Analysing the feeding strategy of Bassanago albescens (Barnard, 1923) in waters of Argentina

IZZO, L.; BLASINA, G.; FIGUEROA, D.

Rhode Island,

Conferencia; Joint Meeting of Ichthyologists and Herpetologists; 2010

Bassanago albescens inhabits the Argentine continental shelf between the 35 and 45°S, it presents a high biomass, enclosed environmental niche and benthic trophic habits. This species is caught as bycatch in trawling fisheries targeting Argentine hake, Merluccius hubbsi, and in next years, it can represent an interesting alternative before the collapse of the traditional fisheries. The present study analyzes the diet of B. albescens and determines its feeding strategy, from the analysis of the stomach contents. Samples used were obtained from research cruises conducted in two regions of the southwest Atlantic: south (43ºS?51ºS) and north (35°S-41°S). Total length and sex of each specimen were recorded, and it was observed that males are smaller than females. The importance of each prey, the feeding strategy and niche width contribution were determined for a total of 219 stomachs. The results showed that B. albescens have a wide food niche and it was composed by fishes, mollusks, crustaceans, equinoderms and polychaetes. In the present study, the diet of this species varies among regions. The squid, isopods, gammarid amphipods and teleosts were the mainly food items in south area. On the other hand, in north area the main preys ingested were the crabs, the ophiuroids, hyperiid amphipods and polychaetes. Bassanago albescens is a generalist predator although the dominant preys change along their geographical distribution. This pattern is a reflection of the plasticity to exploit peaks in prey abundance of this species, show an opportunist behavior.