walruses

Summary

Summary: The family Odobenidae, suborder PINNIPEDIA, order CARNIVORA. It is represented by a single species of large, nearly hairless mammal found on Arctic shorelines, whose upper canines are modified into tusks.

Top Publications

  1. Leclair D, Forbes L, Suppa S, Proulx J, Gajadhar A. A preliminary investigation on the infectivity of Trichinella larvae in traditional preparations of walrus meat. Parasitol Res. 2004;93:507-9 pubmed
    ..Further research is needed to evaluate the food safety risk of traditional walrus igunaq aged under different field conditions and storage times...
  2. Levermann N, Galatius A, Ehlme G, Rysgaard S, Born E. Feeding behaviour of free-ranging walruses with notes on apparent dextrality of flipper use. BMC Ecol. 2003;3:9 pubmed
    ..This is particularly true for large and potentially dangerous species such as the walrus (Odobenus rosmarus). Walruses are highly specialised predators on benthic invertebrates - especially bivalves...
  3. Leclair D, Forbes L, Suppa S, Gajadhar A. Evaluation of a digestion assay and determination of sample size and tissue for the reliable detection of Trichinella larvae in walrus meat. J Vet Diagn Invest. 2003;15:188-91 pubmed
    ..walrus (Odobenus rosmarus) meat, and appropriate samples for testing were determined using tissues from infected walruses harvested for food...
  4. Proulx J, MacLean J, Gyorkos T, Leclair D, Richter A, Serhir B, et al. Novel prevention program for trichinellosis in inuit communities. Clin Infect Dis. 2002;34:1508-14 pubmed
    ..This report describes the events that occurred before, during, and after the trichinellosis outbreak and also documents how the prevention program contributed to successful resolution of the outbreak...
  5. Duignan P, Saliki J, St Aubin D, House J, Geraci J. Neutralizing antibodies to phocine distemper virus in Atlantic walruses (Odobenus rosmarus rosmarus) from Arctic Canada. J Wildl Dis. 1994;30:90-4 pubmed
    The first evidence of phocine distemper virus (PDV) infection in Atlantic walruses (Odobenus rosmarus rosmarus) from Nottingham Island, Northwest Territories, Canada, is reported...
  6. MacLean J, Poirier L, Gyorkos T, Proulx J, Bourgeault J, Corriveau A, et al. Epidemiologic and serologic definition of primary and secondary trichinosis in the Arctic. J Infect Dis. 1992;165:908-12 pubmed
  7. Møller L, Petersen E, Kapel C, Melbye M, Koch A. Outbreak of trichinellosis associated with consumption of game meat in West Greenland. Vet Parasitol. 2005;132:131-6 pubmed
    ..Trichinellosis in Greenland can be prevented by the implementation of public health measures...
  8. Seibel H, Stimmer L, Siebert U, Beineke A. Immunohistochemical characterization of selected cell markers for the detection of hematopoietic cells in formalin-fixed, paraffin wax-embedded lymphoid tissues of harbor seals (Phoca vitulina) and walruses (Odobenus rosmarus rosmarus). Vet Immunol Immunopathol. 2010;137:305-9 pubmed publisher
  9. Metcalf V, Robards M. Sustaining a healthy human-walrus relationship in a dynamic environment: challenges for comanagement. Ecol Appl. 2008;18:S148-56 pubmed
    ..Here we present an overview of the challenges, needs, and research relating to climate change that are of interest to the EWC and in particular, the sustained health of the human-walrus relationship...

More Information

Publications83

  1. Pharo E, Cane K, McCoey J, Buckle A, Oosthuizen W, Guinet C, et al. A colostrum trypsin inhibitor gene expressed in the Cape fur seal mammary gland during lactation. Gene. 2016;578:7-16 pubmed publisher
    ..Therefore, pinniped CTI may be critical for preventing the proteolytic degradation of immunoglobulins that are passively transferred from mother to young via colostrum and milk. ..
  2. Loch C, Boessenecker R, Churchill M, Kieser J. Enamel ultrastructure of fossil and modern pinnipeds: evaluating hypotheses of feeding adaptations in the extinct walrus Pelagiarctos. Naturwissenschaften. 2016;103:44 pubmed publisher
  3. Tsygankov V, Boyarova M, Lukyanova O. Bioaccumulation of persistent organochlorine pesticides (OCPs) by gray whale and Pacific walrus from the western part of the Bering Sea. Mar Pollut Bull. 2015;99:235-9 pubmed publisher
    ..The total OCP concentration (∑HCH+∑DDT) in muscles and liver of the Pacific walruses varies from 197 to 5659 and from 4856 to 90,263 ng/g lipids, respectively...
  4. Nakagun S, Watanabe H, Ochiai K, Kohyama K, Goshima W, Goto Y, et al. Extralobar pulmonary sequestration in two pinniped species. J Vet Med Sci. 2017;79:1791-1794 pubmed publisher
    ..The pinniped cases presented are exceptionally rare and to the best of the authors' knowledge, marks the first descriptions of this congenital anomaly in wildlife...
  5. Neigel A, Claypoole V, Hancock G, Fraulini N, Szalma J. Ceci n'est pas un walrus: lexical processing in vigilance performance. Exp Brain Res. 2018;236:867-879 pubmed publisher
    ..We also discuss the effect of lure stimuli on measures related to signal detection theory (e.g., sensitivity and response bias). ..
  6. Sandanger T, Brustad M, Odland J, Doudarev A, Miretsky G, Chaschin V, et al. Human plasma levels of POPs, and diet among native people from Uelen, Chukotka. J Environ Monit. 2003;5:689-96 pubmed
    ..Transportation of beta-HCH by ocean currents through the Bering Strait into the Arctic Ocean or regional point sources might explain these elevated levels...
  7. Tsygankov V, Lukyanova O, Boyarova M. Organochlorine pesticide accumulation in seabirds and marine mammals from the Northwest Pacific. Mar Pollut Bull. 2018;128:208-213 pubmed publisher
    ..The environmental assessment of the Northwest Pacific marine ecosystems revealed that the levels of OCP contamination in this area are similar to the other subarctic regions of the World Ocean. ..
  8. Ahonen H, Harcourt R, Stow A, Charrier I. Geographic vocal variation and perceptual discrimination abilities in male Australian sea lions. Anim Cogn. 2018;21:235-243 pubmed publisher
    ..Pinnipeds (seals, fur seals, sea lions and walruses) are highly vocal yet the Australian sea lion (Neophoca cinerea) is the only eared seal known to show geographic ..
  9. Beklemisheva V, Perelman P, Lemskaya N, Kulemzina A, Proskuryakova A, Burkanov V, et al. The Ancestral Carnivore Karyotype As Substantiated by Comparative Chromosome Painting of Three Pinnipeds, the Walrus, the Steller Sea Lion and the Baikal Seal (Pinnipedia, Carnivora). PLoS ONE. 2016;11:e0147647 pubmed publisher
    ..The study underlined the strikingly slow karyotype evolution of the Pinnipedia in general and the Otariidae in particular. ..
  10. Kakehi M, Ikenaka Y, Nakayama S, Kawai Y, Watanabe K, Mizukawa H, et al. Uridine Diphosphate-Glucuronosyltransferase (UGT) Xenobiotic Metabolizing Activity and Genetic Evolution in Pinniped Species. Toxicol Sci. 2015;147:360-9 pubmed publisher
  11. Hamilton T, Seagars D, Jokela T, Layton D. 137Cs and 210Po in Pacific walrus and bearded seal from St. Lawrence Island, Alaska. Mar Pollut Bull. 2008;56:1158-67 pubmed publisher
    ..This work has important implications for assessment of risks of Alaskan coastal communities concerned about the dumping of nuclear waste in the Russia Arctic. ..
  12. Nielsen O, Clavijo A, Boughen J. Serologic evidence of influenza A infection in marine mammals of arctic Canada. J Wildl Dis. 2001;37:820-5 pubmed
    ..5%) ringed seals (Phoca hispida) were serologically positive. None of the 210 walruses (Odobenus rosmarus rosmarus), 76 narwhals (Monodon monoceros) and four bowhead whales (Balaena mysticetus) had ..
  13. Yan R, Huang J, Li L, Gao J. Hydrology and phosphorus transport simulation in a lowland polder by a coupled modeling system. Environ Pollut. 2017;227:613-625 pubmed publisher
  14. Winer J, Arzi B, Leale D, Kass P, Verstraete F. Dental and Temporomandibular Joint Pathology of the Walrus (Odobenus rosmarus). J Comp Pathol. 2016;155:242-253 pubmed publisher
    Maxillae and/or mandibles from 76 walruses (Odobenus rosmarus) were examined macroscopically according to predefined criteria. The museum specimens were acquired between 1932 and 2014. Forty-five specimens (59...
  15. Tsygankov V, Boyarova M, Lukyanova O, Khristoforova N. Bioindicators of Organochlorine Pesticides in the Sea of Okhotsk and the Western Bering Sea. Arch Environ Contam Toxicol. 2017;73:176-184 pubmed publisher
    ..The concentrations and possible sources of OCPs in marine organisms as biological indicators are discussed. ..
  16. Pinzari F, Tate J, Bicchieri M, Rhee Y, Gadd G. Biodegradation of ivory (natural apatite): possible involvement of fungal activity in biodeterioration of the Lewis Chessmen. Environ Microbiol. 2013;15:1050-62 pubmed publisher
    ..Colonization of ivory and/or exposure to fungal activity lead to extensive secondary biomineral formation, and this was identified as calcium oxalate, mainly as the monohydrate, whewellite. ..
  17. Trukhin A, Simokon M. Mercury in organs of Pacific walruses (Odobenus rosmarus divergens) from the Bering Sea. Environ Sci Pollut Res Int. 2018;25:3360-3367 pubmed publisher
    ..Total mercury (THg) concentration was measured in eight internal organs of walruses. Samples were taken from 22 individuals (11 males and 11 females). Age of the animals ranged from 1 to 30 years...
  18. Skeríková A, Brabec J, Kuchta R, Jimenez J, Garcia H, Scholz T. Is the human-infecting Diphyllobothrium pacificum a valid species or just a South American population of the holarctic fish broad tapeworm, D. latum?. Am J Trop Med Hyg. 2006;75:307-10 pubmed
    ..0-98.0% and 98.2-99.9%, respectively. Phylogenetic trees constructed from ITS2 sequences show a markedly distant position of D. pacificum from other species analyzed and also indicate the possible paraphyly of Spirometra...
  19. Prestrud K, Asbakk K, Fuglei E, Mørk T, Stien A, Ropstad E, et al. Serosurvey for Toxoplasma gondii in arctic foxes and possible sources of infection in the high Arctic of Svalbard. Vet Parasitol. 2007;150:6-12 pubmed
    ..390 Svalbard reindeer (Rangifer tarandus platyrhynchus), 361 sibling voles (Microtus rossiaemeridionalis), 17 walruses (Odobenus rosmarus), 149 barnacle geese (Branta leucopsis), 58 kittiwakes (Rissa tridactyla), and 27 glaucous ..
  20. Fago A, Parraga D, Petersen E, Kristensen N, Giouri L, Jensen F. A comparison of blood nitric oxide metabolites and hemoglobin functional properties among diving mammals. Comp Biochem Physiol A Mol Integr Physiol. 2017;205:35-40 pubmed publisher
    ..Taken together, these results underscore adaptive variations in circulatory NO metabolism in diving mammals but not in the oxygenation properties of the Hb. ..
  21. Lefebvre K, Quakenbush L, Frame E, Huntington K, Sheffield G, Stimmelmayr R, et al. Prevalence of algal toxins in Alaskan marine mammals foraging in a changing arctic and subarctic environment. Harmful Algae. 2016;55:13-24 pubmed publisher
    ..fur seals, Steller sea lions, harbor seals, ringed seals, bearded seals, spotted seals, ribbon seals, Pacific walruses, and northern sea otters...
  22. Charrier I, Aubin T, Mathevon N. Mother-calf vocal communication in Atlantic walrus: a first field experimental study. Anim Cogn. 2010;13:471-82 pubmed publisher
    ..This experimental study clearly demonstrates that Atlantic walrus has developed a highly reliable mother-calf vocal communication allowing such strong social bond...
  23. Dehn L, Follmann E, Thomas D, Sheffield G, Rosa C, Duffy L, et al. Trophic relationships in an Arctic food web and implications for trace metal transfer. Sci Total Environ. 2006;362:103-23 pubmed
    ..Metal deposition in animal tissues is strongly dependent on biological factors such as diet, age, sex, body condition and health, and caution should be taken when interpreting magnification of dynamic and actively regulated trace metals...
  24. Heide Jørgensen M, Burt L, Hansen R, Nielsen N, Rasmussen M, Fossette S, et al. The significance of the north water polynya to arctic top predators. Ambio. 2013;42:596-610 pubmed publisher
    ..b>Walruses (Odobenus rosmarus) were found across the North Water over both shallow and deep (>500 m) water with an ..
  25. Ganova Raeva L, Smith A, Fields H, Khudyakov Y. New Calicivirus isolated from walrus. Virus Res. 2004;102:207-13 pubmed publisher
    ..ORF3 overlapped ORF2 and encoded a small basic protein. Comparative analysis of multiple caliciviral capsid proteins was performed to propose a uniform capsid structural organization for this viral family...
  26. Kastelein R, Mosterd P, van Santen B, Hagedoorn M, de Haan D. Underwater audiogram of a Pacific walrus (Odobenus rosmarus divergens) measured with narrow-band frequency-modulated signals. J Acoust Soc Am. 2002;112:2173-82 pubmed
    ..The thresholds found during a small test with four frequencies with signal durations of 300 ms did not differ significantly from those obtained with signal durations of 1500 ms...
  27. Foster G, Macmillan A, Godfroid J, Howie F, Ross H, Cloeckaert A, et al. A review of Brucella sp. infection of sea mammals with particular emphasis on isolates from Scotland. Vet Microbiol. 2002;90:563-80 pubmed
    ..Two new species B. cetaceae and B. pinnipediae have been proposed as a result. This paper provides a review of Brucella in sea mammals and updates findings from the study of sea mammals from around the coast of Scotland...
  28. Orr M, Hittel K, Lukowiak K. Predator detection enables juvenile Lymnaea to form long-term memory. J Exp Biol. 2010;213:301-7 pubmed publisher
    ..e. enhanced LTM formation) in juveniles, which may increase their fitness. These data also support the notion that learning and memory formation in conjunction with predator detection is a form of inducible defense...
  29. Seagars D, Garlich Miller J. Organochlorine compounds and aliphatic hydrocarbons in Pacific walrus blubber. Mar Pollut Bull. 2001;43:122-31 pubmed
    ..Small sample sizes, a lack of samples from immature animals, and uniformly low concentrations of contaminants precluded meaningful analysis of age-related effects and regional differences...
  30. McLaren I. Growth in pinnipeds. Biol Rev Camb Philos Soc. 1993;68:1-79 pubmed
    ..The Baikal seal is confirmed as the smallest species of pinniped.(ABSTRACT TRUNCATED AT 400 WORDS)..
  31. Monson D, Udevitz M, Jay C. Estimating age ratios and size of pacific walrus herds on coastal haulouts using video imaging. PLoS ONE. 2013;8:e69806 pubmed publisher
    During Arctic summers, sea ice provides resting habitat for Pacific walruses as it drifts over foraging areas in the eastern Chukchi Sea...
  32. Lyamin O, Kosenko P, Vyssotski A, Lapierre J, Siegel J, Mukhametov L. Study of sleep in a walrus. Dokl Biol Sci. 2012;444:188-91 pubmed publisher
  33. Kinoshita K, Kiwata M, Kuwano R, Sato N, Tanaka T, Nagata M, et al. Temporal association of serum progesterone concentrations and vaginal cytology in walruses (Odobenus rosmarus). Theriogenology. 2012;77:933-9 pubmed publisher
    Concentrations of serum estradiol-17? and progesterone were monitored in six female walruses using an enzyme immunoassay...
  34. Foote A, Hofreiter M, Morin P. Ancient DNA from marine mammals: studying long-lived species over ecological and evolutionary timescales. Ann Anat. 2012;194:112-20 pubmed publisher
    ..Finally, we highlight some of the problems of aDNA studies on marine mammals, such as obtaining sufficient sample sizes and calibrating for the marine reservoir effect when radiocarbon-dating such wide-ranging species...
  35. Lindqvist C, Roy T, Lydersen C, Kovacs K, Aars J, Wiig Ã, et al. Genetic diversity of historical Atlantic walruses (Odobenus rosmarus rosmarus) from Bjørnøya and Håøya (Tusenøyane), Svalbard, Norway. BMC Res Notes. 2016;9:112 pubmed publisher
    The population size of Atlantic walruses (Odobenus rosmarus rosmarus) is depleted relative to historical abundance levels...
  36. Davis R, Pierotti V, Lauer S, Hubl S, McLean J, Witztum J, et al. Lipoproteins in pinnipeds: analysis of a high molecular weight form of apolipoprotein E. J Lipid Res. 1991;32:1013-23 pubmed
    ..Thus, our studies have demonstrated that the higher apparent molecular weight of pinniped (sea lion) apoE is due to a longer polypeptide chain as well as posttranslational modification of the protein...
  37. Voinov V, Siniutin S, Siniutin E, Kavtsevich N, Zotov A. Method for studies of behavior and physiology of sea mammals. Bull Exp Biol Med. 2008;145:280-2 pubmed
    ..Results of pilot studies of behavioral activity and body systems of seals are presented...
  38. Kerr R. A warmer Arctic means change for all. Science. 2002;297:1490-3 pubmed
  39. Muir D, Born E, Koczansky K, Stern G. Temporal and spatial trends of persistent organochlorines in Greenland walrus (Odobenus rosmarus rosmarus). Sci Total Environ. 2000;245:73-86 pubmed
    ..The data for Greenland walrus from the 1970s and late 1980s provide a baseline for future trend monitoring in walrus...
  40. Nielsen O, Stewart R, Measures L, Duignan P, House C. A morbillivirus antibody survey of Atlantic walrus, narwhal and beluga in Canada. J Wildl Dis. 2000;36:508-17 pubmed
    A longitudinal serologic survey was conducted for morbillivirus antibodies in Atlantic walruses (Odobenus rosmarus rosmarus), narwhal (Monodon monoceros), and beluga (Delphinapterus leucas) from the Northwest Territories, Nunavut and the ..
  41. Noren S, Jay C, Burns J, Fischbach A. Rapid maturation of the muscle biochemistry that supports diving in Pacific walruses (Odobenus rosmarus divergens). J Exp Biol. 2015;218:3319-29 pubmed publisher
    ..We characterized age-specific dive limits of walruses by measuring anaerobic (acid-buffering capacity) and aerobic (myoglobin content) capacities of the muscles that ..
  42. Rideout B, Dosso S, Hannay D. Underwater passive acoustic localization of Pacific walruses in the northeastern Chukchi Sea. J Acoust Soc Am. 2013;134:2534-45 pubmed publisher
    ..A sequence of Pacific walrus vocalizations, recorded in the Chukchi Sea northwest of Alaska, is localized using this technique, yielding a track estimate and uncertainties with an estimated speed comparable to normal walrus swim speeds. ..
  43. Edwards H, Farwell D, Holder J, Lawson E. Fourier-transform Raman spectra of ivory. III: Identification of mammalian specimens. Spectrochim Acta A Mol Biomol Spectrosc. 1997;53A:2403-9 pubmed
    ..The results, which are obtained non-destructively from a variety of specimens, suggest that FT-Raman spectroscopy provides a potentially useful method for the identification of mammalian ivory...
  44. Schusterman R, Reichmuth C. Novel sound production through contingency learning in the Pacific walrus (Odobenus rosmarus divergens). Anim Cogn. 2008;11:319-27 pubmed
    b>Walruses (Odobenus rosmarus) are highly vocal amphibious mammals with a range of anatomical specializations that can provide plasticity to their sound emissions...
  45. Rausch R, George J, Brower H. Effect of climatic warming on the Pacific walrus, and potential modification of its helminth fauna. J Parasitol. 2007;93:1247-51 pubmed publisher
    ..Increased consumption of mammals or their remains by walruses may lead to a higher prevalence of trichinellosis in them and to more frequent occurrence in indigenous peoples ..
  46. Robards M, Burns J, Meek C, Watson A. Limitations of an optimum sustainable population or potential biological removal approach for conserving marine mammals: Pacific walrus case study. J Environ Manage. 2009;91:57-66 pubmed publisher
    ..Alternatively, walrus and other ice-associated pinnipeds will remain largely unmanaged during a period of profound environmental change...
  47. Franks B, Lyn H, Klein L, Reiss D. The influence of feeding, enrichment, and seasonal context on the behavior of Pacific Walruses (Odobenus rosmarus divergens). Zoo Biol. 2010;29:397-404 pubmed publisher
    Though some research exists concerning general behavior and activity patterns of Walruses in zoos or aquariums, less is known about how these patterns change in response to various environmental and temporal contexts...
  48. Riget F, Dietz R, Born E, Sonne C, Hobson K. Temporal trends of mercury in marine biota of west and northwest Greenland. Mar Pollut Bull. 2007;54:72-80 pubmed
    ..The annual changes in delta(15)N-adjusted [Hg] was estimated to -5.0% for the whole period and 2.2% during the last 5 years compared to -1.3% and 12.4%, respectively, for the non-adjusted [Hg]...
  49. Mouy X, Hannay D, Zykov M, Martin B. Tracking of Pacific walruses in the Chukchi Sea using a single hydrophone. J Acoust Soc Am. 2012;131:1349-58 pubmed publisher
    The vocal repertoire of Pacific walruses includes underwater sound pulses referred to as knocks and bell-like calls...
  50. Lento G, Hickson R, Chambers G, Penny D. Use of spectral analysis to test hypotheses on the origin of pinnipeds. Mol Biol Evol. 1995;12:28-52 pubmed publisher
    The evolutionary origin of the pinnipeds (seals, sea lions, and walruses) is still uncertain. Most authors support a hypothesis of a monophyletic origin of the pinnipeds from a caniform carnivore...
  51. Larrat S, Simard M, Lair S, Bélanger D, Proulx J. From science to action and from action to science: the Nunavik Trichinellosis Prevention Program. Int J Circumpolar Health. 2012;71:18595 pubmed publisher
    ..The objectives of the present communication are to review the NTPP, describe how science and action were interwoven in its development and identify its assets and limitations. Study design. Descriptive study...
  52. Oxtoby L, Horstmann L, Budge S, O Brien D, Wang S, Schollmeier T, et al. Resource partitioning between Pacific walruses and bearded seals in the Alaska Arctic and sub-Arctic. Oecologia. 2017;184:385-398 pubmed publisher
    ..of Arctic sea ice and primary production may alter benthic food webs that sustain populations of Pacific walruses (Odobenus rosmarus divergens) and bearded seals (Erignathus barbatus)...
  53. Boessenecker R, Churchill M. A reevaluation of the morphology, paleoecology, and phylogenetic relationships of the enigmatic walrus Pelagiarctos. PLoS ONE. 2013;8:e54311 pubmed publisher
    A number of aberrant walruses (Odobenidae) have been described from the Neogene of the North Pacific, including specialized suction-feeding and generalist fish-eating taxa...
  54. Melero M, García Párraga D, Corpa J, Ortega J, Rubio Guerri C, Crespo J, et al. First molecular detection and characterization of herpesvirus and poxvirus in a Pacific walrus (Odobenus rosmarus divergens). BMC Vet Res. 2014;10:968 pubmed publisher
    ..To date, however, genetic material of these viruses has not been detected in walrus (Odobenus rosmarus), another marine mammal of the Pinnipedia clade, even though anti-herpesvirus antibodies have been detected in these animals...
  55. Chechina O, Kovalenko I, Kulagina O, Mikhaĭlenko A. [Locomotion development of walruses Eumetopias Jubatus in early ontogenesis]. Zh Evol Biokhim Fiziol. 2004;40:55-9 pubmed
  56. Moorhead A, Grunenwald P, Dietz V, Schantz P. Trichinellosis in the United States, 1991-1996: declining but not gone. Am J Trop Med Hyg. 1999;60:66-9 pubmed
    ..The continued multiple case outbreaks and the identification of nonpork sources of infection indicate the need for further education and control measures...
  57. Zarnke R, Harder T, Vos H, Ver Hoef J, Osterhaus A. Serologic survey for phocid herpesvirus-1 and -2 in marine mammals from Alaska and Russia. J Wildl Dis. 1997;33:459-65 pubmed
    ..Antibody prevalence of PhHV-1 in walruses (Odobenus rosmarus) could be quantitatively predicted as a function of age...
  58. Andersen L, Born E, Gjertz I, Wiig O, Holm L, Bendixen C. Population structure and gene flow of the Atlantic walrus (Odobenus rosmarus rosmarus) in the eastern Atlantic Arctic based on mitochondrial DNA and microsatellite variation. Mol Ecol. 1998;7:1323-36 pubmed
    ..detected in the four samples were diagnostic for the NW Greenland sample, which implied that the group of walruses in this area is evolutionary distinct from walruses in the other three areas...
  59. Stoeva S, Kleinschmidt T. Proteolytic specificity of the neutral zinc proteinase from Bacillus mesentericus strain 76 determined by digestion of an alpha-globin chain. Biol Chem Hoppe Seyler. 1989;370:1139-43 pubmed
  60. Evans R, Richner P, Outridge P. Micro-spatial variations of heavy metals in the teeth of walrus as determined by laser ablation ICP-MS: the potential for reconstructing a history of metal exposure. Arch Environ Contam Toxicol. 1995;28:55-60 pubmed
    ..These data may suggest the most likely explanation for the currently high levels of some metals observed in certain Arctic marine mammals, i.e., natural phenomenon or anthropogenic contamination...
  61. Lin H, Kleinschmidt T, Johnson M, Braunitzer G. Carnivora: the primary structure of the Pacific Walrus (Odobenus rosmarus divergens, Pinnipedia) hemoglobin. Biol Chem Hoppe Seyler. 1989;370:135-40 pubmed
    ..Compared to Harbour Seal (Phoca vitulina) the Walrus hemoglobin shows 9 amino-acid replacements in the alpha-chains and 5 in the beta-chains. The relation between Pinnipedia and Arctoidea is discussed...
  62. Dubey J, Mergl J, Gehring E, Sundar N, Velmurugan G, Kwok O, et al. Toxoplasmosis in captive dolphins (Tursiops truncatus) and walrus (Odobenus rosmarus). J Parasitol. 2009;95:82-5 pubmed publisher
    ..1 and the walrus showed archetypal alleles consistent with infection by a Type II strain. No unique polymorphisms were detected. This is apparently the first report of isolation of T. gondii from a marine mammal in Canada. ..
  63. Sacchi L, Corona S, Gajadhar A, Pozio E. Ultrastructural characteristics of nurse cell-larva complex of four species of Trichinella in several hosts. Parasite. 2001;8:S54-8 pubmed
  64. Woodman S, Gibson A, García A, Contreras G, Rossen J, Werling D, et al. Structural characterisation of Toll-like receptor 1 (TLR1) and Toll-like receptor 6 (TLR6) in elephant and harbor seals. Vet Immunol Immunopathol. 2016;169:10-4 pubmed publisher
  65. Calle P, Seagars D, McClave C, Senne D, House C, House J. Viral and bacterial serology of free-ranging Pacific walrus. J Wildl Dis. 2002;38:93-100 pubmed
    ..Periodic screening of free-ranging populations for exposure to infectious diseases has become an important component of bio-monitoring programs to facilitate understanding and detecting trends in marine mammal populations...
  66. Heide Jørgensen M, Laidre K. Declining extent of open-water refugia for top predators in Baffin Bay and adjacent waters. Ambio. 2004;33:487-94 pubmed
    ..Potential consequences of reduced open-water for top marine predators include impacts on foraging efficiency and oxygen and prey availability...
  67. Butler D. Virtual globes: the web-wide world. Nature. 2006;439:776-8 pubmed
  68. Grebmeier J, Overland J, Moore S, Farley E, Carmack E, Cooper L, et al. A major ecosystem shift in the northern Bering Sea. Science. 2006;311:1461-4 pubmed
    ..These changes now observed on the shallow shelf of the northern Bering Sea should be expected to affect a much broader portion of the Pacific-influenced sector of the Arctic Ocean...
  69. Wolkers H, van Bavel B, Ericson I, Skoglund E, Kovacs K, Lydersen C. Congener-specific accumulation and patterns of chlorinated and brominated contaminants in adult male walruses from Svalbard, Norway: indications for individual-specific prey selection. Sci Total Environ. 2006;370:70-9 pubmed
    Blubber samples from 17 adult, male walruses were sampled in eastern Svalbard and analyzed for chlorinated and brominated contaminants...
  70. Tryland M, Lydersen C, Kovacs K, Thoresen S. Serum chemistry reference values in free-ranging north Atlantic male walruses (Odobenus rosmarus rosmarus) from the Svalbard archipelago. Vet Clin Pathol. 2009;38:501-6 pubmed publisher
    Information regarding health and disease is limited for walruses, a keystone species in arctic marine ecosystems...
  71. Vassetzky N, Kramerov D. CAN--a pan-carnivore SINE family. Mamm Genome. 2002;13:50-7 pubmed
    ..CAN structure is considered in the context of their function and evolution...
  72. Gruber A, Peters M, Knieriem A, Wohlsein P. Atherosclerosis with multifocal myocardial infarction in a Pacific walrus (Odobenus rosmarus divergens Illiger). J Zoo Wildl Med. 2002;33:139-44 pubmed
    ..The cause of the vascular lesions remains unknown. When compared with humans, atherosclerosis is rare in animals and has not been described in a walrus...
  73. Muraco H, Coombs L, Procter D, Turek P, Muraco M. Use of human chorionic gonadotropin in a male Pacific walrus (Odobenus rosmarus divergens) to induce rut and achieve a pregnancy in a nulliparous female. J Androl. 2012;33:789-97 pubmed
    ..Upon discontinuation of hCG treatment, the male resumed baseline testosterone levels. We theorize that the lack of synchronization of rut and ovulatory cycles is a primary reason for reproductive failure in these captive walrus...
  74. Locke M. Structure of ivory. J Morphol. 2008;269:423-50 pubmed
    ..Narwhals have the most abundant matrix particles with their radial/helical dentinal tubules having a twist opposite to that in the cementum...