Feeding habits of southwestern Atlantic wreckfish Polyprion americanus (Polyprionidae, Teleostei)

Abstract

This paper describes the diet and feeding habits of southwestern Atlantic wreckfish Polyprion americanus (28º-34º40’S, 70-510m deep). Stomach contents and on deck regurgitates from commercially caught wreckfish were examined. Sixteen species of fish, eight of cephalopods and one crab were identified among the 429 food items examined. Main wreckfish prey included the hake Merluccius hubbsi, the argentine shortfin squid Illex argentinus and the red-crab Chaceon notialis. Wreckfish juveniles consumed fish (79%) and squid (21%). Adults consumed less fish (13%), and more crab (47%) and squid (40%). At spawning areas and season, adult wreckfish consumed mainly ommastrephid squids (80%). Half of the prey species were pelagic or benthic-pelagic which agrees with fishers’ statement that wreckfish performs some vertical movement (100-150m), at night. Teeth are small and villiform. Five patches of teeth were observed on the tongue: a large posterior one and four smaller anterior ones; different from three patches arranged in a triangle, described for North Atlantic stock. The mouth is protractile and preys is swallowed whole by suction. For each fishing trip sample, there was only one dominant prey species suggesting that feeding strategy must include efficient location of food concentrations.