408 



Fishery Bulletin 97(2), 1999 



Discussion 



On the basis of our sampling of stomach contents, 

 sleeper sharks appear to feed mainly on the bottom. 

 Even though Octopus dofleini represented only 5% 

 of the total stomach content weight, they occurred 

 in a high percentage of sleeper shark stomachs ( 739^ ). 

 Other researchers have also found that benthic fish 

 and invertebrates are the predominate species in the 

 diet of sleeper sharks. Phillips ( 1953) found a sleeper 

 shark in California that had fed on rockfish. Gotshall 

 and Jow (1965) found that the diet of sleeper shark 

 included rex sole, Glyptocephalus zachirus; Dover 

 sole, Microsto77Jus pacificus; Pacific halibut, 

 Hippoglossus stenolepis: and cephalopods. 



The diet of sleeper sharks vary with their size. 

 Gotshall and Jow (1965) described the main food of 

 a 114-cm female sleeper shark as Moroteuthis ro- 

 busta. In our study lengths of sleeper sharks ranged 

 between 200 and 300 cm. Their diets consisted mainly 

 of arrowtooth flounder, walleye pollock, and cepha- 

 lopods. Larger sleeper sharks (360-400 cm) have 

 been reported to consume not only fishes and cepha- 

 lopods, but also marine mammals, i.e. harbor seal 

 (Bright, 1959) and southern right whale (Crovetto 

 etal., 1992). 



We would like to note that stomach samples used 

 in our study were from the area southwest of Kodiak 

 Island, close to Steller sea lion iEumetopias jubatus) 

 rookeries at Chowiet and Chirikof Islands, as well 

 as near numerous sea lion haulouts (Sease et al., 

 1993; NMFS, 1995). However, sleeper shark attacks 

 on pups have not been reported at any time of year 

 and we did not find evidence of predation on sea li- 

 ons in our study. We did find fish offal (five arrowtooth 

 flounder heads) in stomach samples. Bigelow and 

 Schroeder ( 1948) also reported that Greenland shark, 

 Somniosus microcephalus (a similar congeneric spe- 

 cies of sleeper shark in the Atlantic Ocean), devours 

 carrion, such as whale meat and blubber from whal- 

 ing operations. It seems that sleeper shark, like 

 Greenland shark, is sluggish and likes to stay on the 

 bottom, feeding opportunistically on what they en- 

 counter in the environment (including carrion and 

 fish offal). 



Acknowledgments 



We would like to thank Lowell Fritz, Patricia Livings- 

 ton, John Sease, and three anonymous referees for 

 reviewing this manuscript. 



Literature cited 



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