Food and Feeding Habits of Skipjack Tuna (Katsuwonus pelamis) from the Marquesas and Tuamotu Islands

Abstract

Stomach samples were examined from 603 skipjack (Katsuwonus pelamis) caught by live-bait fishing in waters surrounding the Marquesas and Tuamotu Islands from 1957 to 1959. The principal crustacean food consisted of stomatopods and megalops, while the main molluscan item was squid. The major fish items were acanthurids, gempylids, lutjanids, nomeids, scombrids, serranids, and synodontids. Larger skipjack ate comparatively more fish and less crustaceans. As expected, those from inshore areas had eaten more reef-originating organisms than had skipjack from areas farther offshore. No differences were found in food of the two sexes. Skipjack appeared to have heavy feeding periods in midmorning and in late afternoon hours, with a slack period during midday. This feeding pattern may be related: (1) to the distribution and abundance of forage organisms and zooplankton and their diurnal movements or (2) to a satiaton of the food drive during midday. Confirmation of some of the trophic links in the food chain of skipjack was obtained by examination of the stomachs of the ingested fishes. The occurrence of juvenile tuna in the skipjack stomachs was higher than those reported from previous food studies of tuna from other areas.