230 



NORTH AMERICAN FAUNA 74 



Table 38. Helminthic parasites of the Pacific walrus/ 









No. per 



Frequency 





Location 



Sample 



walrus 



or occur- 



Species 



in body 



size 



(range) 



rence {%) 



TREMATODA 











Ohdneriella rossica Skriabin 



Liver 



? 



? 



?b 



Orthosplanchnus arcticus Ohdner 



Liver 



95 



1-7 



3.2 



Orthosplanchnns fraterculm Ohdner 



Liver 



95 



1-27 



8.4 



Orthosplanchnus gracilis Treschev and 











Yurakhno 



Liver 



95 



4 



1.05 



Ortnosplanchnus odobaem Treschev, 











Serdiukov, and Yurakhno 



Liver 



95 



1-130 



31.6 



lllUcifJlUllLilniMS UmiUllMi lUldKIlIlU 



lIllcaLlllt; 









Microphallus orientalis Yurakhno 



Intestine 



95 





14.7 



CESTODA 











Diphyllobothrium cordatum (Leuckart) 



Intestine 



95 



1-9 



9.5 



Dtphyllobothrium lanceolatum (Krabbe) 



Intestine 



OO 





1 7c 



Diphyllobothrium rduieri (Zschokke) 



Intestine 



95 



16 



1.05 



NEMATODA 











Contracaecum osculatum (Rudolphi) 



Stomach 



? 



? 



?d 



Phocanema decipiens (Krabbe) 



Stomach 



202 



1-25 



4.4e 



Trichinella spiralis Owen 



Skeletal muscle 



131 





1.5f 



ACANTHOCEPHALA 











Corynosoma validum Van Cleave 



Intestine 



95 



1-265 



89.5 



^From Yurakhno and Treschev (1972), except as noted. 

 ^Reported only by Skriabin (1915) in Deliamure (1955). 

 '^Reported only by Deliamure and Popov (1975). 

 ^Reported only by Deliamure (1955). 



eFrom Yurakhno and Treschev (1972) (N = 95, 1.05%) and L. M. Shults (unpublished 

 data) (N = 107, 7.5%). 



fFrom Yurakhno and Treschev (1972) (N = 27, 3.7%), Rausch et al. (1956) (N = 51,0%), 

 and Fay (1960) (N = 53, 1.9%). 



Microbiological Infections 



Derm atomy cosis 



In a sample of 29 animals that I examined, 9 had dermatomycotic lesions on 

 the hind flippers, 1 also had lesions on the fore flippers, and 2 had lesions on the 

 abdomen. This condition appears as dark, ring-like blotches, often with several 

 lesions interconnected (Fig. 132). Histological preparations from one of the 

 abdominal lesions and several of those on the flippers disclosed that the fungal 

 hyphae had invaded only the epidermis, causing partial exfoliation of the 

 cornified layer, occasionally to the depth of the granular layer. Conceivably, in 

 severe cases, this infection might cause intense irritation and exposure of the 

 underlying epidermal layers. It also may predispose the animal to invasion of 

 other infectious agents and irritants. The most extreme case that I observed was 

 of a 10-month-old calf, in which about one-third of the body surface was marked 



