IIMYC   23581
INSTITUTO DE INVESTIGACIONES MARINAS Y COSTERAS
Unidad Ejecutora - UE
artículos
Título:
Big fish (and a smallish skate) eat small fish: diet variation and trophic level of Sympterygia acuta, a medium-sized skate high in the food web
Autor/es:
BARBINI, SANTIAGO A.; LUCIFORA, LUIS O.
Revista:
MARINE ECOLOGY-PUBBLICAZIONI DELLA STAZIONE ZOOLOGICA DI NAPOLI I
Editorial:
WILEY-BLACKWELL PUBLISHING, INC
Referencias:
Lugar: Nápoles; Año: 2016 vol. 37 p. 283 - 293
ISSN:
0173-9565
Resumen:
p { margin-bottom: 0.25cm; direction: ltr; color: rgb(0, 0, 10); line-height: 120%; text-align: left; widows: 2; orphans: 2; }p.western { font-family: "Calibri",serif; font-size: 11pt; }p.cjk { font-family: "Droid Sans Fallback"; font-size: 11pt; }p.ctl { font-family: "DejaVu Sans"; font-size: 11pt; }a:link { color: rgb(0, 0, 255); } The bignose fanskate, Sympterygia acuta, is a small-to-medium-sized species endemic to shallow coastal waters of the Southwest Atlantic. S. acuta displays a clear seasonal reproductive cycle, characterized by a maximum egg laying activity in spring and hatching in summer. We hypothesize that diet and feeding activity change with maturity stage and season and that, given its smallish size, the trophic level is low. Using a multiple-hypothesis modeling approach, the diet of S. acuta in relation with sex, body size, maturity stage, region (i.e. north and south) and season was analyzed; and a potential relationship between feeding activity and the seasonal reproductive cycle was assessed. S. acuta fed on a broad spectrum of prey, but teleosts were more important (47.97% index relative importance , %IRI) followed by decapods (39.84 %IRI), cumaceans (8.31 %IRI) and isopods (1.89 %IRI). Maturity stage was a strong determinant of the ontogenetic diet shift of S. acuta, associated to region and season. Feeding activity was higher in the cold season than in the warm season, and was less important in the south region than in the north region. Unexpectedly, the specific trophic level was high (3.87). S. acuta shifts its diet with maturity stage possibly by a combination of an improved ability to capture prey and a change in energy demand of mature individuals. Despite being a small-to-medium-sized skate,S. acutashowed a trophic level similar to that oflarge-bodied marine predators. It reduces its feeding activity seasonally, because in the warm season this species may experience and increased predation risk from large sharks.