The diet of the Narrowmouthed Catshark Schroederichthys bivius, from the Patagonian continental shelf

A. MASSA; VILLA A.; D. GIBERTO; J. COLONELLO; C. BREMEC; FIGUEROA D.; BELLEGGIA M.

Congreso; Joint Meeting of Ichthyologists and Herpetologists. American Elasmobranch Society (AES). Austin, Texas, EEUU; 2017

0119 Poster Session I, Rio Grande Exhibit Hall, Friday 14 July 2017Mauro Belleggia1, Agostina Villa2, Jorge Colonello3, Daniel E. Figueroa4, Agustin Giberto1, Claudia Bremec11Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina, 2Universidad de Buenos Aires (UBA), Buenos Aires, Argentina, 3Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP), Mar del Plata, Argentina, 4Laboratorio de Ictiología, FCEyN, Universidad Nacional de Mar del Plata (UNMdP), Argentina, Mar del Plata, ArgentinaLet´s Go Hunt: The Diet of The Narrowmouthed Catshark Schroederichthys bivius, from the Patagonian Continental ShelfThe narrowmouthed catshark Schroederichthys bivius is an endemic species of the southwest Atlantic and southwest Pacific continental shelf. It is distributed from Brazil to Argentina and Chile. In Argentina it occurs from 50 to 360 m depth. Food habits of S. bivius were studied based on analysis of stomach contents. Specimens were collected from two research cruises carried out by (INIDEP) during winter 2016 and summer 2017 on the southern Patagonian continental shelf (41oS - 48oS). Prey items were identified to the lowest possible taxon, counted and weighed. The percentage of the index of relative importance (%IRI) was used to evaluate the contribution of each prey. The hypothesis that the consumption of each prey group is influenced by total length, sex, maturity stage or season was assessed by fitting generalized linear models (GLM). From the 309 catsharks analyzed, all stomachs (100%) contained food. The %IRI revealed that the species fed mostly on cephalopods (36.90%) and crustaceans (33.18%), followed by fish (20.36%) and polychaetes (24%). The consumption of polychaetes and crustaceans decrease as the narrowmouthed catshark grew in size, and they were consumed more during winter than summer. On the other hand, the consumption of cephalopods increased with the total length of S. bivius and they were consumed more in summer than in winter. The trophic level was estimated 3.94.____________________________________________________________________________________________