Nine dolphins (two Lissodelphis borealis and seven Delphinus delphis) , killed incidentally by the driftnet fishery in the North Pacific Ocean, were collected during the periods from May to August 1991 and from September to November 1992. Stomach contents of each animal were weighed, sorted, examined, and counted. Prey species were identified to the lowest possible taxon. One stomach of D. delphis contained only a milky substance. In the other six of D. delphis and the two stomachs of L. borealis, fish otoliths numerically comprised 94% and 89% of the diet contents, respectively. Myctophid fish were the most abundant and commonly occurring fish group and numerically comprised 89% (L. borealis) and 95% (D. delphis) of all fish prey found. Among thirty-three fish prey species belonging to twelve families, Ceratoscopelas warmingi and Lampanyctus jordani were the most common and abundant species. Squid comprised proportionately less < 11%) of these dolphins' diet. Among thirteen species belonging eight families, the most common and dominant squid species were Abraliopsis felis and Onychoteuthis borealijaponica.
Delphinus delphis, Lissodelphis borealis, Stomach contents, North Pacific Ocean
