Feeding strategy and cannibalism of the Argentine hake Merluccius hubbsi in San Matías Gulf, Patagonia

OCAMPO REINALDO, MATÍAS; GONZÁLEZ, RAÚL; ROMERO, MARÍA ALEJANDRA

JOURNAL OF FISH BIOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2011

0022-1112

The diet composition and feeding strategy of the Argentine hake Merluccius hubbsi in San Matías Gulf were analysed, in order to use this information for the sustainable management of the fishery. M. hubbsi behaves as an opportunistic predator. Small hakes seem to be specialized in consuming planktonic crustaceans, whereas medium and large hakes showed numerous prey-groups with low frequency of occurrence and variable specific abundance. Intra- and intercohort cannibalism was detected in all sizes and particularly significant in large hakes. Medium sized hake consumed small hakes and large sized hake consumed both small and medium hakes. These results allow us to propose that the removal of large hakes by fishing may increase the risk of overfishing throughout two combined effects: a direct effect of recruitment-overfishing and an indirect effect of growth-overfishing through an enhanced cannibalism of medium hakes on small hakes. Due to its high importance, intra- and intercohort cannibalism and other trophic relationships in the M. hubbsi should be considered explicitly in stock assessment models.