THE SEA OTTER IN THE EASTERN PACIFIC OCEAN 271 



4. Both the aging animals and juveniles, forced to utilize poor 

 quality foods, were further hindered in feeding activities by sus- 

 tained periods of rough seas. Aging adults, and juveniles deserted 

 by mothers, after exhausting accumulated summer and fall re- 

 serves of body fat, developed enteritis v^hich is typical of that 

 found in other species of animals under conditions of starvation 

 and stress (see Parasites and Miscellaneous Diseases). 



5. Adult otters at Amchitka w^eighed less than otters from less 

 crowded populations (see Body Measurements). 



6. When weakened animals exhibiting symptoms of enteritis 

 (black feces) were captured and placed in a pool of clean water 

 where they were furnished adequate food, some of them regained 

 health. After they were introduced to a diet of fish, all of these 

 captives refused to eat sea urchins and most hard-shelled mollusks. 

 The gastrointestinal tract of similar animals that died on beaches 

 either were empty, or contained only hard-shelled organisms. 



PARASITES AND MISCELLANEOUS DISEASES 



Both in the wild and in captivity sea otters are afflicted by a 

 variety of pathological conditions. Systematic, long-term studies 

 of pathology were not undertaken, but animals found dead or 

 dying on beaches were examined (Rausch and Locker, 1951; 

 Rausch, 1953) and observations of captives were recorded (Kirk- 

 patrick, et al., 1955; Kenyon, Yunker, and Newell, 1965). Jellison 

 and Neiland (1965, p. 8-9) list the parasites of sea otters. In the 

 following sections these studies are reviewed briefly and additional 

 observations are presented. 



Most sea otters found dead on Amchitka Island displayed ter- 

 minal symptoms of enteritis. Other pathological conditions, such 

 as neoplastic and degenerative changes in the liver, ulceration of 

 the jaws and alveoli of the teeth, and infections of the paws also 

 occurred. 



Internal (helminth) parasites 



More than 30 sea otters found dead or in moribund condition on 

 Amchitka beaches in 1949, 1951, and 1952 were studied by Rausch 

 (Rausch and Locker, 1951 ; Rausch, 1953). The helminths recorded 

 from these were : (Cestoda) Pyramicocephalus phocarum (Fabri- 

 cius, 1780) ; (Trematoda) Orthosplanchnus f rater culm Odhner, 

 1905, Phocitrema fusiforme Goto and Ozaki, 1930, Pricetrema 

 zalophi (Price, 1932), Microphallus pirum (Afanas'ev, 1941); 

 (Nematoda) Terranova (Porrocaecum) decipiens (Krabbe, 1873) ; 

 (Acanthocephala) Corynosoma strumosum (Rudolphi, 1802). 



