| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| long-range underwater vocalizations of the crabeater seal (lobodon carcinophaga). | this study provides a comprehensive description of the acoustic characteristics of the predominant long-range underwater vocalizations of the crabeater seal, lobodon carcinophaga, derived from stationary and continuous long-term recordings obtained in the southern ocean in 2007. visual screening of data recorded between 1 october and 15 december 2007 indicates that the principal period of vocal activity of the crabeater seal is the latter part of october and all of november, coinciding with the ... | 2010 | 20649241 |
| 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 |
| 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 |
| digestibility of krill (euphausia superba and thysanoessa sp.) in minke whales (balaenoptera acutorostrata) and crabeater seals (lobodon carcinophagus). | apparent digestible efficiency (% de) was studied by use of dietary mn as an inert marker, in minke whales (balaenoptera acutorostrata) and crabeater seals (lobodon carcinophagus) which had been eating krill. median % de in minke whales (n5) eating krill of the genus thysanoessa sp. (energy density (ed) 23.8 kj/g) was 93 (range 87-93). median % de in crabeater seals (n6) eating krill of the species euphausia superba (ed 20.8 kj/g) was 84 (range 79-85), which is significantly lower than the % de ... | 1994 | 7826994 |
| the better to eat you with: the comparative feeding morphology of phocid seals (pinnipedia, phocidae). | one adaptation crucial to the survival of mammalian lineages that secondarily transitioned from land to water environments was the ability to capture and consume prey underwater. phocid seals have evolved diverse feeding strategies to feed in the marine environment, and the objectives of this study were to document the specialized feeding morphologies and identify feeding strategies used by extant phocids. this study used principal component analysis (pca) to determine the major axes of diversif ... | 2016 | 26646351 |
| [diphyllobothrium lobodoni sp. n. (cestoda: diphyllobothriidae)--a parasite of the crabeater seal]. | the new cestode species is described from the intestine of the crab eater seal lobodon carcinophagus living in pacific region of antarctic. it differs from other diphyllobothriids by clear wavy lateral margins of the body. it is close to d. scoticum by the presence of uterine sack, but it has larger size of the body, lesser craspedotity of segments, lesser size of scolex, longer neck, thinner tegument, 3 times thicker layers of longitudinal and transversal muscles, 2 times greater number of test ... | 2007 | 7816509 |
| ddt residues in adelie penguins and a crabeater seal from antarctica. | | 1966 | 5961190 |
| ancient whales did not filter feed with their teeth. | the origin of baleen whales (mysticeti), the largest animals on earth, is closely tied to their signature filter-feeding strategy. unlike their modern relatives, archaic whales possessed a well-developed, heterodont adult dentition. how these teeth were used, and what role their function and subsequent loss played in the emergence of filter feeding, is an enduring mystery. in particular, it has been suggested that elaborate tooth crowns may have enabled stem mysticetes to filter with their postc ... | 2017 | 28855416 |
| 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 |
| 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 |
| sexing pinnipeds with zfx and zfy loci. | we developed and tested a protocol for determining the sex of individual pinnipeds using the sex-chromosome-specific genes zfx and zfy. we screened a total of 368 seals (168 crabeater, lobodon carcinophaga; 159 weddell, leptonychotes weddellii; and 41 ross, ommatophoca rossii) of known or unknown sex and compared the molecular sex to the sex assigned at the time of biopsy sample collection in the ross and amundsen seas, antarctica. we also screened 6 captive northern elephant seals (mirounga ang ... | 2007 | 17548861 |
| lectinhistochemical observations on the bronchial glands and the goblet cells of the airway epithelium of marine diving mammals. | carbohydrate components were investigated in the bronchial glands and goblet cells of two species of seals with different diving habits (weddell seal, crabeater seal). bouin-fixed tissue was incubated with various fluorescein-iso-thiocyanate-conjugated lectins (wga, rca i, pna, pha i, hpa, gsa i, dba, con a, lfa, sba, uea i), additionally pas- and hid-reactions as well as alcian blue stains were applied. the two species differ in respect of their carbohydrate histochemistry, e.g., the pas reacti ... | 1988 | 3150558 |
| accommodating unmodeled heterogeneity in double-observer distance sampling surveys. | mark-recapture models applied to double-observer distance sampling data neglect the information on relative detectability of objects contained in the distribution of observed distances. a difference between the observed distribution and that predicted by the mark-recapture model is symptomatic of a failure of the assumption of zero correlation between detection probabilities implicit in the mark-recapture model. we develop a mark-recapture-based model that uses the observed distribution to relax ... | 2006 | 16918901 |
| breeding season and embryonic diapause in crabeater seals (lobodon carcinophagus). | direct observation of 387 embryos in the early stages of development was combined with observations on breeding behaviour and reproductive biology obtained from the published literature, to estimate the timing of births, oestrus, ovulation and implantation, and to derive estimates of the duration of pregnancy, embryonic diapause and active gestation for crabeater seals (lobodon carcinophagus). the total duration of pregnancy (conception to birth) is estimated to be 11.3 months (344 days). it is ... | 2003 | 12968944 |
| identification of 2'-fucosyllactose in milk of the crabeater seal (lobodon carcinophagus). | 1. an oligosaccharide was isolated from extracts of crabeater seal milk by preparative paper chromatography. 2. the saccharide was identified as fuc alpha 1-2ga1 beta 1-4g1c by 1h-nmr spectroscopy. 3. this work represents the first identification of an oligosaccharide, other than lactose, in the milk of a pinniped. | 1997 | 9114490 |
| studies on the carbohydrate content of milk of the crabeater seal (lobodon carcinophagus). | 1. the mean carbohydrate content of six samples of milk of the crabeater seal (a phocid), measured as total hexose, was 1.5 +/- 0.3% (w/v). ultrafiltrates of the skim milk of these samples had a mean carbohydrate content of 1.9 +/- 0.2%. 2. thin-layer chromatography of the ultrafiltrates showed that this carbohydrate consists mainly of various oligosaccharides of low chromatographic mobility; lactose and traces of free glucose and galactose were also detected. 3. these oligosaccharides consisted ... | 1988 | 3409663 |
| intestinal lactase and other disaccharidase activities of a suckling crabeater seal (lobodon carcinophagus). | 1. the intestinal disaccharidase activities of a suckling crabeater seal were investigated. 2. lactase, maltase, isomaltase and cellobiase activities were readily detected but trehalase and sucrase activities were absent. 3. the intestinal homogenates were separated into a soluble (s2) fraction and a particulate brush border (p2) fraction. the lactase activities of the two fractions had different properties corresponding to those of an acid and a neutral beta-galactosidase respectively. approxim ... | 1988 | 3136970 |
| fine structure of seminiferous tubules in antarctic seals. | the fine structure of seminiferous tubules from 5 crabeater, 2 leopard and 2 ross seals showed that during the nonbreeding season the tubules were essentially similar in possessing spermatogenic and sertoli cells. however, the tubules of leopard and ross seals had more primary and secondary spermatocytes and spermatids than the crabeater seals. in general, the tubules were devoid of spermatozoa. the spermatids showed stages of maturation such as golgi phase of acrosome formation, acrosomal cap f ... | 1977 | 844074 |
| mummified seal carcasses in the mcmurdo sound region, antarctica. | information was collected on 90 mummified carcasses of the "crabeater" seal in the ice-free areas of the mcmurdo sound region, antarctica. the carcasses range from relatively well-preserved bodies to merely old, twisted, winddissected fragments of tissue. they are hard and dry and lie on the surface of the ground, mostly in valley bottoms. the arid, cold climate is ideal for retarding organic decay. one carcass was dated by radiocarbon analysis and found to be between 1600 and 2600 years old. | 1959 | 14432467 |
| so happy together: juvenile crabeater seal behavior improves lice transmission. | lice from family echinophthiriidae are of the few insects that have successfully colonized marine environment living as ectoparasites of pinnipeds, i.e., sea lions, seals, and the walrus. they have developed unique adaptations to cope with the amphibious lifestyle of their hosts. because eggs do not survive underwater, lice could only reproduce when their host remains on pack ice enough time. consequently, lice generations per year are limited by host haul-out behavior. the objective of this wor ... | 2020 | 32447516 |
| the kidney of leptonychotes weddelli (pinnipedia: phocidae) with some observations on the kidneys of two other southern phocid seals. | the structure of the kidney of leptonychotes weddelli was examined using corrosion casts, india ink injection, and histological methods. some observations were made on the kidney of the crabeater seal (lobodon carcinophagus) and the elephant seal (mirounga leonina). the kidneys in all three species are reniculate, as in many other marine mammalian species. features that have not been described previously in a phocid seal are a peripyramidal muscle, and venous drainage characterized by a large ex ... | 1981 | 30139187 |