Temporal and sexual effects in the feeding ecology of the marbled sand skate Psammobatis bergi Marini, 1932

SAN MARTÍN, M JIMENA; BRACCINI, M.; TAMINI, L.; CHIARAMONTE, GUSTAVO ENRIQUE; PEREZ, J.

Marine Biology

Springer-Verlag

Año: 2007 p. 505 - 513

1432-1793

Temporal and sexual effects in feeding ecologywere examined in the marbled sand skate (Psammobatisbergi). Of 137 stomachs analysed, 130 (95%)contained food. Among these, >50% containedbetween 2 and 4 items, with a maximum of 18 preyitems found. Thirty taxonomic levels of prey itemswere identified: 18 crustaceans, 5 polychaetes, 3 molluscs,3 teleosts, and 1 chondrichthyan. Coenophthalmustridentatus and unidentiWed Brachyura were thedominant prey items by number, frequency of occurrenceand index of relative importance (IRI). Libiniaspinosa was the dominant item by mass and third mostimportant by %IRI. Psammobatis bergi consumedmostly brachyurans and showed little variability inoverall mean prey importance, hence, only a smallnumber of stomachs was needed for a precise descriptionof its dietary composition. There was no interactionbetween season and sex in the diet composition ofP. bergi and there were no differences between thediets of males and females during winter and spring.However, a seasonal pattern was found. The mostimportant prey in spring was C. tridentatus by numberand L. spinosa by mass whereas in winter the mostimportant prey was Peltarion spinosulum. The temporalpattern indicates that P. bergi probably modiWes itsdiet in response to prey abundance.