Diet of Illex argentinus in coastal waters: the case of the Spring and Summer Spawning Groups inhabiting San Matias Gulf (Northern Patagonia, Argentina).

CRESPI ABRIL, AUGUSTO CÉSAR; MARÍA MAGADALENA TRIVELLINI

AQUATIC BIOLOGY

INTER-RESEARCH

Año: 2011

1864-7790

To study the diet of two coastal spawning groups of Illex argentinus, we analyzed the stomach content of 3645 specimens (10 cm to 36 cm of mantle length). More than half (58%) of observed stomachs were empty. There were no differences in the prey consumed between specimens of different sex and maturity stages. Additionally, no differences were observed in the diet among individuals belonging to Summer and Spring Spawning Groups. The most frequent prey item was fishes (0.79 frequency of occurrence), followed by cephalopods (0.18 frequency of occurrence) and lastly by crustaceans (0.09 frequency of occurrence). The seasonal variation of empty stomachs frequency and the mean stomach fullness revealed that squids fed more actively in spring and summer, mainly preying upon small pelagic fishes.