Sea Lion Zalophus Californianus Pups Research Articles

Prevalence and characterization of Salmonella spp. among marine animals in the Channel Islands, California

Salmonella enterica is a zoonotic pathogen that has been isolated from free-ranging marine mammals throughout the world, with animals in the Channel Islands of California (USA) showing the highest prevalence. The goal of this study was to determine prevalence, antimicrobial sensitivity and genetic similarity using pulsed-field gel electrophoresis (PFGE) of Salmonella in several non-domestic animal species on San Miguel and San Nicolas Islands. Fecal samples were collected from 90 California sea lion Zalophus californianus pups, 30 northern elephant seal Mirounga angustirostris pups and 87 western gulls Larus occidentalis in the Channel Islands and 59 adult male sea lions in Puget Sound, WA (USA). Salmonella were isolated, identified and serotyped, followed by antimicrobial susceptibility testing and PFGE. Of the California sea lion pups that were sampled on the islands, 21% (n = 19) were positive for Salmonella, whereas no adults males in Puget Sound were positive. Of the northern elephant seal pups sampled, 87% (n = 26) were harboring Salmonella. Only 9% (n = 8) of western gulls were shedding Salmonella, with one of these gulls harboring the only antimicrobial resistant isolate. The serotypes found in these animals were Enteritidis, Montevideo, Newport, Reading, and Saint Paul. The only serotype that showed variation on PFGE was Newport. The pinnipeds of the Channel Islands harbor Salmonella at a higher prevalence than pinnipeds from other geographic areas observed in previous studies. Researchers and veterinarians should exercise increased caution when working with these animals due to the zoonotic potential of Salmonella.

Milk and Energy Intakes of Suckling California Sea Lion Zalophus californianus Pups in Relation to Sex, Growth, and Predicted Maintenance Requirements

Isotope dilution was used to measure milk intake of 43 California sea lion pups on San Nicolas Island, California, from 1982 to 1984. Deuterium concentration was monitored in serial blood samples collected at about 5-day intervals for 3 wk after isotope administration. Estimated milk intakes differed significantly between male (723 ± 31.0 g ․ day⁻¹) and female (609 ± 24.0 g ․ day⁻¹) pups but did not increase from the first to second month postpartum. On a metabolic size basis (weight0.83), gross energy intakes did not differ between male and female pups but did differ between years, apparently as a consequence of the 1983 El Nino. The mean energy intakes (kcal ․ day⁻¹) of sea lion pups in the first (61 · W0.83) and second (308 · W0.83) months were high relative to terrestrial species. Regression of energy intake on growth rate predicted that maintenance energy requirements (kcal ․ day⁻¹) were also high (168 and 252 · W0.83 in the first and second months). The fact that California sea lion pups devote a la...