Feeding habits of the white-dotted skate, Bathyraja albomaculata (Chondrichthyes, Rajidae), on the Argentinean Continental Shelf.

SHIMABUKURO, VALERIA M.; SCENNA, LORENA B.; BARBINI, SANTIAGO A.; FIGUEROA, DANIEL E.; DIAZ DE ASTARLOA, JUAN. M.; COUSSEAU, MARÍA B.

Saint Luis, E.E.U.U.

Congreso; Joint Meeting of Ichthyologists & Herpetologists; 2007

American Society of Ichthyologists and Herpetologists - American Elasmobranch Society

The white-dotted skate, Bathyraja albomaculata (Norman, 1937), is a medium size species in the Magellan region, from Uruguay in the Atlantic to central Chile in the Pacific. Diet composition, changes with sex and maturity status, and feeding strategy of this species were investigated in Argentinean waters (35°-55°S) through stomach contents analyses. Specimens were collected from research cruises carried out by Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP) between September 2003 and May 2005. Stomach contents were fixed in formalin 4%. Prey were counted, weighted, and identified to the lowest possible taxonomic level. Of a total of 184 stomachs examined, 95.1% contained food. All the sample sizes were sufficient for comparison, as the cumulative curves of diversity reached an asymptote. According to the Index of Relative Importance expressed as a percentage, polychaetes (67.97%) were the most important prey group in the diet of B. albomaculata followed by amphipods (23.78%) and isopods (8.13%). Cumaceans, crabs, euphausiids, teleosts, ophiuroids, hydrozoans and priapulids were not important in the diet (IRI