DIET COMPOSITION OF THE WHIPTAIL STINGRAY Dasyatis colarensis SANTOS, GOMES & CHARVET- ALMEIDA, 2004 (CHONDRICHTHYES: DASYATIDAE) IN THE COLARES ISLAND REGION, PARÁ, BRAZIL

Abstract

The diet of the Colares whiptail stingray, Dasyatis colarensis , was studied from 47 specimens caught off the Colares Island region, Pará (Brazil). The rays were collected in 2006 and stomach contents were analyzed qualitatively and quantitatively. Stomach repletion and item digestion levels were observed. The percentage frequency of occurrence (%F.O.), percentage by number (%N) and by weight (%W), Index of Relative Importance (IRI) and respective percentage (%IRI) were calculated for each item group. The results indicated that most stomachs (87%) were ¼ filled with food content and that most food items (59%) were highly digested. Crustaceans were the predominant food item (%IRI = 58) and included species belonging to the Portunidae (crabs), Alpheidae, Penaeidae e Palaemonidae (shrimps) families. Teleosts had an intermediate level of importance (%IRI = 42) in the diet of this species and corresponded to gobiid (Perciformes) species. Annelids and molluscs were rare food items. The results evidenced that this species feeds mainly on crustaceans, but also on fish and occasionally on other food items. The diet ofD. colarensis was similar to other Dasyatidae species.