FEEDING HABITS OF Engraulidae anchoita LARVAE OFF SOUTHERN BRAZIL

Abstract

The aim of this work was to investigate the feeding habits of Engraulis anchoita larvae off the extreme south of Brazil. Samples were collected using 60 cm Bongo net (300 mm mesh aperture) during the different seasons of the year: spring, summer, autumn and winter (1987-1991). A total of 1231 larvae (2.8-34 mm SL) were analyzed. The smallest larva with gut contents was 3.4 mm long; forty percent of the larvae, 3.4-4 mm long, had at least one item in their guts. A reduction of the feeding incidence in larvae 6-8 mm was observed, suggesting that this could be a critical period for survival. Copepod nauplii, copepod adults, invertebrate eggs and copepodites were the main items identified in the larval diet. Starch grains and fungal spores were also found among gut contents. The structure of the branchial arches suggests that filtration of small particles is not an adequate feeding method for the larvae. High feeding incidences occurred during the night, with items probably ingested through a passive mechanism. Winter is suggested as the most favorable season for larva I feeding, with high probability of prey consumption due to shelf break upwelling, high vertical stability in the water column, and to high production in the coastal region. The current study on larval feeding habits contributes to a better understanding of the dynamics of this species that dominated the ichthyoplankton and pelagic nektonic community in this region during those periods.