title: Comparative biology of Uncinaria spp. in the California sea lion (Zalophus californianus) and the northern fur seal (Callorhinus ursinus) in California.
abstract: 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 negative for free-living, L3 in summer months but positive in fall and winter months, indicating seasonality occurred.
authors.affiliation: Department of Veterinary Science, Gluck Equine Research Center, University of Kentucky, Lexington 40546-0099, USA.
authors.forename: E T
authors.initials: ET
authors.lastname: Lyons
authors.forename: R L
authors.initials: RL
authors.lastname: DeLong
authors.forename: F M
authors.initials: FM
authors.lastname: Gulland
authors.forename: S R
authors.initials: SR
authors.lastname: Melin
authors.forename: S C
authors.initials: SC
authors.lastname: Tolliver
authors.forename: T R
authors.initials: TR
authors.lastname: Spraker
mesh_terms: D000273:Adipose Tissue / Q000469:parasitology; D000723:Ancylostomatoidea / Q000254:growth & development / Q000502:physiology*; D000818:Animals; D002140:California; D005243:Feces / Q000469:parasitology; D005260:Female; D006725:Hookworm Infections / Q000469:parasitology / Q000635:transmission / Q000662:veterinary*; D018445:Infectious Disease Transmission, Vertical / Q000662:veterinary; D007422:Intestines / Q000469:parasitology; D008018:Life Cycle Stages; D008297:Male; D008321:Mammary Glands, Animal / Q000469:parasitology; D046070:Sea Lions / Q000469:parasitology*; D012621:Seasons; D012987:Soil / Q000469:parasitology; D013997:Time Factors
chemical_list: D012987:Soil