Contribution to the knowledge on the diet, feeding activity, and reproduction of Lolliguncula brevis (BLAINVILLE, 1823) in the coastal region off Santos (São Paulo State)

Abstract

This study aimed to investigate the diet and feeding activity of the squid Lolliguncula brevis in the coastal region of Santos. Sex ratio and maturity stages of the specimens were also evaluated. The sampling was carried out in September 2005 and March 2006 in Santos Bay and the continental shelf off Santos. A total of 181 specimens with 17 to 50 mm of mantle length were caught between the depths of 8.9 and 26.5 m. The sex ratio was 1.7 females:1 male; males attain gonadal maturity at smaller size than females. In both periods, most males were mature, the smallest of them measuring 23 mm of mantle length. The smallest mature female measured 32 mm, while all females larger than 40 mm were mature. The results of the digestion degree, the fullness degree and the fullness index suggest that the food intake occurs throughout the day, but with higher intensity at dusk. However, samples from the dark period of the day were not collected. The items identified in the stomach contents were crustaceans, bony fish, cephalopods, bryozoans, and nematodes. Crustaceans were the most important food for all size classes. However, as the squid body enlarged, the importance of fish in the diet increased and that of crustaceans decreased. The relative contribution of crustaceans in the diet was greater during the afternoon and dusk, and that of fish during the morning.