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John J Burns - One of the best experts on this subject based on the ideXlab platform.
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comparative morphology of the skull of the Ribbon Seal histriophoca fasciata with remarks on systematics of phocidae
Journal of Zoology, 2010Co-Authors: John J BurnsAbstract:Study of skulls from 145 Ribbon Seals, mainly from the Bering Sea, disclosed much greater variation in form than was indicated by earlier descriptions. The characters of greatest diagnostic value in the Ribbon Seal are the short rostrum, broad cranium with reduced temporal fossae. short, wide palate with small, widely spaced teeth, and the elongate, thickwalled bullae with massive, widely exposed petrosals. Comparison of these skulls with examples from each of the other recognized genera of Phocidae revealed several deficiencies in the referred cranial characteristics of taxa at all ranks below the family. Provisional support for J. E. King's recently proposed division of the Phocidae into two subfamilies, Phocinae and Monachinae, is reported; the distinctions formerly employed for diagnosis of a third subfamily, Cystophorinae, can be ascribed to convergent evolution. Craniologically, the subfamily Phocinae is divisible into three tribes: Erignathini, Cystophorini, and Phocini. The first two are monotypic; the third is polytypic. The subtribes Phocina and Histriophocina are untenable; while Histriophoca's nearest structural relative is Pagophilus, the latter shows equal or closer relationship with Phocu. Within the tribe Phocini, only the Grey Seal, Hlichoerus grypus, shows sufficient cranial differentiation for recognition as a monotypic genus. The other four major taxa within that tribe show a complex system of intergrading characters that disallows generic recognition, other than as a polytypic group. Therefore, the Ribbon, Harp, Harbor, and Ringed Seals are re-assigned to subgeneric rank, under the inclusive genus Phoca (sensu luto).
Sue E. Moore - One of the best experts on this subject based on the ideXlab platform.
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Incidental Sighting of a Ribbon Seal (Phoca fasciata) in the Western Beaufort Sea
2014Co-Authors: Sue E. Moore, Edith I. BarrowcloughAbstract:On 29 August 1983, an adult Ribbon Seal (Phocufusciutu) was a contributing factor. The observed Ribbon Seal may have seen by one of us (EIB) resting on ice in the western Beaufort drifted north and east with the ice from the Chukchi Sea during Sea (71”41’N, 152’41’”; Fig. 11, during the course of an the summer. To our knowledge, this report constitutes the.aerial survey. The Seal did not move from the ice when over-flown at 200 m, and was positively identified by its distinctive pelage. Ribbon Seals are commonly found along the ice front in the Bering Sea in winter and early spring, then disperse in late spring as the sea ice breaks up and presumably become solitary and pelagic with poorly known distribution in the summe
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comparing marine mammal acoustic habitats in atlantic and pacific sectors of the high arctic year long records from fram strait and the chukchi plateau
Polar Biology, 2012Co-Authors: Sue E. Moore, Kathleen M Stafford, Humfrey Melling, Catherine L Berchok, Oystein Wiig, Kit M Kovacs, Christian Lydersen, Jackie RichtermengeAbstract:During the International Polar Year (IPY), acoustic recorders were deployed on oceanographic moorings in Fram Strait and on the Chukchi Plateau, representing the first coordinated year-round sampling of underwater acoustic habitats at two sites in the High Arctic. Examination of species-specific marine mammal calls recorded from autumn 2008–2009 revealed distinctly different acoustic habitats at each site. Overall, the Fram Strait site was acoustically complex compared with the Chukchi Plateau site. In Fram Strait, calls from bowhead whales (Balaena mysticetus) and a variety of toothed whales (odontocetes) were recorded year-round, as were airgun pulses from seismic surveys. In addition, calls from blue whales (Balaenoptera musculus) and fin whales (B. physalus) were recorded from June to October and August to March, respectively. Conversely, at the Chukchi Plateau site, beluga (Delphinapterus leucas) and bowhead whale calls were recorded primarily from May to August, with airgun signals detected only in September–October. Ribbon Seal (Phoca fasciata) calls were detected in October–November, with no marine mammals calls at all recorded from December to February. Of note, ice-adapted bearded Seals (Erignathus barbatus) were recorded at both sites, primarily in spring and summer, corresponding with the mating season for that species. Differences in acoustic habitats between the two sites were related to contrasts in sea ice cover, temperature, patterns of ocean circulation and contributions from anthropogenic noise sources. These data provide a provisional baseline for the comparison of underwater acoustic habitats between Pacific and Atlantic sectors of the High Arctic.
Edith I. Barrowclough - One of the best experts on this subject based on the ideXlab platform.
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Incidental Sighting of a Ribbon Seal (Phoca fasciata) in the Western Beaufort Sea
2014Co-Authors: Sue E. Moore, Edith I. BarrowcloughAbstract:On 29 August 1983, an adult Ribbon Seal (Phocufusciutu) was a contributing factor. The observed Ribbon Seal may have seen by one of us (EIB) resting on ice in the western Beaufort drifted north and east with the ice from the Chukchi Sea during Sea (71”41’N, 152’41’”; Fig. 11, during the course of an the summer. To our knowledge, this report constitutes the.aerial survey. The Seal did not move from the ice when over-flown at 200 m, and was positively identified by its distinctive pelage. Ribbon Seals are commonly found along the ice front in the Bering Sea in winter and early spring, then disperse in late spring as the sea ice breaks up and presumably become solitary and pelagic with poorly known distribution in the summe
Shoichi Fujita - One of the best experts on this subject based on the ideXlab platform.
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identification of novel cytochrome p450 1a genes from five marine mammal species
Aquatic Toxicology, 2000Co-Authors: Ikuko Teramitsu, Issei Chiba, Fumiaki Akahori, Hisato Iwata, Akio Kazusaka, Yukio Yamamoto, Shinsuke Tanabe, Yoshihiro Fujise, Shoichi FujitaAbstract:Marine mammals, being endangered by the chronic exposure of hydrophobic environmental contaminants as an assorting result of global pollution, are especially focused as indicators for organochlorine pollution. The use of contaminant-induced xenobiotic metabolizers, particularly P450 (CYP) 1A, in marine mammals can be effective as potential biomarkers of the contaminant exposure and/or toxic effects. In this study, we identified the first marine mammalian CYPs. Six novel CYP1A cDNA fragments were cloned from the livers of marine mammal species, minke whale (Balaenoptera acutorostrata), dall's porpoise (Phocoenoides dalli), steller sea lion (Eumetopias jubatus), largha Seal (Phoca largha), and Ribbon Seal (Phoca fasciata) by the method of reverse transcription/polymerase chain reaction (RT/PCR); two distinct fragments were from steller sea lion and one fragment each was obtained from the other species. Five of the fragments, one from each species, were classified in the subfamily of CYP1A1, and the other fragment cloned from steller sea lion was designated CYP1A2. Degenerate PCR primers were used to amplify the fragments from liver cDNAs. The deduced amino acid sequences of these fragment CYP1As showed identities ranging from 50.0 to 94.3% with other known vertebrate CYPs in the subfamily of CYP1A, including those from fish, chicken, and terrestrial mammals. The isolated fragments were used to construct a molecular phylogeny, along with other vertebrate CYP1A cDNAs cut down in size to the corresponding region of 265 bp in which those newly determined fragments were cloned. This phylogenetic analysis by the maximum parsimony method using the PHYLIP program suggests two distinct evolutional pathways for aquatic mammalian CYP1As, compatible to a conservative taxonomy. Pinniped genes are clustered together with dog gene, forming a carnivore group, and cetaceans form another branch. Identification of CYP1A genes in marine mammals will be an introductory step to provide new insights into the metabolic or toxicological functions of CYP1As in these animals.
Ikuko Teramitsu - One of the best experts on this subject based on the ideXlab platform.
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identification of novel cytochrome p450 1a genes from five marine mammal species
Aquatic Toxicology, 2000Co-Authors: Ikuko Teramitsu, Issei Chiba, Fumiaki Akahori, Hisato Iwata, Akio Kazusaka, Yukio Yamamoto, Shinsuke Tanabe, Yoshihiro Fujise, Shoichi FujitaAbstract:Marine mammals, being endangered by the chronic exposure of hydrophobic environmental contaminants as an assorting result of global pollution, are especially focused as indicators for organochlorine pollution. The use of contaminant-induced xenobiotic metabolizers, particularly P450 (CYP) 1A, in marine mammals can be effective as potential biomarkers of the contaminant exposure and/or toxic effects. In this study, we identified the first marine mammalian CYPs. Six novel CYP1A cDNA fragments were cloned from the livers of marine mammal species, minke whale (Balaenoptera acutorostrata), dall's porpoise (Phocoenoides dalli), steller sea lion (Eumetopias jubatus), largha Seal (Phoca largha), and Ribbon Seal (Phoca fasciata) by the method of reverse transcription/polymerase chain reaction (RT/PCR); two distinct fragments were from steller sea lion and one fragment each was obtained from the other species. Five of the fragments, one from each species, were classified in the subfamily of CYP1A1, and the other fragment cloned from steller sea lion was designated CYP1A2. Degenerate PCR primers were used to amplify the fragments from liver cDNAs. The deduced amino acid sequences of these fragment CYP1As showed identities ranging from 50.0 to 94.3% with other known vertebrate CYPs in the subfamily of CYP1A, including those from fish, chicken, and terrestrial mammals. The isolated fragments were used to construct a molecular phylogeny, along with other vertebrate CYP1A cDNAs cut down in size to the corresponding region of 265 bp in which those newly determined fragments were cloned. This phylogenetic analysis by the maximum parsimony method using the PHYLIP program suggests two distinct evolutional pathways for aquatic mammalian CYP1As, compatible to a conservative taxonomy. Pinniped genes are clustered together with dog gene, forming a carnivore group, and cetaceans form another branch. Identification of CYP1A genes in marine mammals will be an introductory step to provide new insights into the metabolic or toxicological functions of CYP1As in these animals.