Food of the Pacific cod Gadus macrocephalus Tilesius near Kodiak Island, Alaska

Abstract

The Pacific cod, Gadus macroaephalus, from the Kodiak Alaska continental shelf, feeds predominantly on demersal fishes and crustaceans. The most frequently occurring food groups in Pacific cod stomachs in order of decreasing frequency of occurrence are fishes, crabs, shrimps and amphipods. The snow crab, Chionoecetes bairdi, is the most frequently occurring food species. Frequency occurrence of food items in cod stomachs is enumerated within each of three cod size groups - 33 to 52 cm, 53 to 72 cm, and 73 to 92 cm. Fishes and cephalopods increase in frequency occurrence with increasing cod size. Amphipods and polychaetes are more frequently found in smaller fish. In general, the incidence of euphausiids and mysids decrease with increasing cod size. Crabs, shrimps, pelecypods and gastropods increase in frequency occurrence from the small (33 to 52 cm) to the medium size fish (53 to 72 cm) and again decline in importance among larger cod (73 to 92 cm).