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Callorhinus

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Terry R. Spraker – 1st expert on this subject based on the ideXlab platform

  • digeneans of northern fur seals Callorhinus ursinus pinnipedia otariidae from five subpopulations on st paul island alaska
    Parasitology Research, 2018
    Co-Authors: T A Kuzmina, Terry R. Spraker, E T Lyons, Vasyl V Tkach, Olena Kudlai

    Abstract:

    A parasitological survey of 651 northern fur seals Callorhinus ursinus L. from five subpopulations was conducted on St. Paul Island, Alaska, during July–August 2012–2014. Digenean trematodes were found in 210 of 651 fur seals with a total prevalence of 32.3%. Intensity of infection varied from 1 to 1540 parasites with mean intensity 18.4 ± 111.1 SD and median intensity of 2 specimens per host. Significant differences in prevalence and intensity of infection in northern fur seals between separate rookeries was not observed (Mann–Whitney test; p > 0.05). Four species of digeneans belonging to the families Heterophyidae (Apophallus zalophi Price, 1932, Phocitrema fusiforme Goto and Ozaki, 1930, and Galactosomum ubelakeri (Dailey, 1969)) and Troglotrematidae (Nanophyetus salmincola (Chapin, 1926)) were found. Nanophyetus salmincola is reported from C. ursinus for the first time. We obtained partial 28S rDNA sequences for all digenean species and conducted molecular phylogenetic analysis to demonstrate their phylogenetic relationships.

  • the cestode community in northern fur seals Callorhinus ursinus on st paul island alaska
    International journal for parasitology. Parasites and wildlife, 2015
    Co-Authors: T A Kuzmina, Terry R. Spraker, E T Lyons, Jesus S Hernandezorts, Vadym V Kornyushyn, Roman Kuchta

    Abstract:

    The diversity and ecology of cestodes from the northern fur seals, Callorhinus ursinus (NFS), were examined using newly collected material from 756 humanely harvested subadult males between 2011 and 2014. NFSs were collected from five different haul-outs on St. Paul Island, Alaska. A total of 14,660 tapeworms were collected with a prevalence of 98.5% and intensity up to 107 cestodes per host (mean intensity 19.7 ± 16.5 SD). Three species of tapeworms were found: Adenocephalus pacificus (Diphyllobothriidea) was the most prevalent (prevalence 97.4%), followed by Diplogonoporus tetrapterus (49.7%), and 5 immature specimens of Anophryocephalus cf. ochotensis (Tetrabothriidea) (0.5%). Most of the cestodes found in the NFS were immature (69.7%). However, only 0.9% of cestodes were in larval (plerocercoid) stages. The species composition, prevalence and intensity of cestodes from these NFSs were not statistically different between the five separate haul-outs. Significant increases in the intensity of NFS infections were observed during the study period.

  • bilaterally symmetrical lesions of the caudate nucleus in a northern fur seal pup Callorhinus ursinus
    Veterinary Record Case Reports, 2015
    Co-Authors: Vanessa Fravel, William Van Bonn, Sophie Dennison, Terry R. Spraker

    Abstract:

    A northern fur seal ( Callorhinus ursinus ) pup was stranded and brought to The Marine Mammal Center (TMMC) in Sausalito, California, USA, for rehabilitation. Upon admission, the animal was lethargic, underweight and ataxic. Clinical diagnostics, including complete blood cell count (CBC), serum chemistry, protozoal antibody titres, radiographs and cisterna magna ultrasonography, were completed and considered within normal limits. MRI of the brain revealed bilaterally symmetrical focal lesions of the rostrolateral caudate nucleus. Treatment for thiamine deficiency and immune-mediated disease was initiated, but the pup did not improve. The pup was euthanased and postmortem examination revealed no gross lesions. Histopathology revealed bilateral regions of oedema, and areas of early malacia, within the caudate nucleus. Although the aetiology is not identified, the distribution of the lesions suggests a toxic insult or could be related to a developmental neurodegenerative disease. This case also gives an insight into the potential role of the caudate nucleus in fur seals.

E T Lyons – 2nd expert on this subject based on the ideXlab platform

  • digeneans of northern fur seals Callorhinus ursinus pinnipedia otariidae from five subpopulations on st paul island alaska
    Parasitology Research, 2018
    Co-Authors: T A Kuzmina, Terry R. Spraker, E T Lyons, Vasyl V Tkach, Olena Kudlai

    Abstract:

    A parasitological survey of 651 northern fur seals Callorhinus ursinus L. from five subpopulations was conducted on St. Paul Island, Alaska, during July–August 2012–2014. Digenean trematodes were found in 210 of 651 fur seals with a total prevalence of 32.3%. Intensity of infection varied from 1 to 1540 parasites with mean intensity 18.4 ± 111.1 SD and median intensity of 2 specimens per host. Significant differences in prevalence and intensity of infection in northern fur seals between separate rookeries was not observed (Mann–Whitney test; p > 0.05). Four species of digeneans belonging to the families Heterophyidae (Apophallus zalophi Price, 1932, Phocitrema fusiforme Goto and Ozaki, 1930, and Galactosomum ubelakeri (Dailey, 1969)) and Troglotrematidae (Nanophyetus salmincola (Chapin, 1926)) were found. Nanophyetus salmincola is reported from C. ursinus for the first time. We obtained partial 28S rDNA sequences for all digenean species and conducted molecular phylogenetic analysis to demonstrate their phylogenetic relationships.

  • the cestode community in northern fur seals Callorhinus ursinus on st paul island alaska
    International journal for parasitology. Parasites and wildlife, 2015
    Co-Authors: T A Kuzmina, Terry R. Spraker, E T Lyons, Jesus S Hernandezorts, Vadym V Kornyushyn, Roman Kuchta

    Abstract:

    The diversity and ecology of cestodes from the northern fur seals, Callorhinus ursinus (NFS), were examined using newly collected material from 756 humanely harvested subadult males between 2011 and 2014. NFSs were collected from five different haul-outs on St. Paul Island, Alaska. A total of 14,660 tapeworms were collected with a prevalence of 98.5% and intensity up to 107 cestodes per host (mean intensity 19.7 ± 16.5 SD). Three species of tapeworms were found: Adenocephalus pacificus (Diphyllobothriidea) was the most prevalent (prevalence 97.4%), followed by Diplogonoporus tetrapterus (49.7%), and 5 immature specimens of Anophryocephalus cf. ochotensis (Tetrabothriidea) (0.5%). Most of the cestodes found in the NFS were immature (69.7%). However, only 0.9% of cestodes were in larval (plerocercoid) stages. The species composition, prevalence and intensity of cestodes from these NFSs were not statistically different between the five separate haul-outs. Significant increases in the intensity of NFS infections were observed during the study period.

  • update on the prevalence of the hookworm uncinaria lucasi in northern fur seals Callorhinus ursinus on st paul island alaska 2011
    Parasitology Research, 2012
    Co-Authors: E T Lyons, T A Kuzmina, S C Tolliver, Terry R. Spraker

    Abstract:

    Prevalence of hookworms (Uncinaria lucasi Stiles, 1901) was determined in the northern fur seal (Callorhinus ursinus Linnaeus, 1758) on St. Paul Island (SPI), Alaska in July and August, 2011. Three of 61 (4.9%) dead pups harbored 1 to 13 adult hookworms each in their intestines. Parasitic larvae (L3) of hookworms were recovered from the blubber of 4 of 133 (3%) of subadult males (SAMs) examined. One parasitic L3 was detected from each infected SAM. Adult U. lucasi (n = 3) were found in the intestine of 1 of 105 SAMs examined (0.95%). This is the first documented finding of adult U. lucasi in SAMs of the northern fur seals. Continued low prevalence of hookworms the last several years parallels the tremendous decline in the number of fur seals on SPI over a similar time period.

Stephen J Insley – 3rd expert on this subject based on the ideXlab platform

  • Long-term vocal recognition in the northern fur seal
    Nature, 2000
    Co-Authors: Stephen J Insley

    Abstract:

    The ability to recognize and remember individual identities for long periods of time has important implications for the evolution of animal social behaviour, particularly complex interactions such as cooperation or mate choice. Despite this importance, there is only a single example of long-term individual recognition in nature, the 8-month retention of neighbour’s song among male hooded warblers, Wilsonia citrina, and there is none for a non-human mammal. Associations between individuals spanning years, which are especially prevalent in carnivores, primates and seabirds, and evidence of mate fidelity provide indirect support for the ability of long-term recognition. In many of these instances, however, individuals do not separate for extended periods, and thus long-term recognition, although often assumed, may be both unnecessary and nonexistent. Furthermore, site fidelity rather than individual recognition may explain many instances of mate fidelity. Here I show that mother-offspring pairs of a migratory otariid pinniped–the northern fur seal (Callorhinus ursinus)–not only have the ability to recognize each other’s vocalizations during the course of a breeding season, but are also able to retain these memories for at least 4 years.

  • Long-term vocal recognition in the northern fur seal. (Callorhinus ursinus)
    NATURE (LONDON) 406(6794):404-405. 2000., 2000
    Co-Authors: Stephen J Insley

    Abstract:

    The ability to recognize and remember individual identities for long periods of time has important implications for the evolution of animal social behaviour, particularly complex interactions such as cooperation or mate choice. Despite this importance, there is only a single example of long-term individual recognition in nature, the 8-month retention of neighbour’s song among male hooded warblers, Wilsonia citrina, and there is none for a non-human mammal. Associations between individuals spanning years, which are especially prevalent in carnivores, primates and seabirds, and evidence of mate fidelity provide indirect support for the ability of long-term recognition. In many of these instances, however, individuals do not separate for extended periods, and thus long-term recognition, although often assumed, may be both unnecessary and nonexistent. Furthermore, site fidelity rather than individual recognition may explain many instances of mate fidelity. Here I show that mother–offspring pairs of a migratory otariid pinniped—the northern fur seal (Callorhinus ursinus)—not only have the ability to recognize each other’s vocalizations during the course of a breeding season, but are also able to retain these memories for at least 4 years.