| Summary: | Feeding habits of 7995 individuals of three wolffish species distributed in the north Atlantic were analyzed: 1016 of northern wolffish (Anarhichas denticulatus), 4783 of Atlantic wolffish (A. lupus) and 2196 of spotted wolffish (A. minor). The individuals sampled were taken in the NAFO Area Divisions 3NO in spring in the period 2002-2005, Div. 3L in summer in the period 2003-2004, Div. 3M in summer in the period 1993-2005, and in the ICES Area Div. IIb in autumn in the period 2004-2005. Feeding intensity was higher in the NAFO Area than in the northeast Atlantic (spring-summer vs. autumn), mainly in spotted wolffish in Div. 3M. The importance of each prey taxa was evaluated using the weight percentage. Wolffish species diet showed geographical differences. Ontogenic diet changes and prey variation through the studied period were observed, mainly in Atlantic and spotted wolffishes. This two species preyed primarialy on bottom (echinoderms, gastropods and bivalves) and benthopelagic (northern shrimp and redfish) organisms on Flemish Cap and Grand Bank. However fish and northern shrimp predation were more important on the Flemish Cap, mainly in spotted wolffish, showing periods with higher predation on these prey when the biomass of these prey species increased. This fact might have been the cause of diet overlap between Atlantic and spotted wolffishes in some periods in Div. 3M. Less ontogenic, annual and geographical diet variations were found in northern wolffish in NAFO Area, feeding mainly on ctenophores; however in Svalbard area, this species showed to be highly piscivore. Three species showed cannibalism but only in the Div. 3M.
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