A COMPARATIVE-STUDY OF THE DIET OF LOLIGO-VULGARIS (LAMARCK, 1799) (MOLLUSCA, CEPHALOPODA) FROM THE SOUTH COAST OF PORTUGAL AND THE SAHARANBANK (CENTRAL-EAST ATLANTIC)

This paper presents data on the diet of the squid, Loligo vulgaris (La marck, 1799) from the south coast of Portugal (Algarve) and from the S aharan Bank (Central-East Atlantic), A total of 964 squid was collecte d from the Algarve coast, between March 1993 and October 1994, from bo ttom trawling. An additional sample of 70 stomachs was obtained in the Algarve coast from the hand jigging fishery during 1991 and 1992. In the Saharan Bank, 848 squid were obtained, between June 1993 and Janua ry 1994, with bottom trawling. Stomachs with contents for trawled squi d from the Algarve coast, and the Saharan Bank represented 28.1% and 4 0.8%, respectively. Fish was always the main component of the diet in both regions, representing 88.6% of the total weight of the prey found in the stomachs, for the Algarve coast, and 70.9% for the Saharan Ban k. The occurrence percentage and the percentage in number indicated th at Trachurus trachurus and fish belonging to the family Gobiidae were the most frequent fish found in the Algarve samples, while flatfish we re the most common fish in the Saharan Bank samples, Loligo vulgaris w as the dominant cephalopod found in the stomachs for both regions. No differences in the diet were found between males and females. The comp arison between immature and mature squid showed that the importance of fish was higher in mature squid, for both regions. The squid captured from the Algarve coast by bottom trawling (at greater depths and offs hore) fed primarily on fish, while those captured with hand jigging (i nshore, at lower depths) contained an important percentage of crustace ans. (C) 1997 Elsevier Science B.V.