, antarctica, and analysed for pops (pcbs, organochlorine pesticides and pbdes) and stable isotopes (δ¹³c and δ¹⁵n in all tissues but fat). pbdes could be found in only one sample (l. weddellii fat). ... | 2012 | 23154138 |
| a colostrum trypsin inhibitor gene expressed in the cape fur seal mammary gland during lactation. | the colostrum trypsin inhibitor (cti) gene and transcript were cloned from the cape fur seal mammary gland and cti identified by in silico analysis of the pacific walrus and polar bear genomes (order carnivora), and in marine and terrestrial mammals of the orders cetartiodactyla (yak, whales, camel) and perissodactyla (white rhinoceros). unexpectedly, weddell seal cti was predicted to be a pseudogene. cape fur seal cti was expressed in the mammary gland of a pregnant multiparous seal, but not in ... | 2016 | 26639991 |
| comparison of analytical and predictive methods for water, protein, fat, sugar, and gross energy in marine mammal milk. | mammalian milks may differ greatly in composition from cow milk, and these differences may affect the performance of analytical methods. high-fat, high-protein milks with a preponderance of oligosaccharides, such as those produced by many marine mammals, present a particular challenge. we compared the performance of several methods against reference procedures using weddell seal (leptonychotes weddellii) milk of highly varied composition (by reference methods: 27-63% water, 24-62% fat, 8-12% cru ... | 2014 | 24931527 |
| to each its own: thermoregulatory strategy varies among neonatal polar phocids. | cold environmental conditions and small body size promote heat loss and may create thermoregulatory challenges for marine mammals born in polar regions. however, among polar-born phocid seal species there are variations in physical attributes and environmental conditions at birth, allowing for an interesting contrast in thermoregulatory strategy. we compared thermoregulatory strategies through morphometrics, sculp attributes (conductivity and resistance), nonshivering thermogenesis (nst via unco ... | 2014 | 25151642 |
| anatomy of the heart of the beluga whale (delphinapterus leucas). | the heart of the beluga whale (delphinapterus leucas) is described from the dissection of seven specimens. as in most whales the heart is characterized by a transverse broadness and a flatness of the ventricles from one surface to the other and by an apex formed by both ventricles. heart size parameters are used for comparison with parameters of other marine and land mammals. the heart width index (heart height/heart circumference) averages 31.3 in comparison to 28.7 for the weddell seal and 39. ... | 1987 | 3820313 |
| plasma angiotensin ii, arginine vasopressin and atrial natriuretic peptide in free ranging and captive seals and sea lions. | we used radioimmunoassay methods to quantify arginine vasopressin (avp), atrial natriuretic peptide (anp), and angiotensin ii (ang ii) in plasma samples from harbor seals (phoca vitulina richardsii), weddell seals (leptonychotes weddellii), northern elephant seals (mirounga angustirostris), ringed seals (phoca hispida), california sea lions (zalophus californianus), and steller sea lions (eumetopias jubatus). plasma concentrations of avp, anp, and ang ii in these pinniped species were within the ... | 1998 | 9568367 |
| polychlorinated naphthalenes in polar environments--a review. | polychlorinated naphthalenes (pcns) consist of naphthalene substituted with 1-8 chlorines, yielding 75 possible congeners. they were formerly used in industry, occur at trace levels in commercial pcb mixtures, and have current sources in combustion processes. pcns are widespread in arctic air with higher levels in the european arctic. concentrations were higher during the cold months in arctic canada and russia, but no seasonality was noted in subarctic canada and greenland. "marker" congeners i ... | 2010 | 19892388 |
| detection of a novel genotype of cryptosporidium in antarctic pinnipeds. | a study was conducted to investigate the presence of cryptosporidium and giardia in antarctic marine mammals. a total of 270 faecal samples from different species of pinnipeds from different locations in the south shetland islands and antarctic peninsula were analysed by immunofluorescence microscopy and pcr. cryptosporidium was detected by pcr in three samples from southern elephant seals (mirounga leonina) and 2 weddell seals (leptonychotes weddellii). however, no oocysts were observed in any ... | 2013 | 23021408 |
| legacy persistent organic pollutants including pbdes in the trophic web of the ross sea (antarctica). | the ecological features of the ross sea trophic web are peculiar and different from other polar food webs, with respect to the use of habitat and species interactions; due to its ecosystem integrity, it is the world's largest marine protected area, established in 2016. polar organisms are reported to bioaccumulate lipophilic contaminant, viz persistent organic pollutants (pops). legacy pops and flame retardants (polybrominated diphenyl ethers, pbdes) were studied in key species of the ross sea ( ... | 2017 | 28732330 |
| marine mammals and emperor penguins: a few applications of the krogh principle. | the diving physiology of aquatic animals at sea began 50 years ago with studies of the weddell seal. even today with the advancements in marine recording and tracking technology, only a few species are suitable for investigation. the first experiments were in mcmurdo sound, antarctica. in this paper are examples of what was learned in antarctica and elsewhere. some methods employed relied on willingness of weddell seals and emperor penguins to dive under sea ice. diving depth and duration were o ... | 2015 | 25411360 |
| environmental extremes versus ecological extremes: impact of a massive iceberg on the population dynamics of a high-level antarctic marine predator. | extreme events have been suggested to play a disproportionate role in shaping ecological processes, but our understanding of the types of environmental conditions that elicit extreme consequences in natural ecosystems is limited. here, we investigated the impact of a massive iceberg on the dynamics of a population of weddell seals. reproductive rates of females were reduced, but survival appeared unaffected. we also found suggestive evidence for a prolonged shift towards higher variability in re ... | 2012 | 23015628 |
| identification of a polyomavirus in weddell seal (leptonychotes weddellii) from the ross sea (antarctica). | viruses are ubiquitous in nature, however, very few have been identified that are associated with antarctic animals. here we report the identification of a polyomavirus in the kidney tissue of a deceased weddell seal from the ross sea, antarctica. the circular genome (5186 nt) has typical features of polyomaviruses with a small and larger t-antigen open reading frames (orfs) and three orfs encoding vp1, vp2 and vp3 capsid proteins. the genome of the weddell seal polyomavirus (wspyv) shares 85.4% ... | 2017 | 28124141 |
| polychloronaphthalenes and other dioxin-like compounds in arctic and antarctic marine food webs. | here we report accumulation patterns of polychlorinated naphthalenes (pcns), polychlorinated dibenzo-p-dioxins (pcdds), polychlorinated dibenzofurans (pcdfs), polychlorinated biphenyls (pcbs), and pesticides (hcb, p,p'dde) in polar organisms (polar bear from alaskan arctic and krill, sharp-spined notothen, crocodile icefish, antarctic silverfish, adélie penguin, south polar skua, and weddell seal from the ross sea, antarctica). pcns, found in most of the samples, ranged from 1.5 pg/g in krill to ... | 2002 | 12214639 |
| polychlorinated dibenzo-p-dioxins, dibenzofurans and polychlorinated biphenyls in polar bear, penguin and south polar skua. | concentrations of 2378-substituted polychlorinated dibenzo-p-dioxins (pcdds), dibenzofurans (dfs) and non- and mono-ortho-substituted polychlorinated biphenyls (dioxin-like pcbs) were measured in livers of polar bears from the alaskan arctic and in eggs of adelie penguin and south polar skua and weddell seal liver, fish and krill from antarctica. this is one of the first reports to document the concentrations of pcdds/dfs in polar bear livers from alaska, and in penguin and skua eggs from antarc ... | 2002 | 12152823 |
| diverse and highly recombinant anelloviruses associated with weddell seals in antarctica. | the viruses circulating among antarctic wildlife remain largely unknown. in an effort to identify viruses associated with weddell seals (leptonychotes weddellii) inhabiting the ross sea, vaginal and nasal swabs, and faecal samples were collected between november 2014 and february 2015. in addition, a weddell seal kidney and south polar skua (stercorarius maccormicki) faeces were opportunistically sampled. using high throughput sequencing, we identified and recovered 152 anellovirus genomes that ... | 2017 | 28744371 |
| physiology of diving in marine mammals. | natural dives are usually short and aerobic, involving swimming effort that is not energetically costly. present evidence indicates few, if any, major biochemical enzyme adaptations that would promote an extended anaerobic capacity in marine mammals. we have discussed the lack of evidence for unusual biochemical adaptations for anaerobiosis and the importance and characteristics of natural aerobic dives. what explanation can we offer for the known capability of some marine mammals, such as wedde ... | 1981 | 7011189 |
| exercise at depth alters bradycardia and incidence of cardiac anomalies in deep-diving marine mammals. | unlike their terrestrial ancestors, marine mammals routinely confront extreme physiological and physical challenges while breath-holding and pursuing prey at depth. to determine how cetaceans and pinnipeds accomplish deep-sea chases, we deployed animal-borne instruments that recorded high-resolution electrocardiograms, behaviour and flipper accelerations of bottlenose dolphins (tursiops truncatus) and weddell seals (leptonychotes weddellii) diving from the surface to >200 m. here we report that ... | 2015 | 25592286 |
| analysis of zp1 gene reveals differences in zona pellucida composition in carnivores. | the zona pellucida (zp) is an extracellular envelope that surrounds mammalian oocytes. this coat participates in the interaction between gametes, induction of the acrosome reaction, block of polyspermy and protection of the oviductal embryo. previous studies suggested that carnivore zp was formed by three glycoproteins (zp2, zp3 and zp4), with zp1 being a pseudogene. however, a recent study in the cat found that all four proteins were expressed. in the present study, in silico and molecular anal ... | 2017 | 28679462 |
| putting the behavior into animal movement modeling: improved activity budgets from use of ancillary tag information. | animal movement research relies on biotelemetry, and telemetry-based locations are increasingly augmented with ancillary information. this presents an underutilized opportunity to enhance movement process models. given tags designed to record specific behaviors, efforts are increasing to update movement models beyond reliance solely upon horizontal movement information to improve inference of space use and activity budgets. we present two state-space models adapted to incorporate ancillary data ... | 2016 | 27878092 |
| growth in pinnipeds. | this review presents summary figures of, and fits growth curves to, data on body lengths (as standard length, sl, whenever possible) of pinnipeds at ages estimated to o.i y. (1) generalized von bertalanffy (vb) growth curves are fitted to most data: lx = l infinity (i - ea(x-x0)b, lx is length at age x, x0 is the origin of the curve (here chosen a priori as time of initiation of embryonic growth), l infinity is asymptotic length, a (which is negative) determines rate of approach to the asymptote ... | 1993 | 8457634 |
| population structure of ice-breeding seals. | the development of population genetic structure in ice-breeding seal species is likely to be shaped by a combination of breeding habitat and life-history characteristics. species that return to breed on predictable fast-ice locations are more likely to exhibit natal fidelity than pack-ice-breeding species, which in turn facilitates the development of genetic differentiation between subpopulations. other aspects of life history such as geographically distinct vocalizations, female gregariousness, ... | 2008 | 18494764 |
| antarctophthirus carlinii (anoplura: echinophthiriidae), a new species from the weddell seal leptonychotes weddelli. | as a part of an ongoing long-term study on the biology of pack-ice seals in antarctica, we had the opportunity to collect lice from weddell seals (leptonychotes weddelli). we did not find the original description of this host-parasite association. antarctophthirus ogmorhini had previously been reported as a parasite for the weddell seal, but the information is, to a certain extent, confusing. during the development of the present study, we had access to literature concerning the presence of a. o ... | 2014 | 25082018 |
| distribution and coassociations of selected metals in seals of the antarctic. | zinc, cu, cd, pb, ag, ni, co, cr, fe and mn concentrations in some tissues of crabeater seal (lobodon carcinophagus), leopard seal (hydrurga leptonyx) and weddell seal (leptonychotes weddelli) from the antarctic were determined. distinct inter-tissue differences in metal concentrations in seals were observed; liver contained maximum levels of zn, cu, ag and mn, whilst kidney showed the highest levels of cd, ni and co. muscle was characterized by low concentrations of all the elements analyzed. t ... | 1994 | 15091740 |
| what difference does a century make? shifts in the ecosystem structure of the ross sea, antarctica, as evidenced from a sentinel species, the weddell seal. | the arrival of humans to antarctica's ross sea (100+ years ago) led to a slow, but sustained increase in human activities in the area. to investigate if human presence has influenced the structure of the ecosystem over the last century, we compared historical (ca 100 years old) and modern samples of a sentinel species, the weddell seal (leptonychotes weddellii), using both bulk tissue and compound-specific stable isotope analysis. the historical isotopic niche of weddell seals was over five time ... | 2017 | 28855359 |
| new data on weddell seal (leptonychotes weddellii) colonies: a genetic analysis of a top predator from the ross sea, antarctica. | in this paper, we studied the genetic variability in weddell seal from colonies in terra nova bay and wood bay, both sites located in the ross sea area, antarctica. two mitochondrial genes and one nuclear gene, with different mutation rates, were sequenced to investigate the haplotype diversity of the colonies and to test for a possible recent expansion. fifteen microsatellites were used to analyze their genetic structure. sequenced genes and microsatellites were also used to estimate the effect ... | 2017 | 28796829 |
| antarctic seals: molecular biomarkers as indicators for pollutant exposure, health effects and diet. | weddell (leptonychotes weddellii), ross (ommatophoca rossii) and crabeater seals (lobodon carcinophaga) are phocid seals with a circumpolar distribution around antarctica. as long-lived and large top predators, they bioaccumulate contaminants and are considered as sentinels of ecosystem health. antarctic seals are increasingly exposed to climate change, pollution, shipping and fisheries. to reveal and understand possible anthropogenic impacts on their immune and health status, this study investi ... | 2017 | 28535598 |
| contrasting behavior between two populations of an ice-obligate predator in east antarctica. | the austral autumn-winter is a critical period for capital breeders such as weddell seals that must optimize resource acquisition and storage to provision breeding in the subsequent spring. however, how weddell seals find food in the winter months remains poorly documented. we equipped adult weddell seals after their annual molt with satellite-relayed data loggers at two sites in east antarctica: dumont d'urville (n = 12, ddu) and davis (n = 20). we used binomial generalized mixed-effect models ... | 2017 | 28116057 |
| coping with the loss of large, energy-dense prey: a potential bottleneck for weddell seals in the ross sea. | extraction of antarctic toothfish (dissostichus mawsoni) in the ross sea began in 1997, following a management plan that targets the largest fish with a goal of reducing the spawning biomass by 50% over 35 yr. we investigate the potential long-term consequences of the reduced availability of this prey for weddell seals (leptonychotes weddellii). energy demands in seals are acute, especially immediately following lactation, when females must recover substantial mass and cope with molting costs. w ... | 2017 | 28052497 |
| patterns of age-related change in reproductive effort differ in the pre-natal and post-natal periods in a long-lived mammal. | age-related changes in maternal reproductive allocation for long-lived species are a key prediction from life-history theory. theoretical and empirical work suggests that allocation may increase with age due to constraint (increases with experience) or restraint (increases with age in the face of declining residual reproductive value), and may decrease among the oldest aged animals due to senescence in reproductive function. here, we use a hierarchical modelling approach to investigate the age-r ... | 2016 | 27448960 |
| bimodal winter haul-out patterns of adult weddell seals (leptonychotes weddellii) in the southern weddell sea. | hauling out is an essential component of pinniped life-history. haul-out behaviour may be affected by biological (e.g. sex, age and condition) and physical factors (e.g. food availability and environmental conditions), and identifying these factors may help explain the spatio-temporal distribution and habitat use of pinnipeds. the aim of this study is to describe observed winter haul-out patterns of adult weddell seals in the weddell sea and investigate the role of potential predictors to gain i ... | 2016 | 27196097 |
| birth dates vary with fixed and dynamic maternal features, offspring sex, and extreme climatic events in a high-latitude marine mammal. | reproductive synchrony tends to be widespread in diverse species of plants and animals, especially at higher latitudes. however, for long-lived mammals, birth dates for different individuals can vary by weeks within a population. a mother's birth timing can reveal useful information about her reproductive abilities and have important implications for the characteristics and survival of her offspring. despite this, our current knowledge of factors associated with variation in birth dates is modes ... | 2016 | 27099704 |
| joint estimation over multiple individuals improves behavioural state inference from animal movement data. | state-space models provide a powerful way to scale up inference of movement behaviours from individuals to populations when the inference is made across multiple individuals. here, i show how a joint estimation approach that assumes individuals share identical movement parameters can lead to improved inference of behavioural states associated with different movement processes. i use simulated movement paths with known behavioural states to compare estimation error between nonhierarchical and joi ... | 2016 | 26853261 |
| field use of ultrasonography to characterize the reproductive tract and early pregnancy in a phocid, the weddell seal (leptonychotes weddellii). | the utility of transrectal ultrasonography was tested in a field setting to characterize the reproductive tract and detect early pregnancy (embryonic vesicles < 3 mm in diameter) in 17 multiparous female weddell seals (leptonychotes weddellii). female weddell seals give birth in october/november each year, followed by the breeding season (december) and embryonic diapause. transrectal ultrasonography was attempted in january/february 2014 to examine the entire reproductive tract (uterine horns an ... | 2015 | 26340607 |
| female weddell seals show flexible strategies of colony attendance related to varying environmental conditions. | many animal life cycles involve movements among different habitats to fulfill varying resource demands. there are inherent costs associated with such movements, and the decision to leave or stay at a given location ought to be motivated by the benefits associated with potential target habitats. because movement patterns, especially those associated with reproduction, can have important implications for the success (survival, reproduction) of individual animals, and therefore a population's dynam ... | 2015 | 26240869 |
| scaling matters: incorporating body composition into weddell seal seasonal oxygen store comparisons reveals maintenance of aerobic capacities. | adult weddell seals (leptonychotes weddellii) haul-out on the ice in october/november (austral spring) for the breeding season and reduce foraging activities for ~4 months until their molt in the austral fall (january/february). after these periods, animals are at their leanest and resume actively foraging for the austral winter. in mammals, decreased exercise and hypoxia exposure typically lead to decreased production of o2-carrying proteins and muscle wasting, while endurance training increase ... | 2015 | 26164426 |
| the evolutionary significance of latent reproductive rate in a long-lived vertebrate. | chambert, rotella & garrott () used long-term data to assess the evolutionary significance of individual latent reproductive rate in female weddell seals. latent reproductive rates capture the differences among individuals in terms of their propensity to breed; they are conceptual and mathematical constructs. neither recruitment probability nor age of first breeding of daughters was related to the mother's latent reproductive rate, but there was evidence of a weak positive relationship between t ... | 2014 | 26050743 |
| locomotion and the cost of hunting in large, stealthy marine carnivores. | foraging by large (>25 kg), mammalian carnivores often entails cryptic tactics to surreptitiously locate and overcome highly mobile prey. many forms of intermittent locomotion from stroke-and-glide maneuvers by marine mammals to sneak-and-pounce behaviors by terrestrial canids, ursids, and felids are involved. while affording proximity to vigilant prey, these tactics are also associated with unique energetic costs and benefits to the predator. we examined the energetic consequences of intermitte ... | 2015 | 25936358 |
| tight coupling of primary production and marine mammal reproduction in the southern ocean. | polynyas are areas of open water surrounded by sea ice and are important sources of primary production in high-latitude marine ecosystems. the magnitude of annual primary production in polynyas is controlled by the amount of exposure to solar radiation and sensitivity to changes in sea-ice extent. the degree of coupling between primary production and production by upper trophic-level consumers in these environments is not well understood, which prevents reliable predictions about population traj ... | 2015 | 25854885 |
| perfluoroalkyl substances detected in the world's southernmost marine mammal, the weddell seal (leptonychotes weddellii). | this study investigates concentrations of 18 perfluoroalkyl substances (pfas) in blood plasma of adult lactating weddell seals (leptonychotes weddellii) (n = 10) from mcmurdo sound, antarctica. perfluoroundecanoic acid (pfunda) was detected in all samples at concentrations ranging from 0.08 to 0.23 ng/ml. perfluorooctane sulfonate (pfos), perfluorohexanoate (pfhxa) and perfluorotridecanoate (pftrida) were sporadically detected, while the remaining compounds were below the limit of detection. thi ... | 2015 | 25497307 |
| heat loss in air of an antarctic marine mammal, the weddell seal. | the conflicting needs of homeostasis in air versus water complicate our understanding of thermoregulation in marine mammals. large-scale modeling efforts directed at predicting the energetic impact of changing sea ice conditions on polar ecosystems require a better understanding of thermoregulation in air of free-ranging animals. we utilized infrared imaging as an indirect approach to determine surface temperatures of dry, hauled-out weddell seals (leptonychotes weddellii, n = 35) of varying age ... | 2015 | 25378218 |
| a new method to quantify within dive foraging behaviour in marine predators. | studies on diving behaviour classically divide a dive into three phases: the descent, bottom and ascent phases, with foraging assumed to occur during the bottom phase. the greater complexity of dive revealed through modern, high resolution data highlights the need to re-assess this approach and to consider a larger number of phases within individual dives. two southern elephant seals (ses) were fitted with a head mounted time depth recorder (tdr) and an accelerometer from which prey capture atte ... | 2014 | 24922323 |
| use of posterior predictive checks as an inferential tool for investigating individual heterogeneity in animal population vital rates. | the investigation of individual heterogeneity in vital rates has recently received growing attention among population ecologists. individual heterogeneity in wild animal populations has been accounted for and quantified by including individually varying effects in models for mark-recapture data, but the real need for underlying individual effects to account for observed levels of individual variation has recently been questioned by the work of tuljapurkar et al. (ecology letters, 12, 93, 2009) o ... | 2014 | 24834335 |
| an evolutionary perspective on reproductive individual heterogeneity in a marine vertebrate. | although the quantification of individual heterogeneity in wild populations' vital rates has recently attracted growing interest among ecologists, the investigation of its evolutionary consequences remains limited, mainly because of the difficulties in assessing fitness and heritability from field studies on free-ranging animals. in the presence of individual variability, evaluation of fitness consequences can notably be complicated by the existence of trade-offs among different vital rates. in ... | 2014 | 24673453 |
| improving the precision of our ecosystem calipers: a modified morphometric technique for estimating marine mammal mass and body composition. | mass and body composition are indices of overall animal health and energetic balance and are often used as indicators of resource availability in the environment. this study used morphometric models and isotopic dilution techniques, two commonly used methods in the marine mammal field, to assess body composition of weddell seals (leptonychotes weddellii, n = 111). findings indicated that traditional morphometric models that use a series of circular, truncated cones to calculate marine mammal blu ... | 2014 | 24614685 |
| individual heterogeneity in reproductive rates and cost of reproduction in a long-lived vertebrate. | individual variation in reproductive success is a key feature of evolution, but also has important implications for predicting population responses to variable environments. although such individual variation in reproductive outcomes has been reported in numerous studies, most analyses to date have not considered whether these realized differences were due to latent individual heterogeneity in reproduction or merely random chance causing different outcomes among like individuals. furthermore, la ... | 2013 | 23919151 |
| milk composition in the weddell seal leptonychotes weddellii: evidence for a functional role of milk carbohydrates in pinnipeds. | we propose that secretion of milk sugar has important consequences for the metabolic economies of lactating phocid seals and their pups. milk was collected from 21 weddell seals leptonychotes weddellii in mcmurdo sound, antarctica, and assayed by standard methods. milk composition changed over the course of lactation, but at mid- to late lactation (16-40 d postpartum), weddell seal milk composition was relatively constant at 33.8% +/- 0.82% water, 54.0% +/- 0.80% fat, 10.1% +/- 0.16% crude prote ... | 2013 | 23434776 |
| assessment of legacy and emerging persistent organic pollutants in weddell seal tissue (leptonychotes weddellii) near mcmurdo sound, antarctica. | muscle samples were collected from pup, juvenile and adult weddell seals (leptonychotes weddellii) near mcmurdo sound, antarctica during the austral summer of 2006. blubber samples were collected from juvenile and adult seals. samples were analyzed for emerging and legacy persistent organic pollutants (pops) including current and historic-use organochlorine pesticides, polychlorinated biphenyls (pcbs), and polybrominated diphenyl ethers (pbdes). of the 41 target analytes, 28 contaminants were re ... | 2012 | 23085468 |
| aerobic dive limits of seals with mutant myoglobin using combined thermochemical and physiological data. | this paper presents an integrated model of convective o(2)-transport, aerobic dive limits (adl), and thermochemical data for oxygen binding to mutant myoglobin (mb), used to quantify the impact of mutations in mb on the dive limits of weddell seals (leptonychotes weddellii). we find that wild-type mb traits are only superior under specific behavioral and physiological conditions that critically prolong the adl, action radius, and fitness of the seals. as an extreme example, the mutations in the ... | 2013 | 23085290 |