118 



NORTH AMERICAN FAUNA 68 



Snails were recognizable in stomachs because the tough mus- 

 cular foot was usually little affected by chewing and often the 

 chitinous operculum remained intact and attached to the foot. The 

 shells of small snails (Buccinum sp.) were often swallowed but 

 those of large ones (Argobuccinum oregonensis) , except the oper- 

 culum, were not. 



Clam shells, except those from small individuals, were seldom 

 present in the stomach. One stomach contained about 2 liters of 

 clam meats, the foot and viscera of many almost intact, but not 

 one scrap of shell. The shell of thin-shelled clams (Serripes groen- 

 landicus) were fragmented and swallowed in considerable quan- 

 tity. 



The small mussel Musculus vernicosa, which was consumed in 

 large numbers, was usually swallowed whole. Individual mussels 

 may appear in the feces with the valves still intact. Many frag- 

 mented shells of larger mussels, such as Volsella volsella, some- 

 times appeared in feces. Often, however, stomachs having a number 

 of mussels contained little or no shell. The viscera were recogniz- 

 able by their orange color and attached byssus. 



The pearly monia (Pododesmus macro schisma) appeared in 50 

 stomachs, often in considerable quantity but only a few tiny 

 fragments of shell were found. Observations of feeding otters 

 revealed that, after slightly loosening the valves with one canine 

 tooth, the two valves were twisted horizontally past each other 

 between the paws so that the viscera could be quickly scooped 

 with the lower incisors and tongue from the half shell to which 

 it adhered. Seldom are the shells broken during this procedure. 

 Since few hard parts of this species are ingested, it is not re- 

 vealed as an important food species in fecal examinations. 



Octopuses are eaten with particular enthusiasm by captive otters 

 and wild otters also appear to relish them. Because of its size 

 (commonly 2 to 4 lb.), the octopus constitutes an excellent food 

 source at Amchitka. Apparently otters are not disturbed by the 

 writhing tentacles of this mollusk. Pieces of arms are bitten off 

 and eaten when one moves within range of the paws and mouth. 

 Other tentacles wrap themselves about the otter's head, legs, and 

 body while the otter continues to tear off and swallow chunks of 

 flesh (fig. 64). Occasionally a sucker attaches itself to the otter's 

 palate but it is quickly torn loose by the extended claws of the 

 forepaws. A large octopus may furnish sufficient food for more 

 than one feeding period. The chitinous beak of the octopus may 

 or may not be swallowed. Even if it is, fecal examinations do not 

 reveal the importance of this food species. 



