DAO 42:111-117 (2000)  -  doi:10.3354/dao042111

Prey, parasites and pathology associated with the mortality of a juvenile gray whale (Eschrichtius robustus) stranded along the northern California coast

Murray D. Dailey1,*, Frances M. D. Gulland1, Linda J. Lowenstine2, Paul Silvagni2, Daniel Howard3

1The Marine Mammal Center, 1065 Fort Cronkhite, Sausalito, California 94965, USA
2Veterinary Medicine Teaching Hospital, Veterinary Pathology, Microbiology And Immunology, University of California at Davis, Davis, California 95616, USA
3Gulf of the Farallones National Marine Sanctuary, San Francisco, California 94123, USA

ABSTRACT: An eastern Pacific gray whale (Eschrichtius robustus) stranded off Pelican Point, Tomales Bay, California, USA, was examined for physiological parameters, prey, parasites and associated pathology. The whale was emaciated, and hematological examination revealed an elevation in hematocrit, serum sodium, potassium, electrolyte values and hypoglycemia. Parasites recovered included 5 species, 1 ectoparasite (Cyamus scammoni), and 4 helminths (Anisakis simplex, Ogmogaster antarcticus, Ogmogaster pentalineatus, Bolbosoma balanae) with the latter causing multifocal transmural abscesses. Histological examination indicated severe acute lung congestion, minimal, multifocal, lymphocytic, interstitial myocarditis, and mild hepatocellular and Kupffer cell hemosiderosis. The prey taxa present in the stomach indicated the whale was feeding on hard bottom communities prior to death.

KEY WORDS: Cetacean stranding · Pacific gray whale · Eschrichtius robustus · Hematology · Pathology · Parasites · Prey species

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