Natural diet of fish and crabs associated with the phytal community of Sargassum cymosum C. Agardh, 1820 (Phaeophyta, Fucales) at Ponta das Garoupas, Bombinhas, Santa Catarina State, Brazil

摘要

The diet of fish and crabs associated with Sargassum cymosum beds was analysed at Ponta das Garoupas, Santa Catarina State, southern Brazil. They are reported to feed on phytal organisms. The relative importance of food items was established for these consumers, and the frequency of occurrence and volumetric methods were used for quantitative analysis. The analysis of 272 guts from 11 fish and two decapod species revealed that eight fish and one crab species had phytal organisms as important items in their diet. Amphipods and molluscs were the main phytal animals in the diet of these fish and the crab; notably Caprella scaura, Hyale media, Atylus minikoi, Tricolia affinis and Bittium varium. Commercially important fish, such as the grouper Epinephelus guaza, feed on these fish and crabs, showing that Sargassum beds constitute an important link between benthic autotrophic producers and several levels of consumers on rocky shore ecosystems at Ponta das Garoupas.