FEEDING DYNAMICS OF OCTOPUS-MIMUS (MOLLUSCA, CEPHALOPODA) IN NORTHERNCHILE WATERS

The natural feeding of 485 Octopus mimus (164 to 3088 g) was studied i n relation to the species' life cycle and environmental seasonal varia tions off the north of Chile from autumn 1991 to summer 1992. Analysis of digestive-tract contents revealed that O. mimus preyed upon 25 dif ferent prey items belonging to five zoological groups (Teleostei, Moll usca, Crustacea, Echinodermata and Polychaeta). Cannibalism was only o ccasional. The results indicate that the diet and food intake of this species are significantly affected by sex and maturation. Senescent in dividuals ingest a small amount of food, and their diet is mainly base d on small, not very motile prey. The food intake, expressed as body w eight, of non-senescent individuals is higher in females than in males . Seasonal changes in sea-water temperature seem to be followed by adj ustments in food intake. Like other Octopus species, O. mimus appears to be an opportunistic predator.