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E T Lyons - One of the best experts on this subject based on the ideXlab platform.
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epidemiology of hookworm Uncinaria spp infection in new zealand hooker s sea lion phocarctos hookeri pups on enderby island auckland islands new zealand during the breeding seasons from 1999 2000 to 2004 2005
Parasitology Research, 2007Co-Authors: A Castinel, Pádraig J. Duignan, E T Lyons, W E Pomroy, N J Gibbs, N Lopezvillalobos, B L Chilvers, I S WilkinsonAbstract:This is the first investigation of the epidemiology of hookworm (Uncinaria spp.) infection in New Zealand sea lions (NZSLs; Phocarctos hookeri) on Enderby Island, Auckland Islands. The examination of faeces for hookworm eggs in various age categories of sea lions revealed that only pups up to at least 3 months of age harboured adult hookworms in their intestines. Gross necropsy of more than 400 pups from 1999/2000 to 2004/2005 showed that the prevalence of hookworm infection varied significantly between years and was higher from mid-January to the end of February when the majority of pups were between 3 and 9 weeks old. The average burden of adult parasites per pup was not influenced by the host’s sex and body condition or by year. This study also provided evidence for transmission occurring by the transmammary route in NZSLs.
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First report and characterization of adult Uncinaria spp. in New Zealand Sea Lion (Phocarctos hookeri) pups from the Auckland Islands, New Zealand
Parasitology Research, 2006Co-Authors: A Castinel, E T Lyons, W E Pomroy, I S Wilkinson, P. J. Duignan, S. A. Nadler, M. D. Dailey, B L ChilversAbstract:Two species of hookworms ( Uncinaria lucasi and Uncinaria hamiltoni ) have been formally described from pinnipeds, but dissimilar types are noted from these hosts. This report is the first description of hookworms ( Uncinaria spp.) from the New Zealand sea lion, Phocarctos hookeri. The nematodes were collected from dead pups on Enderby Island (Auckland Islands, 50°30', 166°17') during January and February, 2004. Standard measurements of male and female hookworms were obtained, providing a general morphometric characterization of the hookworm species in P. hookeri. Considerable variations in the body length of adult hookworms were noted within the same host. The arrangement of some of the bursal rays differs from that described for U. lucasi and U. hamiltoni .
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Photomicrographic images of some features of Uncinaria spp (Nematoda: Ancylostomatidae) from otariid pinnipeds
Parasitology Research, 2005Co-Authors: E T Lyons, R. L. DelongAbstract:Photomicrographs of several morphologic features of hookworms ( Uncinaria spp) from northern fur seal ( Callorhinus ursinus ) and California sea lion ( Zalophus californianus ) pups are presented. The main purpose is to show and describe some physical characteristics of hookworms from the two hosts; it is not to decide from these attributes whether the Uncinaria spp are the same species. The number of species of Uncinaria in pinnipeds is uncertain and specimens need to be examined from the various infected seals and sea lions before the taxonomy of these parasites can be clarified. Information in the present paper should aid in this determination.
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historic importance of some aspects of research by o wilford olsen on hookworms Uncinaria lucasi in northern fur seals callorhinus ursinus and steller sea lions eumatopias jubatus in 1951 on st paul island alaska
Parasitology Research, 2005Co-Authors: E T LyonsAbstract:The purpose of this paper is to disseminate, more widely, certain historically important aspects of research by O. Wilford Olsen on hookworms (Uncinaria lucasi) in northern fur seals (Callorhinus ursinus) and Steller sea lions (Eumatopias jubatus) in 1951 on St. Paul Island, Alaska. Highly meaningful facets of the research were recorded only in a report with limited availability by Olsen in 1952. Portions of his research presented here include measurements of hookworm free-living infective third-stage larvae (L3) and adults, photographs of bursae, and the conclusion that the species of hookworms (U. lucasi) is probably the same in both pinniped hosts. This information is especially important because very little has been published on taxonomy of hookworms in E. jubatus.
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historic importance of some aspects of research by o wilford olsen on hookworms Uncinaria lucasi in northern fur seals callorhinus ursinus and steller sea lions eumatopias jubatus in 1951 on st paul island alaska
Parasitology Research, 2005Co-Authors: E T LyonsAbstract:The purpose of this paper is to disseminate, more widely, certain historically important aspects of research by O. Wilford Olsen on hookworms (Uncinaria lucasi) in northern fur seals (Callorhinus ursinus) and Steller sea lions (Eumatopias jubatus) in 1951 on St. Paul Island, Alaska. Highly meaningful facets of the research were recorded only in a report with limited availability by Olsen in 1952. Portions of his research presented here include measurements of hookworm free-living infective third-stage larvae (L3) and adults, photographs of bursae, and the conclusion that the species of hookworms (U. lucasi) is probably the same in both pinniped hosts. This information is especially important because very little has been published on taxonomy of hookworms in E. jubatus.
Terry R Spraker - One of the best experts on this subject based on the ideXlab platform.
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a study of Uncinariasis in northern fur seal pups callorhinus ursinus on the rookeries of bering island 2011 2012
Russian Journal of Marine Biology, 2019Co-Authors: Sergey V Fomin, L I Konovalova, O A Belonovich, Terry R SprakerAbstract:Carcasses of northern fur seal pups, Callorhinus ursinus, collected from the rookeries of Bering Island (n = 133), were examined for hookworms Uncinaria spp. The parasite was found in 90% of the pups from the Severo-Zapadnoe rookery and in 45% of the pups from the Severnoe rookery. This difference in prevalence of nematode infection between the rookeries is associated with the type of substrate, as well as with the pattern of distribution of the seal reproductive groups on each of the rookeries.
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parasitological examination of northern elephant seal mirounga angustirostris pups for presence of hookworms Uncinaria spp on san miguel island california
Helminthologia, 2016Co-Authors: Tatiana A Kuzmina, Terry R Spraker, Robert L DelongAbstract:Necropsy and extensive parasitological examination of dead northern elephant seal (NES) pups was done on San Miguel Island, California, in February, 2015. The main interest in the current study was to determine if hookworms were present in NESs on San Miguel Island where two hookworm species of the genus Uncinaria are known to be present - Uncinaria lyonsi in California sea lions and Uncinaria lucasi in northern fur seals. Hookworms were not detected in any of the NESs examined: stomachs or intestines of 16 pups, blubber of 13 pups and blubber of one bull. The results obtained in the present study of NESs on San Miguel Island plus similar finding on Ano Nuevo State Reserve and The Marine Mammal Center provide strong indication that NES are not appropriate hosts for Uncinaria spp. Hookworm free-living third stage larvae, developed from eggs of California sea lions and northern fur seals, were recovered from sand. It seems that at this time, further search for hookworms in NESs would be nonproductive.
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Parasitological examination for presence of hookworms ( Uncinaria spp.) in northern elephant seals ( Mirounga angustirostris ) at Año Nuevo State Reserve, California (2012)
Parasitology Research, 2012Co-Authors: Eugene T. Lyons, Terry R Spraker, Tatiana A Kuzmina, N. Jaggi, Daniel P. Costa, Daniel E. Crocker, Sharon C. Tolliver, Michael S. TiftAbstract:Northern elephant seals (Mirounga angustirostris Gill, 1866), inhabiting rookeries on the mainland of Ano Nuevo State Reserve in central California, were investigated in 2012 for presence of hookworms (Uncinaria spp.). Material collected and examined for hookworms included: blubber (n = 15), stomach and intestines (n = 21) from dead pups; feces from the rectum of weaned pups (n = 23); sand containing apparent feces in areas of weaned pups (n = 28) and sand without apparent feces in areas of weaned pups (n = 54); milk from females (n =23) at 5 days and about 23 to 26 days postpartum; and placenta from one female. Evidence of hookworm presence was not detected in any of the samples examined. Possible reasons why hookworms were not found in northern elephant seals on the mainland of Ano Nuevo State Reserve are discussed.
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update on the prevalence of the hookworm Uncinaria lucasi in northern fur seals callorhinus ursinus on st paul island alaska 2011
Parasitology Research, 2012Co-Authors: Tatiana A Kuzmina, Terry R SprakerAbstract: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.
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Review of research on hookworms (Uncinaria lucasi Stiles, 1901) in northern fur seals (Callorhinus ursinus Linnaeus, 1758)
Parasitology Research, 2011Co-Authors: Terry R Spraker, Mariana Ionita, Sharon R. Melin, Robert L. Long, Steven A NadlerAbstract:The objective of this article is to review knowledge on the hookworm Uncinaria lucasi Stiles, 1901 in northern fur seals, Callorhinus ursinus Linnaeus, 1758. Emphasis is placed on research on this host–parasite system in the Pribilof Islands, AK, USA where the bulk of the studies has been performed.
Steven A Nadler - One of the best experts on this subject based on the ideXlab platform.
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host population expansion and the genetic architecture of the pinniped hookworm Uncinaria lucasi
Journal of Parasitology, 2020Co-Authors: Keely Davies, Chris Pagan, Steven A NadlerAbstract:The long-term fidelity of pinniped hosts to their natal rookery site suggests the genetic architecture of their Uncinaria spp. hookworms should be strongly structured by host breeding biology. However, historical events affecting host populations may also shape parasite genetic structure. Sequences of the mitochondrial cytochrome c oxidase 1 (COI) gene of 86 Uncinaria lucasi individuals were obtained to assess genetic variation and structure of nematodes from 2 host species (68 hookworms from northern fur seals; 18 hookworms from Steller sea lions) and rookeries from 3 widely separated geographic regions: the western Bering Sea and Sea of Okhotsk, eastern Bering Sea, and the eastern Pacific Ocean. High COI haplotype (h = 0.96-0.98) and nucleotide (π = 0.014) diversity was found. The haplotype network showed a star-shaped pattern with a large number of haplotypes separated by few substitutions. The network did not show separation of U. lucasi by geographic region or host species. Fst values between U. lucasi individuals representing geographic regions showed no differentiation, consistent with the absence of genetic structure. At face value, this lack of genetic structure in U. lucasi suggests high gene flow but could also be explained by recent (post-glacial) population expansions of northern fur seals and their hookworms.
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morphological variability and molecular identification of Uncinaria spp nematoda ancylostomatidae from grizzly and black bears new species or phenotypic plasticity
Journal of Parasitology, 2015Co-Authors: Stefano Catalano, Manigandan Lejeune, Paolo Tizzani, Pádraig J. Duignan, Bradley J Van Paridon, Christopher A Pagan, James D Wasmuth, Steven A NadlerAbstract:Abstract: The hookworms Uncinaria rauschi Olsen, 1968 and Uncinaria yukonensis (Wolfgang, 1956) were formally described from grizzly (Ursus arctos horribilis) and black bears (Ursus americanus) of North America. We analyzed the intestinal tracts of 4 grizzly and 9 black bears from Alberta and British Columbia, Canada and isolated Uncinaria specimens with anatomical traits never previously documented. We applied morphological and molecular techniques to investigate the taxonomy and phylogeny of these Uncinaria parasites. The morphological analysis supported polymorphism at the vulvar region for females of both U. rauschi and U. yukonensis. The hypothesis of morphological plasticity for U. rauschi and U. yukonensis was confirmed by genetic analysis of the internal transcribed spacers (ITS-1 and ITS-2) of the nuclear ribosomal DNA. Two distinct genotypes were identified, differing at 5 fixed sites for ITS-1 (432 base pairs [bp]) and 7 for ITS-2 (274 bp). Morphometric data for U. rauschi revealed host-relate...
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molecular systematics of pinniped hookworms nematoda Uncinaria species delimitation host associations and host induced morphometric variation
International Journal for Parasitology, 2013Co-Authors: Steven A Nadler, Robert L Delong, Eugene T. Lyons, A Castinel, Christopher Pagan, Derek Hyman, Edwin E Lewis, Kimberlee B Beckmen, Cameron M Bell, Pádraig J. DuignanAbstract:Hookworms of the genus Uncinaria have been widely reported from juvenile pinnipeds, however investigations of their systematics has been limited, with only two species described, Uncinaria lucasi from northern fur seals (Callorhinus ursinus) and Uncinaria hamiltoni from South American sea lions (Otaria flavescens). Hookworms were sampled from these hosts and seven additional species including Steller sea lions (Eumetopias jubatus), California sea lions (Zalophus californianus), South American fur seals (Arctocephalus australis), Australian fur seals (Arctocephalus pusillus), New Zealand sea lions (Phocarctos hookeri), southern elephant seals (Mirounga leonina), and the Mediterranean monk seal (Monachus monachus). One hundred and thirteen individual hookworms, including an outgroup species, were sequenced for four genes representing two loci (nuclear ribosomal DNA and mitochondrial DNA). Phylogenetic analyses of these sequences recovered seven independent evolutionary lineages or species, including the described species and five undescribed species. The molecular evidence shows that U. lucasi parasitises both C. ursinus and E. jubatus, whereas U. hamiltoni parasitises O. flavescens and A. australis. The five undescribed hookworm species were each associated with single host species (Z. californianus, A. pusillus, P. hookeri, M. leonina and M. monachus). For parasites of otarids, patterns of Uncinaria host-sharing and phylogenetic relationships had a strong biogeographic component with separate clades of parasites from northern versus southern hemisphere hosts. Comparison of phylogenies for these hookworms and their hosts suggests that the association of U. lucasi with northern fur seals results from a host-switch from Steller sea lions. Morphometric data for U. lucasi shows marked host-associated size differences for both sexes, with U. lucasi individuals from E. jubatus significantly larger. This result suggests that adult growth of U. lucasi is reduced within the host species representing the more recent host-parasite association. Intraspecific host-induced size differences are inconsistent with the exclusive use of morphometrics to delimit and diagnose species of Uncinaria from pinnipeds.
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Review of research on hookworms (Uncinaria lucasi Stiles, 1901) in northern fur seals (Callorhinus ursinus Linnaeus, 1758)
Parasitology Research, 2011Co-Authors: Terry R Spraker, Mariana Ionita, Sharon R. Melin, Robert L. Long, Steven A NadlerAbstract:The objective of this article is to review knowledge on the hookworm Uncinaria lucasi Stiles, 1901 in northern fur seals, Callorhinus ursinus Linnaeus, 1758. Emphasis is placed on research on this host–parasite system in the Pribilof Islands, AK, USA where the bulk of the studies has been performed.
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investigations of peritoneal and intestinal infections of adult hookworms Uncinaria spp in northern fur seal callorhinus ursinus and california sea lion zalophus californianus pups on san miguel island california 2003
Parasitology Research, 2011Co-Authors: Robert L Delong, Steven A Nadler, Jeffrey L Laake, B L Delong, Cecile PaganAbstract:The peritoneal cavity (PNC) and intestine of northern fur seal (Callorhinus ursinus) pups and California sea lion (Zalophus californianus) pups that died in late July and early August, 2003, on San Miguel Island, California, were examined for hookworms. Prevalence and morphometric studies were done with the hookworms in addition to molecular characterization. Based on this and previous molecular studies, hookworms from fur seals are designated as Uncinaria lucasi and the species from sea lions as Uncinaria species A. Adult hookworms were found in the PNC of 35 of 57 (61.4%) fur seal pups and of 13 of 104 (12.5%) sea lion pups. The number of hookworms located in the PNC ranged from 1 to 33 (median = 3) for the infected fur seal pups and 1 to 16 (median = 2) for the infected sea lion pups. In addition to the PNC, intestines of 43 fur seal and 32 sea lion pups were examined. All of these pups were positive for adult hookworms. The worms were counted from all but one of the sea lion pups. Numbers of these parasites in the intestine varied from 3 to 2,344 (median = 931) for the fur seal pups and 39 to 2,766 (median = 643) for the sea lion pups. Sea lion pups with peritoneal infections had higher intensity infections in the intestines than did pups without peritoneal infections, lending some support for the hypothesis that peritoneal infections result from high-intensity infections of adult worms. There was no difference in intestinal infection intensities between fur seal pups with and without peritoneal infections. Female adult hookworms in the intestines of both host species were significantly larger than males, and sea lion hookworms were larger than those in fur seals. Worms in the intestine also were larger than worms found in the PNC. Gene sequencing and (RFLP) analysis of (PCR) amplified (ITS) ribosomal DNA were used to diagnose the species of 172 hookworms recovered from the PNC and intestine of 18 C. ursinus and seven Z. californianus hosts. These molecular data revealed that U. lucasi (hookworm of C. ursinus) and Uncinaria species A (of Z. californianus) infrequently mature in the intestine of the opposite host species in California rookeries. However, there is no support from molecular data for the hypothesis that cross-infection with “the wrong” Uncinaria species is a contributing factor in these cases of host peritonitis. The major significance of this research is the unusual finding of adult hookworms in the PNC of so many dead pups. No obvious explanation for this occurrence could be determined. Further research, like in the present study, should help understand and monitor the apparent ever changing role of hookworm disease in the health of northern fur seal and California sea lion pups on SMI.
Robert L Delong - One of the best experts on this subject based on the ideXlab platform.
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parasitological examination of northern elephant seal mirounga angustirostris pups for presence of hookworms Uncinaria spp on san miguel island california
Helminthologia, 2016Co-Authors: Tatiana A Kuzmina, Terry R Spraker, Robert L DelongAbstract:Necropsy and extensive parasitological examination of dead northern elephant seal (NES) pups was done on San Miguel Island, California, in February, 2015. The main interest in the current study was to determine if hookworms were present in NESs on San Miguel Island where two hookworm species of the genus Uncinaria are known to be present - Uncinaria lyonsi in California sea lions and Uncinaria lucasi in northern fur seals. Hookworms were not detected in any of the NESs examined: stomachs or intestines of 16 pups, blubber of 13 pups and blubber of one bull. The results obtained in the present study of NESs on San Miguel Island plus similar finding on Ano Nuevo State Reserve and The Marine Mammal Center provide strong indication that NES are not appropriate hosts for Uncinaria spp. Hookworm free-living third stage larvae, developed from eggs of California sea lions and northern fur seals, were recovered from sand. It seems that at this time, further search for hookworms in NESs would be nonproductive.
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molecular systematics of pinniped hookworms nematoda Uncinaria species delimitation host associations and host induced morphometric variation
International Journal for Parasitology, 2013Co-Authors: Steven A Nadler, Robert L Delong, Eugene T. Lyons, A Castinel, Christopher Pagan, Derek Hyman, Edwin E Lewis, Kimberlee B Beckmen, Cameron M Bell, Pádraig J. DuignanAbstract:Hookworms of the genus Uncinaria have been widely reported from juvenile pinnipeds, however investigations of their systematics has been limited, with only two species described, Uncinaria lucasi from northern fur seals (Callorhinus ursinus) and Uncinaria hamiltoni from South American sea lions (Otaria flavescens). Hookworms were sampled from these hosts and seven additional species including Steller sea lions (Eumetopias jubatus), California sea lions (Zalophus californianus), South American fur seals (Arctocephalus australis), Australian fur seals (Arctocephalus pusillus), New Zealand sea lions (Phocarctos hookeri), southern elephant seals (Mirounga leonina), and the Mediterranean monk seal (Monachus monachus). One hundred and thirteen individual hookworms, including an outgroup species, were sequenced for four genes representing two loci (nuclear ribosomal DNA and mitochondrial DNA). Phylogenetic analyses of these sequences recovered seven independent evolutionary lineages or species, including the described species and five undescribed species. The molecular evidence shows that U. lucasi parasitises both C. ursinus and E. jubatus, whereas U. hamiltoni parasitises O. flavescens and A. australis. The five undescribed hookworm species were each associated with single host species (Z. californianus, A. pusillus, P. hookeri, M. leonina and M. monachus). For parasites of otarids, patterns of Uncinaria host-sharing and phylogenetic relationships had a strong biogeographic component with separate clades of parasites from northern versus southern hemisphere hosts. Comparison of phylogenies for these hookworms and their hosts suggests that the association of U. lucasi with northern fur seals results from a host-switch from Steller sea lions. Morphometric data for U. lucasi shows marked host-associated size differences for both sexes, with U. lucasi individuals from E. jubatus significantly larger. This result suggests that adult growth of U. lucasi is reduced within the host species representing the more recent host-parasite association. Intraspecific host-induced size differences are inconsistent with the exclusive use of morphometrics to delimit and diagnose species of Uncinaria from pinnipeds.
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investigations of peritoneal and intestinal infections of adult hookworms Uncinaria spp in northern fur seal callorhinus ursinus and california sea lion zalophus californianus pups on san miguel island california 2003
Parasitology Research, 2011Co-Authors: Robert L Delong, Steven A Nadler, Jeffrey L Laake, B L Delong, Cecile PaganAbstract:The peritoneal cavity (PNC) and intestine of northern fur seal (Callorhinus ursinus) pups and California sea lion (Zalophus californianus) pups that died in late July and early August, 2003, on San Miguel Island, California, were examined for hookworms. Prevalence and morphometric studies were done with the hookworms in addition to molecular characterization. Based on this and previous molecular studies, hookworms from fur seals are designated as Uncinaria lucasi and the species from sea lions as Uncinaria species A. Adult hookworms were found in the PNC of 35 of 57 (61.4%) fur seal pups and of 13 of 104 (12.5%) sea lion pups. The number of hookworms located in the PNC ranged from 1 to 33 (median = 3) for the infected fur seal pups and 1 to 16 (median = 2) for the infected sea lion pups. In addition to the PNC, intestines of 43 fur seal and 32 sea lion pups were examined. All of these pups were positive for adult hookworms. The worms were counted from all but one of the sea lion pups. Numbers of these parasites in the intestine varied from 3 to 2,344 (median = 931) for the fur seal pups and 39 to 2,766 (median = 643) for the sea lion pups. Sea lion pups with peritoneal infections had higher intensity infections in the intestines than did pups without peritoneal infections, lending some support for the hypothesis that peritoneal infections result from high-intensity infections of adult worms. There was no difference in intestinal infection intensities between fur seal pups with and without peritoneal infections. Female adult hookworms in the intestines of both host species were significantly larger than males, and sea lion hookworms were larger than those in fur seals. Worms in the intestine also were larger than worms found in the PNC. Gene sequencing and (RFLP) analysis of (PCR) amplified (ITS) ribosomal DNA were used to diagnose the species of 172 hookworms recovered from the PNC and intestine of 18 C. ursinus and seven Z. californianus hosts. These molecular data revealed that U. lucasi (hookworm of C. ursinus) and Uncinaria species A (of Z. californianus) infrequently mature in the intestine of the opposite host species in California rookeries. However, there is no support from molecular data for the hypothesis that cross-infection with “the wrong” Uncinaria species is a contributing factor in these cases of host peritonitis. The major significance of this research is the unusual finding of adult hookworms in the PNC of so many dead pups. No obvious explanation for this occurrence could be determined. Further research, like in the present study, should help understand and monitor the apparent ever changing role of hookworm disease in the health of northern fur seal and California sea lion pups on SMI.
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penetration of the small intestine of a california sea lion zalophus californianus pup by adult hookworms Uncinaria spp
Parasitology Research, 2004Co-Authors: Terry R Spraker, Robert L Delong, E T Lyons, R R ZinkAbstract:During a study on the mortality of California sea lion (Zalophus californianus) pups born on San Miguel Island, California in 2002, two adult female hookworms (Uncinaria spp) were found penetrating the serosal surface of the intestinal wall and protruding into the peritoneal cavity of one pup. Documentation and a description of this unexpected finding and associated lesions are presented here. Also, adult hookworms were found in the peritoneal fluid of two other dead Z. californianus pups.
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observations in 2001 on hookworms Uncinaria spp in otariid pinnipeds
Parasitology Research, 2003Co-Authors: E T Lyons, Robert L Delong, Terry R Spraker, Sharon R. Melin, S C TolliverAbstract:Uncinaria spp. were recovered from the milk of California sea lions (Zalophus californianus) collected from the: (1) teats of a cow just after parturition (one parasitic third-stage larva, L3), (2) stomach of her nursing pup (two L3), and (3) stomach of a dead pup about 2 days old (one L3, one headless, probably L3, and four L4) on San Miguel Island, California in May 2001. This, in addition to earlier research, indicates transmammary transmission of hookworms in this host. Uncinaria spp. were found in dead northern fur seals (Callorhinus ursinus) in the: (1) intestines of 2 of 75 pups (either one or two adult specimens in each infected pup) and (2) ventral abdominal blubber of 3 of 78 subadult males (one to seven L3 in each infected seal) on St. Paul Island (SPI), Alaska in July and August 2001. These findings verify the low current prevalence of Uncinaria spp. in fur seals on SPI. Rectal fecal samples taken from 50 live Steller sea lion (Eumetopias jubatus) pups, about 1 month old, on Rogue Reef in Curry County, Oregon in July 2001, were all negative for the eggs of Uncinaria spp. The apparent zero infection rate in these pups is possibly because the rocky terrain of this rookery is not suitable for hookworm transmission.
Sharon R. Melin - One of the best experts on this subject based on the ideXlab platform.
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Review of research on hookworms (Uncinaria lucasi Stiles, 1901) in northern fur seals (Callorhinus ursinus Linnaeus, 1758)
Parasitology Research, 2011Co-Authors: Terry R Spraker, Mariana Ionita, Sharon R. Melin, Robert L. Long, Steven A NadlerAbstract:The objective of this article is to review knowledge on the hookworm Uncinaria lucasi Stiles, 1901 in northern fur seals, Callorhinus ursinus Linnaeus, 1758. Emphasis is placed on research on this host–parasite system in the Pribilof Islands, AK, USA where the bulk of the studies has been performed.
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observations in 2001 on hookworms Uncinaria spp in otariid pinnipeds
Parasitology Research, 2003Co-Authors: E T Lyons, Robert L Delong, Terry R Spraker, Sharon R. Melin, S C TolliverAbstract:Uncinaria spp. were recovered from the milk of California sea lions (Zalophus californianus) collected from the: (1) teats of a cow just after parturition (one parasitic third-stage larva, L3), (2) stomach of her nursing pup (two L3), and (3) stomach of a dead pup about 2 days old (one L3, one headless, probably L3, and four L4) on San Miguel Island, California in May 2001. This, in addition to earlier research, indicates transmammary transmission of hookworms in this host. Uncinaria spp. were found in dead northern fur seals (Callorhinus ursinus) in the: (1) intestines of 2 of 75 pups (either one or two adult specimens in each infected pup) and (2) ventral abdominal blubber of 3 of 78 subadult males (one to seven L3 in each infected seal) on St. Paul Island (SPI), Alaska in July and August 2001. These findings verify the low current prevalence of Uncinaria spp. in fur seals on SPI. Rectal fecal samples taken from 50 live Steller sea lion (Eumetopias jubatus) pups, about 1 month old, on Rogue Reef in Curry County, Oregon in July 2001, were all negative for the eggs of Uncinaria spp. The apparent zero infection rate in these pups is possibly because the rocky terrain of this rookery is not suitable for hookworm transmission.
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current prevalence of adult Uncinaria spp in northern fur seal callorhinus ursinus and california sea lion zalophus californianus pups on san miguel island california with notes on the biology of these hookworms
Veterinary Parasitology, 2001Co-Authors: Sharon R. Melin, Robert L Delong, Frances M. D. GullandAbstract:Abstract A prevalence survey for hookworms (Uncinaria spp.) was done in northern fur seal (Callorhinus ursinus) and California sea lion (Zalophus californianus) pups on San Miguel Island, CA, in 2000. Intestines of dead pups were examined for adult hookworms in July. These parasites were found in 95% of 20 fur seal pups and 100% of 31 sea lion pups. The number of hookworms varied from 4 to 2142 ( x =760 ) in fur seal pups and from 20 to 2634 ( x =612 ) in sea lion pups. A direct relationship was evident between body condition and number of hookworms in the pups; that is, pups in poor condition had fewer hookworms than those in good condition. There was a decline in the number of hookworms in sea lion pups in 2000 compared to collections in 1996. Eggs of Uncinaria spp. were found in rectal feces (collected in late September and early October) of none of 35 (0%) live fur seal pups and 41 of 48 (85%) live sea lion pups. Packed cell volume values, determined for most of the same live pups, were essentially normal for C. ursinus but were much lower than normal for most Z. californianus. Hookworm larvae were not found in blubber of fur seal and sea lion pups or in rookery sand in July. Rookery sand, positive for live hookworm larvae when put in a refrigerator, was negative at removal 2.5 years later. The average number of eggs in utero of female hookworms was 285 for three specimens from a fur seal pup and 281 from three specimens from a sea lion pup. One hookworm larva was recovered from milk stripped from the teats of a stranded Z. californianus female at The Marine Mammal Center, Sausalito, CA.
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current prevalence of adult Uncinaria spp in northern fur seal callorhinus ursinus and california sea lion zalophus californianus pups on san miguel island california with notes on the biology of these hookworms
Veterinary Parasitology, 2001Co-Authors: Robert L Delong, Sharon R. Melin, Frances M. D. Gulland, Anthony J Orr, E T Lyons, S C TolliverAbstract:A prevalence survey for hookworms (Uncinaria spp.) was done in northern fur seal (Callorhinus ursinus) and California sea lion (Zalophus californianus) pups on San Miguel Island, CA, in 2000. Intestines of dead pups were examined for adult hookworms in July. These parasites were found in 95% of 20 fur seal pups and 100% of 31 sea lion pups. The number of hookworms varied from 4 to 2142 (mean = 760) in fur seal pups and from 20 to 2634 (mean = 612) in sea lion pups. A direct relationship was evident between body condition and number of hookworms in the pups; that is, pups in poor condition had fewer hookworms than those in good condition. There was a decline in the number of hookworms in sea lion pups in 2000 compared to collections in 1996. Eggs of Uncinaria spp. were found in rectal feces (collected in late September and early October) of none of 35 (0%) live fur seal pups and 41 of 48 (85%) live sea lion pups. Packed cell volume values, determined for most of the same live pups, were essentially normal for C. ursinus but were much lower than normal for most Z. californianus. Hookworm larvae were not found in blubber of fur seal and sea lion pups or in rookery sand in July. Rookery sand, positive for live hookworm larvae when put in a refrigerator, was negative at removal 2.5 years later. The average number of eggs in utero of female hookworms was 285 for three specimens from a fur seal pup and 281 from three specimens from a sea lion pup. One hookworm larva was recovered from milk stripped from the teats of a stranded Z. californianus female at The Marine Mammal Center, Sausalito, CA.
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comparative biology of Uncinaria spp in the california sea lion zalophus californianus and the northern fur seal callorhinus ursinus in california
Journal of Parasitology, 2000Co-Authors: Terry R Spraker, Sharon R. MelinAbstract:Studies on several aspects of the life cycle of hookworms (Uncinaria spp.) in the California sea lion (Zalophus californianus) and northern fur seal (Callorhinus ursinus) were conducted on material collected on San Miguel Island (SMI), California and at The Marine Mammal Center, Sausalito, California in 1997, 1998, and 1999. Examination of Z. californianus intestines for adult hookworms and feces for eggs revealed that longevity of these parasites in pups is about 6–8 mo, and infections are probably not present in older sea lions. Parasitic third-stage larvae (L3) were recovered from the ventral abdominal tissue of Z. californianus, suggesting transmammary transmission. Callorhinus ursinus pups had no hookworm eggs in their feces or adult worms (except for 1 probable contaminant) in their intestines in the fall and early winter, revealing that adult Uncinaria spp. are spontaneously lost at <3 mo of age of the pups. Sand samples from rookeries, used by both Z. californianus and C. ursinus, on SMI were nega...
