Food habits of bait-caught skipjack tuna Katsuwonus pelamis off the Canary Islands
A.G. Ramos, J.M. Lorenzo and J.G. Pajuelo

Stomach contents of skipjack tuna 46-70 cm in total length and caught off the Canary Islands by live bait between May 1988 and January 1991 were analyzed. Of the 400 stomachs examined, 33.7% (135) were empty. In the remaining stomachs (265),59.4% of the prey were digested while 40.6% were undigested. All the undigested prey were consumed as live bait and consisted of chub mackerel Scomber japonicus(76.9%), sardine Sardina pilchardus (10.7%), bogue Boops boops (7.3%)and silverside Atherina presbyter (5.1%). Digested food was only chubmackerel. Of this prey, a part was consumed as bait (36.1%) and the remaining as natural food (63.9%). Adult skipjack were not found to feed on their young. Chub mackerel consumed as natural food ranged between 14 and 25 cm in total length. Skipjack 46-58 cm in total length fed on chub mackerel 14-19 cm while larger skipjack preyed on chub mackerel 18-25 cm. The percentage of body mass ingested bythe skipjack was enough to sustain its condition index at an optimum level.

Keywords: Skipjack tuna, Katsuwonus pelamis, food habits, Canary Islands.
Contents of this volume Sci. Mar. 59(3-4) : 365-369 Back PDF
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