| isolation of brucella species from cetaceans, seals and an otter. | brucella organisms which differed from the recognised species of the genus, were isolated from nine seals, eight cetaceans and one otter. a method is described for the isolation of brucella species from sea mammals and the first isolations of brucella species are recorded from an atlantic white-sided dolphin (lagenorhynchus acutus), two striped dolphins (stenella coeuleoalba), a hooded seal (cystophora cristata), a grey seal (halichoerus grypus) and a european otter (lutra lutra). there were dif ... | 1996 | 8799984 |
| epizootiology of morbillivirus infection in harp, hooded, and ringed seals from the canadian arctic and western atlantic. | using a virus neutralization technique, we found phocine distemper virus (pdv) antibody in 130 (83% of 157) harp seals (phoca groenlandica) from the western north atlantic sampled between 1988 and 1993 inclusive. in contrast, only 44 (24% of 185) hooded seals (cystophora cristata) had antibodies against pdv even though they were sympatric with harp seals and were sampled over a similar period, from 1989 to 1994 inclusive. antibodies occurred in 106 (41%) of 259 ringed seals (phoca hispida); this ... | 1997 | 9027686 |
| temporal trends in antibody production in captive grey, harp and hooded seals to a single administration immunocontraceptive vaccine. | the temporal production of antibody to a single-administration immunocontraceptive vaccine, known to be immunocontraceptive in free-ranging female grey seals (halichoerus grypus), was studied in captive grey seals, harp seals (phoca groenlandica) and hooded seals (cystophora cristata). the vaccine is based on liposome delivery of porcine zona pellucida antigens. when measured by antigen capture, the response of hooded and harp seals to the vaccine was similar to the response of grey seals. deter ... | 1997 | 9373858 |
| serosurvey of toxoplasma gondii in north atlantic marine mammals by the use of agglutination test employing whole tachyzoites and dithiothreitol. | serum samples from north atlantic populations of harp seal, phoca groenlandica (n = 316), ringed seal, phoca hispida (n = 48), hooded seal, cystophora cristata (n = 78), and minke whale, balaenoptera acutorostrata (n = 202), were tested for toxoplasma gondii-specific igg. the modified agglutination test (mat) was slightly modified to be more user-friendly by replacing the 0.2 m 2-mercaptoethanol with 10 mm dithiothreitol. no positive samples were found at 1:40 dilution. | 1998 | 9611681 |
| venous structures associated with thermoregulation of phocid seal reproductive organs. | seal reproductive systems are surrounded by thermogenic muscle and insulating blubber, suggesting elevated temperatures at the gonads and uterus. in the limbs of terrestrial mammals, cooled blood returning from superficial veins is mixed proximally with warm blood returning from deep veins. thus, mixed cool-superficial and warm-deep venous blood from the hind limbs is returned to the central circulation. | 1995 | 8579259 |
| genetic variation in the hooded seal, cystophora cristata, based on enzyme polymorphism and multi-locus dna fingerprinting. | the genetic population structure of hooded seal, cystophora cristata, was examined by electrophoretic analysis of allozymes and with multilocus dna fingerprinting. samples were collected in the jan mayen area and off newfoundland. allele products were resolved by isoelectric focusing. only five of 32 protein-coding loci investigated were polymorphic at the 95% level. the proportion of polymorphic loci was estimated to p = 0.233, and average heterozygosity to h = 0.047. tissue distribution, genot ... | 1994 | 7876031 |
| retrospective differentiation of canine distemper virus and phocine distemper virus in phocids. | formalin-fixed paraffin-embedded tissues from one caspian seal (phoca caspica), one harp seal (phoca groenlandica), one hooded seal (cystophora cristata), and one harbor seal (phoca vitulina vitulina) were used to compare the utility of immunohistochemistry (ihc) versus that of a novel seminested reverse transcriptase polymerase chain reaction (rt-pcr) to detect and differentiate canine distemper virus (cdv) and phocine distemper virus (pdv). four antibodies made against pdv were able to detect ... | 2004 | 15137488 |
| click sounds produced by cod (gadus morhua). | conspicuous sonic click sounds were recorded in the presence of cod (gadus morhua), together with either harp seals (pagophilus groenlandicus), hooded seals (cystophora cristata) or a human diver in a pool. similar sounds were never recorded in the presence of salmon (salmo salar) together with either seal species, or from either seal or fish species when kept separately in the pool. it is concluded that cod was the source of these sounds and that the clicks were produced only when cod were appr ... | 2004 | 15000203 |
| pineal and thyroid functions in newborn seals. | daily variations of pineal and plasma melatonin and plasma thyroid hormones were measured in harp seals (phoca groenlandica), grey seals (halichoerus grypus), and hooded seals (cystophora cristata), ranging in age from newborn to 14 days. in newborn harp seals the mean mass of the pineal gland was 273 mg (+/- 45 sem, n = 11), containing 49 ng (median) melatonin. in newborn, 4- and 10-day-old grey seals, the pineal mass was similar, weighing on average 337 mg (+/- 74, n = 6) and containing 90 ng ... | 1995 | 7628691 |
| genetic evidence for three species within pseudoterranova decipiens (nematoda, ascaridida, ascaridoidea) in the north atlantic and norwegian and barents seas. | genetic variation of 1017 specimens of codworm, pseudoterranova decipiens, collected from fish and seals at 23 sampling locations in the north atlantic and norwegian and barents seas, was analysed on the basis of 16 enzyme loci. three reproductively isolated species, provisionally designated p. decipiens a, b and c, were detected, showing distinct alleles at the following loci: mdh-1, 6pgdh, np, pgm, est-2 (between species a and b); mdh-3, 6pgdh, np, sod-1, adk, pgm, est-2, mpi (between a and c) ... | 1991 | 1869354 |
| the effect of hypercapnia on respiratory characteristics and diving behaviour of freely diving seals. | three trained young seals, one harp seal, pagophilus groenlandicus, and two hooded seals, cystophora cristata, have been used to study the effect of hypercapnia on respiratory characteristics and diving behaviour. the seals were allowed free movements within a circular pool, while diving and respiratory behaviour were recorded. during the experiments the alveolar co2 tension was continually recorded. there was a significant decrease in duration of dives with increasing paco2 for all animals. ve ... | 1976 | 935697 |
| perfluorinated chemicals infiltrate ocean waters: link between exposure levels and stable isotope ratios in marine mammals. | this is the first study to report on concentrations of perfluorinated organochemicals (focs) in marine mammals stranded along the southern north sea coast in relation to stable nitrogen and carbon isotope ratios (delta15n and delta13c). the presence of focs in top predators such as marine mammals would indicate a potential biomagnification of these compounds and their widespread occurrence. liver and kidney tissues of nine marine mammal species have been sampled. among all the measured focs comp ... | 2003 | 14717162 |
| melatonin potentiates the vasoconstrictive effect of noradrenaline in renal artery from newborn hooded seals (cystophora cristata) and harp seals (phoca groenlandica). | isometric tension was recorded by force displacement transducers in ring segments of the inferior branch of the renal artery from newborn hooded seals (cystophora cristata, n=6), harp seals (phoca groenlandica, n=3) and domestic pigs (sus scrofa f. domestica, n=5). arterial segments were mounted in heated organ baths and exposed to graded concentrations of noradrenaline (na) and adrenaline (a), alone or together with melatonin. the melatonin concentration in the bath was similar to the plasma co ... | 2001 | 11585261 |
| chemical characterisation of the oligosaccharides in hooded seal (cystophora cristata) and australian fur seal (arctocephalus pusillus doriferus) milk. | carbohydrates were extracted from hooded seal milk, crystophora cristata (family phocidae). free oligosaccharides were separated by gel filtration and then purified by ion exchange chromatography, gel filtration and preparative thin layer or paper chromatography and their structures determined by 1h-nmr. the hooded seal milk was found to contain inositol and at least nine oligosaccharides, most of which had lacto-n-neotetraose or lacto-n-neohexaose as core units, similar to those in milk of othe ... | 2001 | 11207444 |
| morbilliviral dermatitis in seals. | a juvenile female hooded seal (cystophora cristata) and a juvenile male harp seal (phoca groenlandica) stranded separately on the new jersey (usa) coast and were taken to a marine mammal rehabilitation center. both were lethargic and emaciated, had dermatitis, and died. histologic skin lesions in the seals were similar and consisted of epidermal and follicular epithelial hyperplasia, hyperkeratosis, degeneration, and necrosis. the most distinctive finding was extensive syncytial zones bounded su ... | 2001 | 11732810 |
| exostoses and cavernous venous formation in the external auditory canal of the hooded seal as a functional physiological organ. | exostoses of the external auditory canal (eac) develop after protracted mechanical, chemical or thermal irritation in particular. this is a common disorder among aquatic sportsmen and has been considered unique to man. we dissected and photodocumented the eacs of 5 newborn and 3 adult hooded seals (cystophora cristata). serial sections of the eacs were prepared for light microscopic evaluation after staining with haematoxylin-eosin or toluidine blue. all eacs exhibited a firm, broad-based. mount ... | 2000 | 11200588 |
| pcbs and ocps in male harbour, grey, harp and hooded seals from the estuary and gulf of st lawrence, canada. | blubber samples from adult male harbour seals (phoca vitulina) from the st lawrence estuary, and from grey (halichoerus grypus), harp (phoca groenlandica) and hooded (cystophora cristata) seals from the gulf of st lawrence, were analysed for polychlorinated biphenyls (pcb) and organochlorinated pesticides (ocp). all seals were between 5 and 19 years of age, and mean ages were not statistically different among the seal species. mean concentrations of sigmapcb and mirex were significantly higher i ... | 2002 | 12398323 |
| prevalence of brucella pinnipediae in healthy hooded seals (cystophora cristata) from the north atlantic ocean and ringed seals (phoca hispida) from svalbard. | investigations for brucella-infections were conducted in 29 hooded seals (cystophora cristata) caught between svalbard and greenland (north atlantic ocean; greenland sea) autumn 2002, and from 20 ringed seals (phoca hispida) caught in billefjord, svalbard, spring 2003. all animals were apparently healthy and were caught in their natural habitat. bacteriology on tissue samples from ringed seals was negative, whereas brucella sp. were recovered in tissues from 11 of the 29 hooded seals (38%), with ... | 2004 | 15627521 |
| an sem study of phocascaris cystophorae berland, 1964 (nematoda: anisakidae), a parasite of the hooded seal cystophora cristata. | scanning electron microscopy was used to study the surface morphological characteristics (excretory pore, interlabia knobs, lips and adjacent structures, caudal papillae and papilla-like structures) of the nematode phocascaris cystophorae, a parasite from the stomach of the hooded seal cystophora cristata. a comparative morphological analysis was made between species of phocascaris and contracaecum osculatum (sensu lato), which are all parasitic in phocid seals. | 2002 | 11912341 |
| levels of non-essential elements in muscle from harp seal (phagophilus groenlandicus) and hooded seal (cystophora cristata) caught in the greenland sea area. | the non-essential elements, arsenic, cadmium, mercury and lead, inevitably accumulate in marine top predators such as seals. the concentration of these elements and the essential element selenium, due to its proposed protective properties against mercury toxicity in marine mammals, were measured in muscle, liver and kidney from reproductive active females of harp seal (phagophilus groenlandicus) and hooded seal (cystophora cristata) caught in the drift ice between iceland and east greenland. ars ... | 2006 | 16368127 |
| seroprevalence of toxoplasma gondii in canadian pinnipeds. | sera (n = 328) collected from phocids (1995-97) from the east coast of canada, including harp seals (phoca groenlandica), hooded seals (cystophora cristata), grey seals (halichoerus grypus), and harbor seals (phoca vitulina), were diluted 1:25, 1:50, and 1:500 and tested by a modified agglutination test for antibodies to toxoplasma gondii. titers equal to or greater than 1:25 were considered evidence of exposure. grey seal (11/122, 9%), harbor seal (3/34, 9%), and hooded seal (1/60, 2%) had tite ... | 2004 | 15362830 |
| serological investigation of virus infections in harp seals (phoca groenlandica) and hooded seals (cystophora cristata). | | 1994 | 8073595 |
| tris (4-chlorophenyl) methane and tris (4-chlorophenyl) methanol in marine mammals from the estuary and gulf of st. lawrence. | levels of tris (4-chlorophenyl) methanol (tcpm) and its presumed precursor tris (4-chlorophenyl) methane (tcpme) are reported in marine mammals from the estuary and gulf of st. lawrence, canada. these compounds were measured in blubber samples of seals and whales using ion trap mass spectrometry (ms/ms) detection. detectable concentrations of both tcpm and tcpme were observed in all of the samples analysed. concentrations of these compounds varied with species ranging from 1.7 to 153 and from 1. ... | 2001 | 11202713 |
| evidence of brucella infection in marine mammals in the north atlantic ocean. | between 1983 and 1996 a total of 1386 samples of serum were taken from four species of seal and three species of whale in the waters west of iceland, the area of pack-ice north-west of jan mayen, the northern coast of norway and the kola peninsula, the waters west of svalbard, and the barents sea; they were tested for the presence of anti-brucella antibodies with an indirect elisa (protein g conjugate). the positive sera were re-tested with classical brucellosis serological tests, such as the se ... | 1999 | 10378290 |
| clostridium perfringens toxin types in hooded seals in the greenland sea, determined by pcr and elisa. | very little is known about the occurrence of clostridium perfringens and of diseases caused by this anaerobic bacterium in marine mammals, especially those that are free-living. during a scientific expedition to the greenland sea (west ice) in spring 1999, faeces samples from 70 hooded seals (cystophora cristata) were taken to isolate c. perfiringens. subsequently, pcr analysis of the isolates was performed with oligonucleotide primers of the genes encoding the four major lethal toxins (alpha, b ... | 2001 | 11846022 |
| hematology and serum chemistry of harp (phoca groenlandica) and hooded seals (cystophora cristata) during the breeding season, in the gulf of st. lawrence, canada. | standard hematologic and serum chemistry parameters were determined from 28 harp seals (phoca groenlandica) and 20 hooded seals (cystophora cristata) sampled from 6 march 2001 to 13 march 2001 during the breeding season. whole blood was collected immediately postmortem from harp seal mother-pup pairs and from six hooded seal pups, and from live-captured adult hooded seals and three hooded seal pups; blood was analyzed within 24 hr at a local human hospital. a certified veterinary laboratory vali ... | 2006 | 16699154 |
| comparative pathology of nocardiosis in marine mammals. | nocardia spp. infections in mammals cause pyogranulomatous lesions in a variety of organs, most typically the lung. members of the nocardia asteroides complex are the most frequently recognized pathogens. nine cases of nocardiosis in free-ranging pinnipeds and 10 cases of nocardiosis in cetaceans were evaluated. host species included the hooded seal (cystophora cristata, n = 8), leopard seal (hydrurga leptonyx, n = 1), atlantic bottlenose dolphin (tursiops truncatus, n = 4), beluga whale (delphi ... | 2009 | 19261643 |
| effects of suckling and the postsuckling fast on weights of the body and internal organs of harp and hooded seal pups. | the weights of harp seal pups quadruple during 13 days of suckling while hooded seal pups double in weight in a lactation period of just 4 days. pups of both species then fast for a month or longer. as a first measure of tissue responses to this 'feast and famine' pattern, we weighted the body, sculp (blubber and attached skin), core (carcass including viscera) and major internal organs of seal pups at birth, at the end of suckling, and at the end of the fast. when expressed as a percentage of b ... | 1989 | 2605282 |
| development of myoglobin concentration and acid buffering capacity in harp (pagophilus groenlandicus) and hooded (cystophora cristata) seals from birth to maturity. | pinnipeds rely on muscle oxygen stores to help support aerobic diving, therefore muscle maturation may influence the behavioral ecology of young pinnipeds. to investigate the pattern of muscle development, myoglobin concentration ([mb]) and acid buffering ability (beta) was measured in ten muscles from 23 harp and 40 hooded seals of various ages. adult [mb] ranged from 28-97 to 35-104 mg g tissue(-1) in harp and hooded seals, respectively, with values increasing from the cervical, non-swimming m ... | 2009 | 19565249 |
| a molecular view of pinniped relationships with particular emphasis on the true seals. | phylogenetic analysis of conservative nucleotide substitutions in 18 complete sequences of the mitochondrial cytochrome b gene of phocidae (true seals), odobenidae (walruses), and otariidae (sea lions and fur seals), plus three ursid and three felid sequences, identified the pinnipeds as monophyletic with otariidae and odobenidae on a common evolutionary branch. analysis of total nucleotide differences separated the evolutionary lineages of northern and southern phocids. both lineages are distin ... | 1995 | 7714914 |
| mlva-16 typing of 295 marine mammal brucella isolates from different animal and geographic origins identifies 7 major groups within brucella ceti and brucella pinnipedialis. | since 1994, brucella strains have been isolated from a wide range of marine mammals. they are currently recognized as two new brucella species, b. pinnipedialis for the pinniped isolates and b. ceti for the cetacean isolates in agreement with host preference and specific phenotypic and molecular markers. in order to investigate the genetic relationships within the marine mammal brucella isolates and with reference to terrestrial mammal brucella isolates, we applied in this study the multiple loc ... | 2009 | 19619320 |
| identification of novel dna fragments and partial sequence of a genomic island specific of brucella pinnipedialis. | since the 1990s, brucella strains have been isolated from a wide variety of marine mammals and were recently recognized as two different species, i.e. brucella pinnipedialis for pinniped isolates and brucella ceti for cetacean isolates. the aim of this study was to identify specific dna fragments of marine mammal brucella strains using a previously described infrequent restriction site-pcr (irs-pcr) method but with three new couples of restriction enzymes applied on a larger panel of marine mamm ... | 2008 | 18514443 |
| a review of brucella infection in marine mammals, with special emphasis on brucella pinnipedialis in the hooded seal (cystophora cristata). | abstract: brucella spp. were isolated from marine mammals for the first time in 1994. two novel species were later included in the genus; brucella ceti and brucella pinnipedialis, with cetaceans and seals as their preferred hosts, respectively. brucella spp. have since been isolated from a variety of marine mammals. pathological changes, including lesions of the reproductive organs and associated abortions, have only been registered in cetaceans. the zoonotic potential differs among the marine m ... | 2011 | 21819589 |
| comparison of toxaphene congeners levels in five seal species from eastern canada: what is the importance of biological factors? | environmentally relevant chlorobornanes (chbs) were measured in blubber samples of harbor (phoca vitulina), gray (halichoerus grypus), harp (phoca groenlandica), and hooded seals (cystophora cristata) sampled in different part of the st. lawrence marine ecosystem (slme) and ringed seals (phoca hispida) sampled in the eastern canadian arctic waters. the purpose of this study was to compare the levels of six chbs (parlar-26, -40/-41, -44, -50, and -62) among the five seal species. seal species cou ... | 2005 | 15819196 |
| how many seals were there? the global shelf loss during the last glacial maximum and its effect on the size and distribution of grey seal populations. | predicting how marine mammal populations respond to habitat changes will be essential for developing conservation management strategies in the 21st century. responses to previous environmental change may be informative in the development of predictive models. here we describe the likely effects of the last ice age on grey seal population size and distribution. we use satellite telemetry data to define grey seal foraging habitat in terms of the temperature and depth ranges exploited by the contem ... | 2012 | 23300843 |
| giardia and cryptosporidium in harp and hooded seals from the gulf of st. lawrence, canada. | giardia and cryptosporidium are protozoan parasites known to cause enteric disease in terrestrial wildlife species (mammals, reptiles and birds). few surveys for giardia and cryptosporidium in marine wildlife species, such as pinnipeds, have been reported. the objective of this study was to determine the prevalence and genotype of giardia and cryptosporidium in two species of pinnipeds, harp seal (phoca groenlandica) and hooded seal (cystophora cristata), from the gulf of st. lawrence, canada. f ... | 2010 | 20594649 |
| entrance and survival of brucella pinnipedialis hooded seal strain in human macrophages and epithelial cells. | marine mammal brucella spp. have been isolated from pinnipeds (b. pinnipedialis) and cetaceans (b. ceti) from around the world. although the zoonotic potential of marine mammal brucellae is largely unknown, reports of human disease exist. there are few studies of the mechanisms of bacterial intracellular invasion and multiplication involving the marine mammal brucella spp. we examined the infective capacity of two genetically different b. pinnipedialis strains (reference strain; ntct 12890 and a ... | 2013 | 24376851 |
| underwater sounds of pinnipeds. | descriptions and analyses are presented of underwater sounds made by six species of seals in captivity, zalophus californianus, phoca vitulina, p. (pusa) hispida, p. (pagophilus) groenlandica, halichoerus grypus, and cystophora cristata. the suitability of these very faint sounds for echolocation is discussed. | 1963 | 17742884 |
| marine mammal brucella isolates with different genomic characteristics display a differential response when infecting human macrophages in culture. | marine mammal brucella strains with different genomic characteristics according to distribution of is711 elements in their genomes were analysed for their intracellular behaviour in human thp-1 macrophage-like cells. seven different groups of marine mammal strains were identified including a human isolate from new zealand presumably from marine origin. entry and intracellular survival of strains representative of these groups in thp-1 human macrophage-like cells were analysed at several times of ... | 2009 | 19397885 |
| experimental challenge of atlantic cod (gadus morhua) with a brucella pinnipedialis strain from hooded seal (cystophora cristata). | pathology has not been observed in true seals infected with brucella pinnipedialis. a lack of intracellular survival and multiplication of b. pinnipedialis in hooded seal (cystophora cristata) macrophages in vitro indicates a lack of chronic infection in hooded seals. both epidemiology and bacteriological patterns in the hooded seal point to a transient infection of environmental origin, possibly through the food chain. to analyse the potential role of fish in the transmission of b. pinnipediali ... | 2016 | 27415626 |
| some morphological characteristics of dipetalonema spirocauda leidy, 1858, isolated from the hooded seal, cystophora cristata erxleben 1777. | | 1973 | 4734545 |
| entry and elimination of marine mammal brucella spp. by hooded seal (cystophora cristata) alveolar macrophages in vitro. | a high prevalence of brucellapinnipedialis serology and bacteriology positive animals has been found in the northeast atlantic stock of hooded seal (cystophoracristata); however no associated gross pathological changes have been identified. marine mammal brucellae have previously displayed different infection patterns in human and murine macrophages. to investigate if marine mammal brucella spp. are able to invade and multiply in cells originating from a presumed host species, we infected alveol ... | 2013 | 23936159 |
| brucella pinnipedialis in hooded seal (cystophora cristata) primary epithelial cells. | marine brucella spp. have been isolated from numerous pinniped and cetacean species, but pathological findings in association with infection with brucella pinnipedialis in pinnipeds have been sparse. the capacity of brucellae to survive and replicate within host macrophages underlies their important ability to produce chronic infections, but previous work has shown that b. pinnipedialis spp. are rapidly eliminated from hooded seal (cystophora cristata) alveolar macrophages. | 2015 | 26809981 |
| remarkable neuronal hypoxia tolerance in the deep-diving adult hooded seal (cystophora cristata). | seals cope with regular exposure to diving hypoxia by storing oxygen in blood and skeletal muscles and by limiting the distribution of blood-borne oxygen to all but the most hypoxia vulnerable tissues (brain, heart), through dramatic cardiovascular adjustments. still, arterial oxygen tension of freely diving seals regularly drops to levels that would be fatal to most non-diving mammals. some cerebral protection is offered through diving-induced brain cooling and, possibly, enhanced oxygen delive ... | 2008 | 18824079 |
| brucella pinnipedialis hooded seal (cystophora cristata) strain in the mouse model with concurrent exposure to pcb 153. | brucellosis, a worldwide zoonosis, is linked to reproductive problems in primary hosts. a high proportion of brucella-positive hooded seals (cystophora cristata) have been detected in the declined northeast atlantic stock. high concentrations of polychlorinated biphenyls (pcbs) have also been discovered in top predators in the arctic, including the hooded seal, pcb 153 being most abundant. the aim of this study was to assess the pathogenicity of brucella pinnipedialis hooded seal strain in the m ... | 2014 | 24534631 |
| tissue-specific contaminant accumulation and associated effects on hepatic serum analytes and cytochrome p450 enzyme activities in hooded seals (cystophora cristata) from the gulf of st. lawrence. | the current study aims to assess contaminant levels and tissue burdens in hooded seal (cystophora cristata) blubber, liver, and blood in association with cytochrome p450 (cyp) enzymes (cyp1a and -3a) and serum analytes (hepatic enzymes like alanine aminotransferase [alt], aspartate aminotransferase, alkaline phosphatase [ap], and gamma-glutamyltransferase [ggt], serum proteins, and creatine kinase). contaminant accumulation levels and patterns of polychlorinated biphenyls, chlorinated pesticides ... | 2009 | 18626617 |
| DETECTION OF CRYPTOSPORIDIUM SP. SEAL IN TWO NEW SEAL SPECIES, PHOCA VITULINA AND CYSTOPHORA CRISTATA AND A NOVEL CRYPTOSPORIDIUM GENOTYPE IN A THIRD SEAL SPECIES, PAGOPHILUS GROENLANDICUS FROM THE GULF OF MAINE. | Abstract Data on the geographic distribution and host-specificity of Cryptosporidium spp. are critical for developing an understanding of likely transmission patterns in nature. During a molecular based survey of fecal samples from 293 terrestrial and aquatic animals in Maine, we detected Cryptosporidium sp. in 11 harbor seals, 1 hooded seal, and 1 harp seal. None of the terrestrial or freshwater mammal fecal samples or bird samples tested positive for Cryptosporidium sp. However, the seque ... | 2011 | 22017467 |
| when the brain goes diving: transcriptome analysis reveals a reduced aerobic energy metabolism and increased stress proteins in the seal brain. | during long dives, the brain of whales and seals experiences a reduced supply of oxygen (hypoxia). the brain neurons of the hooded seal (cystophora cristata) are more tolerant towards low-oxygen conditions than those of mice, and also better survive other hypoxia-related stress conditions like a reduction in glucose supply and high concentrations of lactate. little is known about the molecular mechanisms that support the hypoxia tolerance of the diving brain. | 2016 | 27507242 |
| vitamin d metabolism in the hooded seal (cystophora cristata). | fish-eating mammals, such as seals, appear to ingest levels of vitamin d that are toxic to most mammals. to determine how seals cope with high vitamin d intakes, the metabolism of tritiated cholecalciferol ([3h]d3) was investigated in hooded seal (cystophora cristata) pups during their postweaning fast and pups and adults consuming herring alone or supplemented with 400,000 iu d3 daily. [3h]d3 was metabolized to 25-[3h]ohd3 and 24,25-[3h](oh)2d3. 1,25-[3h](oh)2d3 was not detected, but plasma lev ... | 2010 | 2832569 |
| when the brain goes diving: glial oxidative metabolism may confer hypoxia tolerance to the seal brain. | deep diving mammals have developed strategies to cope with limited oxygen availability when submerged. these adaptations are associated with an increased neuronal hypoxia tolerance. brain neurons of the hooded seal cystophora cristata remain much longer active in hypoxic conditions than those of mice. to understand the cellular basis of neuronal hypoxia tolerance, we studied neuroglobin and cytochrome c in c. cristata brain. neuroglobin, a respiratory protein typically found in vertebrate neuron ... | 2009 | 19576963 |
| phenotypic and molecular characterisation of brucella isolates from marine mammals. | bacteria of the genus brucella are the causative organisms of brucellosis in animals and man. previous characterisation of brucella strains originating from marine mammals showed them to be distinct from the terrestrial species and likely to comprise one or more new taxa. recently two new species comprising brucella isolates from marine mammals, b. pinnipedialis and b. ceti, were validly published. here we report on an extensive study of the molecular and phenotypic characteristics of marine mam ... | 2008 | 19091076 |
| the use of non destructive biomarkers in the study of marine mammals. | marine mammals have been subject to heavy anthropogenic pressure by direct killing and chemical pollution all over the world. most studies of contamination and biomarker responses in marine mammals have been conducted using animals killed by hunting out of a total of 12 cetacean species studied, 45 of the specimens were obtained by sacrificing the animal; out of a total of eight pinniped species studied, 40 of the specimens were obtained by killing. the development of a series of non destructive ... | 1997 | 23899212 |
| polychlorinated naphthalenes (pcns) in sub-arctic and arctic marine mammals, 1986-2009. | a selection of pcn congeners was analyzed in pooled blubber samples of pilot whale (globicephala melas), ringed seal (phoca hispida), minke whale (balaenoptera acutorostrata), fin whale (balaenoptera physalus), harbour porpoise (phocoena phocoena), hooded seal (cystophora cristata) and atlantic white-sided dolphin (lagenorhynchus acutus), covering a time period of more than 20 years (1986-2009). a large geographical area of the north atlantic and arctic areas was covered. pcn congeners 48, 52, 5 ... | 2012 | 22356752 |
| methoxylated polybrominated diphenyl ethers (meo-pbdes) are major contributors to the persistent organobromine load in sub-arctic and arctic marine mammals, 1986-2009. | a selection of meo-bde and bde congeners were analyzed in pooled blubber samples of pilot whale (globicephala melas), ringed seal (phoca hispida), minke whale (balaenoptera acutorostrata), fin whale (balaenoptera physalus), harbor porpoise (phocoena phocoena), hooded seal (cystophora cristata), and atlantic white-sided dolphin (lagenorhynchus acutus), covering a time period of more than 20 years (1986-2009). the analytes were extracted and cleaned-up using open column extraction and multi-layer ... | 2012 | 22225820 |
| polybrominated diphenyl ethers (pbdes) in marine mammals from arctic and north atlantic regions, 1986-2009. | a selection of pbde congeners was analyzed in pooled blubber samples of pilot whale (globicephala melas), ringed seal (phoca hispida), minke whale (balaenoptera acutorostrata), fin whale (balaenoptera physalus), harbor porpoise (phocoena phocoena), hooded seal (cystophora cristata) and atlantic white-sided dolphin (lagenorhynchus acutus), covering a time period of more than 20 years (1986-2009). the analytes were extracted and cleaned-up using open column extraction and multi-layer silica gel co ... | 2012 | 21802148 |
| chlorinated hydrocarbon contaminants in arctic marine mammals. | by 1976, the presence of chlorinated hydrocarbon contaminants (chcs) had been demonstrated in fur seal (callorhinus ursinus), ringed seal (phoca hispida), hooded seal (cystophora cristata), bearded seal (erignathus barbatus), walrus (obdobenus rosmarus divergens), beluga (delphinapterus leucas), porpoise (phocoena phocoena) and polar bear (ursus maritimus) in various parts of the arctic. in spite of this early interest, very little subsequent research on contaminants in arctic marine mammals was ... | 1994 | 7973601 |
| increasing levels of long-chain perfluorocarboxylic acids (pfcas) in arctic and north atlantic marine mammals, 1984-2009. | temporal variations in concentrations of perfluorinated carboxylic acids (pfcas) and sulfonic acids (pfsas), including perfluorooctane sulfonate (pfos) and perfluorooctanoate (pfoa) structural isomers, were examined in livers of pilot whale (globicephala melas), ringed seal (phoca hisida), minke whale (balaenoptera acutorostrata), harbor porpoise (phocoena phocoena), hooded seal (cystophora cristata), atlantic white-sided dolphin (lagenorhynchus acutus) and in muscle tissue of fin whales (balaen ... | 2012 | 22051347 |
| a retrospective survey of the ocular histopathology of the pinniped eye with emphasis on corneal disease. | a retrospective review of globes from 70 pinnipeds submitted to the comparative ocular pathology laboratory of wisconsin (coplow) describing the type and frequency of ocular disease. | 2013 | 22812701 |
| maternal transfer of perfluoroalkyl substances in hooded seals. | the role of milk in the transfer of perfluoroalkyl substances (pfass) to offspring is not well known in wildlife. eight pfass were quantified in plasma and milk in mother-pup pairs of hooded seals (cystophora cristata) during the nursing period, and the role of milk in the transfer process was analyzed. hooded seal was chosen because of its short lactation period (3-4 d), during which the pup feeds only on milk. placental or lactation transfer would thus be the only source of pfas in the pup. of ... | 2017 | 27771942 |
| an atypical distribution of lactate dehydrogenase isoenzymes in the hooded seal (cystophora cristata) brain may reflect a biochemical adaptation to diving. | the brains of some diving mammals can withstand periods of severe hypoxia without signs of deleterious effects. this may in part be due to an enhanced cerebral capacity for anaerobic energy production. here, we have tested this hypothesis by comparing various parameters of the lactate dehydrogenase (ldh) in the brain of the hooded seal (cystophora cristata) with those in the brains of the ferret (mustela putorius furo) and mouse (mus musculus). we found that mrna and protein expression of lactat ... | 2016 | 26820264 |
| pinniped phylogeny and a new hypothesis for their origin and dispersal. | the relationships and the zoogeography of the three extant pinniped families, otariidae (sea lions and fur seals), odobenidae (one extant species, the walrus), and phocidae (true seals), have been contentious. here, we address these topics in a molecular study that includes all extant species of true seals and sea lions, four fur seals and the walrus. contrary to prevailing morphological views the analyses conclusively showed monophyletic pinnipedia with a basal split between otarioidea (otariid ... | 2006 | 16815048 |
| systemic mucormycosis in a hooded seal (cystophora cristata). | a 4-yr-old male captive hooded seal (cystophora cristata), previously diagnosed as hypothyroid, died after a 3-wk period of lethargy and inappetance despite treatment that included intramuscular administration of antibiotics and multivitamins. gross pathologic findings included extensive muscle necrosis over the left flank, an underlying necrotic iliac lymph node, two necrotic pulmonary masses and a necrotic bronchial lymph node. routine cultures yielded a number of bacterial isolates and a heav ... | 2011 | 22946418 |
| 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 |
| levels and patterns of hydroxylated polychlorinated biphenyls (oh-pcbs) and their associations with thyroid hormones in hooded seal (cystophora cristata) mother-pup pairs. | blood (plasma/serum) samples from 14 adult female and their pups (1-4 days old) captured in the west ice, east of greenland were analysed for concentrations of total and free thyroxine and triiodothyronine (tt4, ft4, tt3, ft3), and hydroxylated polychlorinated biphenyls (oh-pcbs). the levels of all thyroid hormones (ths) were significantly higher in pups than in mothers. sum oh-pcb levels (σoh-pcbs: 4-oh-cb107, 3'-oh-cb138, 4-oh-cb146, 4'-oh-cb172, 4-oh-cb187) were significantly higher in mother ... | 2011 | 21888873 |
| a comparative morphometric analysis of three cranial nerves in two phocids: the hooded seal (cystophora cristata) and the harbor seal (phoca vitulina). | while our knowledge about the senses of pinnipeds has increased over the last decades almost nothing is known about the organization of the neuroanatomical pathways. in a first approach to this field of research, we assessed the total number of myelinated axons of three cranial nerves (cns) in the harbor (phoca vitulina, pv) and hooded seal (cystophora cristata, cc). axons were counted in semithin sections of the nerves embedded in epon and stained with toluidine blue. in both species, the highe ... | 2016 | 26643122 |
| the eyes of the deep diving hooded seal (cystophora cristata) enhance sensitivity to ultraviolet light. | the mammalian visual range is approximately 400-700 nm, although recent evidence suggests varying ultraviolet (uv) extensions in diverse terrestrial species. uv sensitivity may have advantages in the dim, blue light shifted environment experienced by submerged marine mammals. it may also be advantageous when seals are on land as uv is reflected by snow and ice but absorbed by fur, enhancing visual contrast. here we show that the pelagic hooded seal (cystophora cristata) has a highly uv permissiv ... | 2015 | 25964660 |
| synaptic transmission despite severe hypoxia in hippocampal slices of the deep-diving hooded seal. | brain neurons of the deep-diving hooded seal (cystophora cristata) are known to be inherently hypoxia tolerant. here, we have used in vitro field potential recordings in hippocampal slices to compare effects of severe hypoxia on synaptic transmission in hooded seals vs. non-diving mammals. synaptic responses of mice (mus musculus) to hypoxia were in accordance with previously published data. hippocampal slices of reindeer (rangifer tarandus), an alternative large-mammal non-diving model, behaved ... | 2016 | 27480049 |
| a protein a/g indirect enzyme-linked immunosorbent assay for the detection of anti-brucella antibodies in arctic wildlife. | a species-independent indirect enzyme-linked immunosorbent assay (ielisa) based on chimeric protein a/g was established for the detection of anti-brucella antibodies in arctic wildlife species and compared to previously established brucellosis serological tests for hooded seals (cystophora cristata), minke whales (balaenoptera acutorostrata), sei whales (balaenoptera borealis), fin whales (balaenoptera physalus), and polar bears (ursus maritimus), as well as bacteriology results for reindeer and ... | 2013 | 23572454 |
| marine mammal strandings and environmental changes: a 15-year study in the st. lawrence ecosystem. | understanding the effects of climatic variability on marine mammals is challenging due to the complexity of ecological interactions. we used general linear models to analyze a 15-year database documenting marine mammal strandings (1994-2008; n = 1,193) and nine environmental parameters known to affect marine mammal survival, from regional (sea ice) to continental scales (north atlantic oscillation, nao). stranding events were more frequent during summer and fall than other seasons, and have incr ... | 2013 | 23544059 |
| neuroglobin of seals and whales: evidence for a divergent role in the diving brain. | although many physiological adaptations of diving mammals have been reported, little is known about how their brains sustain the high demands for metabolic energy and thus o(2) when submerged. a recent study revealed in the deep-diving hooded seal (cystophora cristata) a unique shift of the oxidative energy metabolism and neuroglobin, a respiratory protein that is involved in neuronal hypoxia tolerance, from neurons to astrocytes. here we have investigated neuroglobin in another pinniped species ... | 2012 | 22864183 |
| preparing muscles for diving: age-related changes in muscle metabolic profiles in harp (pagophilus groenlandicus) and hooded (cystophora cristata) seals. | in adult marine mammals, muscles can sustain aerobic metabolism during dives in part because they contain large oxygen (o2) stores and metabolic rates are low. however, young pups have significantly lower tissue o2 stores and much higher mass-specific metabolic rates. to investigate how these differences may influence muscle function during dives, we measured the activities of enzymes involved in aerobic and anaerobic metabolic pathways (citrate synthase [cs], β-hydroxyacyl-coenzyme a dehydrogen ... | 2015 | 25730272 |
| 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 |
| the role of glycogen, glucose and lactate in neuronal activity during hypoxia in the hooded seal (cystophora cristata) brain. | the brains of diving mammals are repeatedly exposed to hypoxic conditions during diving. brain neurons of the hooded seal (cystophora cristata) have been shown to be more hypoxia tolerant than those of mice, but the underlying mechanisms are not clear. here we investigated the roles of different metabolic substrates for maintenance of neuronal activity and integrity, by comparing the in vitro spontaneous neuronal activity of brain slices from layer v of the visual cortex of hooded seals with tho ... | 2014 | 24959743 |
| investigating annual diving behaviour by hooded seals (cystophora cristata) within the northwest atlantic ocean. | with the exception of relatively brief periods when they reproduce and moult, hooded seals, cystophora cristata, spend most of the year in the open ocean where they undergo feeding migrations to either recover or prepare for the next fasting period. valuable insights into habitat use and diving behaviour during these periods have been obtained by attaching satellite relay data loggers (srdls) to 51 northwest (nw) atlantic hooded seals (33 females and 18 males) during ice-bound fasting periods (2 ... | 2013 | 24282541 |
| age-dependent prevalence of anti-brucella antibodies in hooded seals cystophora cristata. | investigations of hooded seals cystophora cristata have revealed high prevalences of brucella-positive seals in the reduced northeast atlantic stock, compared to the increasing northwest atlantic stock. this study evaluated the relation between brucella-serostatus in seals in the northeast atlantic stock and age, sex, body condition and reproduction. bacteriology documented which animals and organs were b. pinnipedialis positive. no relationship was observed between brucella-serostatus and body ... | 2013 | 24191996 |
| effects of complex organohalogen contaminant mixtures on thyroid homeostasis in hooded seal (cystophora cristata) mother-pup pairs. | many lipid-soluble and phenolic compounds present in the complex mixture of orgaohalogen contaminants (ohcs) that arctic wildlife is exposed to have the ability to interfere with the thyroid hormone (th) system. the aim of this study was to identify compounds that might interfere with thyroid homeostasis in 14 nursing hooded seal (cystophora cristata) mothers and their pups (1-4d old) sampled in the west ice in march 2008. multivariate modelling was used to assess the potential effects of measur ... | 2013 | 23726007 |
| paternity exclusion by dna fingerprinting, and mate guarding in the hooded seal cystophora cristata. | hooded seal cystophora cristata trios consist of an adult female, her pup, and an attending adult male. using dna fingerprinting, we excluded the possibility that the attending males within hooded seal trios were the fathers of the pups, proving that these hooded seals did not remain paired from one breeding season to the next. behavioural observations of the trios after capture and release revealed that male hooded seals displace one another in attending nursing females. mate guarding appears t ... | 1994 | 8019687 |
| rapid postnatal development of myoglobin from large liver iron stores in hooded seals. | hooded seals (cystophora cristata) rely on large stores of oxygen, either bound to hemoglobin or myoglobin (mb), to support prolonged diving activity. pups are born with fully developed hemoglobin stores, but their mb levels are only 25-30% of adult levels. we measured changes in muscle [mb] from birth to 1 year of age in two groups of captive hooded seal pups, one being maintained in a seawater pool and one on land during the first 2 months. all pups fasted during the first month, but were fed ... | 2013 | 23348948 |
| what are the toxicological effects of mercury in arctic biota? | this review critically evaluates the available mercury (hg) data in arctic marine biota and the inuit population against toxicity threshold values. in particular marine top predators exhibit concentrations of mercury in their tissues and organs that are believed to exceed thresholds for biological effects. species whose concentrations exceed threshold values include the polar bears (ursus maritimus), beluga whale (delphinapterus leucas), pilot whale (globicephala melas), hooded seal (cystophora ... | 2013 | 23231888 |
| selective brain cooling and its vascular basis in diving seals. | brain (t(brain)), intra-aorta (t(aorta)), latissimus dorsi muscle (t(m)) and rectal temperature (t(r)) were measured in harp (pagophilus groenlandicus) and hooded (cystophora cristata) seals during experimental dives in 4 degrees c water. the median brain cooling was about 1 degrees c during 15 min diving, but in some cases it was as much as 2.5 degrees c. cooling rates were slow for the first couple of minutes, but increased significantly after about 5 min of diving. the onset of cooling someti ... | 2010 | 20639422 |
| liquid chromatographic enantioseparation of the brominated flame retardant 2,3-dibromopropyl-2,4,6-tribromophenyl ether (dpte) and enantiomer fractions in seal blubber. | enantioselective analyses of the chiral brominated flame retardant 2,3-dibromopropyl-2,4,6-tribromophenyl ether (dpte) are the focus of this work. high performance liquid chromatography (hplc) equipped with a column that had a chiral stationary phase consisting of a modified cellulose derivative allowed for the fractionation of the enantiomers of dpte. the enantiomeric excess was 98.2% for enantiomer 1 and 99% for enantiomer 2. polarimetric measurements verified that the first eluting enantiomer ... | 2010 | 19863996 |
| transcriptome analysis identifies key metabolic changes in the hooded seal (cystophora cristata) brain in response to hypoxia and reoxygenation. | the brain of diving mammals tolerates low oxygen conditions better than the brain of most terrestrial mammals. previously, it has been demonstrated that the neurons in brain slices of the hooded seal (cystophora cristata) withstand hypoxia longer than those of mouse, and also tolerate reduced glucose supply and high lactate concentrations. this tolerance appears to be accompanied by a shift in the oxidative energy metabolism to the astrocytes in the seal while in terrestrial mammals the aerobic ... | 2017 | 28046118 |
| hypoxia in freely diving hooded seal, cystophora cristata. | | 1976 | 9243 |
| the respiratory properties of the blood of the bladdernose seal (cystophora cristata). | | 1969 | 5809093 |
| [the larynx of the hood seal (cystophora cristata erxleben 1777). a further contribution to the comparative anatomy of the seal larynx]. | | 1963 | 13992179 |
| the 'hood' of the hooded seal, cystophora cristata. | | 1884 | 17751166 |
| a study of metal concentrations and metallothionein binding capacity in liver, kidney and brain tissues of three arctic seal species. | arctic seals are known to accumulate relatively high concentrations of potential toxic heavy metals in their vital organs, such as livers and kidneys, as well as in their central nervous system. we therefore decided to determine whether mercury, copper, cadmium and zinc levels in liver, kidney and brain tissues of three arctic seal species were associated with the intracellular metal-binding protein metallothionein (mt) as a sign of toxic exposure. samples from four ringed (phoca hispida), five ... | 2009 | 19773017 |
| hooded seal (cystophora cristata) pups ingest snow and seawater during their post-weaning fast. | the purpose of this study was to evaluate the importance of exogenous water intake (snow/seawater) in hooded seal (cystophora cristata) pups during their post-weaning fast. in this study, five hooded seal pups had ad lib access to snow and seawater for the first 12 and last 21 days of their post-weaning fast, respectively. total body water and water flux were determined during both exposure periods by use of the tritiated water method. blood samples were collected to monitor changes in hematocri ... | 2017 | 27830333 |
| size and distribution of oxygen stores in harp and hooded seals from birth to maturity. | pinnipeds rely primarily on oxygen stores in blood and muscles to support aerobic diving; therefore rapid development of body oxygen stores (tbo(2)) is crucial for pups to transition from nursing to independent foraging. here, we investigate tbo(2) development in 45 harp (pagophilus groenlandicus) and 46 hooded (cystophora cristata) seals ranging in age from neonates to adult females. we found that hooded seal adults have the largest tbo(2) stores yet reported (89.5 ml kg(-1)), while harp seal a ... | 2007 | 17576570 |
| panmictic population structure in the hooded seal (cystophora cristata). | two putative populations of hooded seals (cystophora cristata) occur in the north atlantic. the greenland sea population pup and breed on the pack ice near jan mayen ('west ice') while the northwest atlantic population is thought to pup in the davis strait, in the gulf of st. lawrence (the 'gulf'), and off southern labrador or northeast newfoundland (the 'front'). we used microsatellite profiling of 300 individuals at 13 loci and mitochondrial dna sequencing of the control region of 123 individu ... | 2007 | 17402979 |
| inhibition of shivering in hypothermic seals during diving. | the mammalian response to hypothermia is increased metabolic heat production, usually by way of muscular activity, such as shivering. seals, however, have been reported to respond to diving with hypothermia, which in other mammals under other circumstances would have elicited vigorous shivering. in the diving situation, shivering could be counterproductive, because it obviously would increase oxygen consumption and therefore reduce diving capacity. we have measured the electromyographic (emg) ac ... | 2005 | 15761184 |
| melatonin reduces noradrenaline-induced vasoconstriction in the uterine artery of pregnant hooded seals (cystophora cristata). | in pregnant seals the dive-associated constriction of the uterine artery is inhibited for unknown reasons. the seal fetus has an extremely large and active pineal gland, not found in any other mammals. we have investigated if the pineal hormone melatonin affects fetal blood supply during diving. using isolated ring segments of the uterine artery from pregnant hooded seals (cystophora cristata), we measured the change in isometric tension caused by noradrenaline (na) with and without physiologica ... | 2004 | 14634822 |
| quantitative differences in the pineal ultrastructure of perinatal and adult harp (phoca groenlandica) and hooded seals (cystophora cristata). | seals are unique among mammals in that newborns have a large pineal gland and extremely high plasma levels of melatonin at birth. melatonin levels are also high in the seal fetus but decline rapidly during the first few days of life. the aim of the present study was to provide quantitative information about the ultrastructure of the seal pineal gland using fetal, newborn, and adult hooded seals (cystophora cristata), and newborn and adult harp seals (phoca groenlandica). the relative and absolut ... | 2003 | 12932203 |
| health status of harp seals (phoca groenlandica) and hooded seals (cystophora cristata) on sable island, nova scotia, canada, concurrent with their expanding range. | beach surveys for harp (phoca groenlaandica) and hooded (cystophora cristata) seals documented a dramatic increase in their numbers on sable island in mid 1990s. in the 1980s, no more than five animals of both species were observed on this island each year, however, during late 1994 to 1998, 1,191 harp and 870 hooded seals, mostly young animals, were recorded. although some of these seals had been killed by sharks, most (roughly 75%) were found alive or as intact carcasses on the beach, and some ... | 2003 | 12685065 |
| melatonin is rhythmic in newborn seals exposed to continuous light. | we have investigated the effect of continuous light and darkness on plasma levels of melatonin in relation to the extremely large and active pineal gland typically found in newborn seals. plasma levels of melatonin in captive newborn harp (phoca groenlandica) and hooded seals (cystophora cristata) were generally extremely high, with peak concentrations ranging from 0.8 ng/ml to 62.3 ng/ml. moreover, plasma melatonin showed a similar, pronounced rhythmicity, both outdoors under natural light cond ... | 2003 | 12592441 |
| new data characterizing the metabolic status of hooded (cystophora cristata erxleben, 1777) and harp (pagophilus groenlandica erxleben, 1777) seals in the early postnatal period of development. | | 2016 | 22134817 |
| carcinoid in the lung of a hooded seal (cystophora cristata). | | 2004 | 12521252 |
| how can the hooded seal dive to a depth of 1000 m without rupturing its tympanic membrane? a morphological and functional study. | recent studies using a satellite-linked dive recorder have shown that the hooded seal (cystophora cristata), a common arctic pinniped, can dive to a depth of > 1000 m and stay submerged for close to 1 h. at these depths the water pressure reaches 100 atm, entailing obvious risk of serious damage to the hearing apparatus, mainly the tympanic membrane (tm) and middle ear (me). we dissected and photodocumented the temporal bones of five newborn and three adult hooded seals in order to study the tem ... | 2001 | 11678167 |
| experimental evidence of seawater drinking in juvenile hooded (cystophora cristata) and harp seals (phoca groenlandica). | this study was undertaken to measure whether young harp seals (phoca groenlandica) and hooded seals (cystophora cristata) drink seawater and, if so, to investigate how the excess salt load is handled. blood and urine samples were collected from hooded seal pups (n = 3) and harp seal pups (n = 3) after 2 weeks of freshwater exposure, at intervals during 3 weeks of seawater exposure and, finally, after 2 weeks of re-exposure to fresh water. total water turnover, as measured by injection of tritiat ... | 2000 | 11083522 |
| the eye of the hooded seal, cystophora cristata, in air and water. | multiple refractive state measurements were made on a male and female hooded seal (cystophora cristata) when the eyes were exposed to air and to water. the measures, made by conventional retinoscopy and by photorefraction, show that the seals are moderately hyperopic (2-3 diopters) in water and moderately myopic (2-4 diopters) in air. no significant astigmatism was noted in either medium. the absence of refractive state variation over time suggests that an accommodative mechanism is insignifican ... | 2006 | 2810150 |