Abstract
Intestines of California sea lion (Zalophus californianus) pups (n= 204), born in 2002 on San Miguel Island, California, were examined for hookworms (Uncinaria spp.) as part of a seasonal mortality study from June through December 2002 and January 2003. The investigation was planned to coincide with most of the previously established hookworm infection period of the pups. Prevalence of hookworms in dead pups was 100% for each month of the study. The geometric mean intensity of infections per month was: 94.03 (n=30) for June, 629.09 (n=50) for July, 319.90 (n=31) for August, 159.90 (n=30) for October, 109.03 (n=30) for November, 37.84 (n=24) for December 2002 and 11.05 (n=9) for January 2003. In addition to the temporal pattern, the infection intensity was higher for pups in good condition and for male pups. An inter-year comparison of hookworm counts from dead pups collected in July of 1996, 2000, and 2002 also demonstrated higher intensity in pups in better condition but sex-differences in intensity were inconsistent across years. The inter-year comparison also demonstrated higher intensities in dead pups collected from portions of the rookery with sandy substrate versus rocky substrate. No annual differences in intensity were found after adjusting for substrate and condition.
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References
Arnould PYJ (1995) Indices of body condition and body composition in female Antarctic Fur seals (Arctocephalus gazella). Mar Mammal Sci 11:301–313
Lyons ET (1963) Biology of the hookworm, Uncinaria lucasi Stiles, 1901, in the northern fur seal, Callorhinus ursinus Linn. on the Pribilof Islands, Alaska. Dissertation, Colorado State University, Ft. Collins, CO, 97 pp, 5 pls
Lyons ET, DeLong RL, Melin, SR, Tolliver SC (1997) Uncinariasis in northern fur seal and California sea lion pups from California. J Wldf Dis 33:848–852
Lyons ET, DeLong RL, Gulland FM, Melin SR, Tolliver SC, Spraker TR (2000) Comparative biology of Uncinaria spp. in the California sea lion (Zalophus californianus) and the northern fur seal (Callorhinus ursinus) in California. J Parasitol 86:1348–1352
Lyons ET, Melin SR, DeLong RL, Orr AJ, Gulland FM, Tolliver SC (2001) 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. Vet Parasitol 97:309–318
Lyons ET, Delong RL, Spraker TR, Melin SR, Tolliver SC (2003) Observations in 2001 on hookworms (Uncinaria spp.) in otariid pinnipeds. Parasitol Res 89:503–505
Melin SR (2002) The foraging ecology and reproduction of the California sea lion (Zalophus californianus californianus). PhD Dissertation. University of Minnesota, St. Paul, p 150
Nadler SA, Adams BJ, Lyons ET, DeLong RL, Melin SR (2000) Molecular and morphometric evidence for separate species of Uncinaria (Nematoda: Ancylostomatidae) in California sea lions and northern fur seals: Hypothesis testing supplants verification. J Parasitol 86:1099–1106
Olsen OW (1958) Hookworms, Uncinaria lucasi Stiles, 1901, in fur seals (Callorhinus ursinus) (Linn.), on the Pribilof Islands. Tr 23rd N Amer Wildl Conf 3–5 Mar 1958, pp 152–175
Olsen OW, Lyons ET (1962) Life cycle of the hookworm, Uncinaria lucasi Stiles, of northern fur seals, Callorhinus ursinus, on the Pribilof Islands in the Bering Sea. J Parasitol 48(suppl):42–43
Olsen OW, Lyons ET (1965) Life Cycle of Uncinaria lucasi Stiles, 1901 (Nematoda: Ancylostomatidae) of fur seals, Callorhinus ursinus Linn., on the Pribilof Islands, Alaska. J Parasitol 51:689–700
R Development Core Team (2004) R: a language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. ISBN 3-900051-00-3, URL: http://www.R-project.org
Sepúlveda MS, Alcaíno H (1993) Fauna helmintológica en el lobo fino de Juan Fernández, Arctocephalus philippii (Peters, 1866). Parasitología al Día 17:19–24
Spraker TR, Lyons ET, DeLong RL, Zink RR (2004) Penetration of the small intestine of a California sea lion (Zalophus californianus) pup by adult hookworms (Uncinaria spp). Parasitol Res 92:436–438
Zar JH (1996) Biostatistical analysis, 3rd edn. Prentice-Hall, New Jersey
Acknowledgements
This research (paper No. 04-14-042) is published with the approval of the director of the Kentucky Agricultural Experiment Station. We acknowledge the assistance of Brian Aldridge, Christie McKnight, Frances Gulland, and Melissa Schutten, who performed necropsies. The study was conducted under Marine Mammal Protection Act Permit No. 782-1613, issued to the National Marine Mammal Laboratory, Seattle, WA, USA
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Lyons, E.T., DeLong, R.L., Spraker, T.R. et al. Seasonal prevalence and intensity of hookworms (Uncinaria spp.) in California sea lion (Zalophus californianus) pups born in 2002 on San Miguel Island, California. Parasitol Res 96, 127–132 (2005). https://doi.org/10.1007/s00436-005-1335-5
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DOI: https://doi.org/10.1007/s00436-005-1335-5