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

Abstract

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.

Keywords:

• fish
• decapod
• seaweed‐associated
• gut content
• food item
• amphipods
• molluscs

Acknowledgements

We express our thanks to the National Council for Research and Technology Development – CNPq for a doctor scholarship to the first author; to the Coordinator of Postgraduate Program of Zoology, Federal University of Paraná, for laboratory facilities; to Dr Yoko Wakabara‐IO/USP (Amphipoda), Dr Osmar Domaneschi‐IB/USP (Mollusca), Dr Marco Fábio Corrêa Maia‐CEM/UFPR (Pisces) and MSc Madalena Shirata‐PUCPR (Algae) for the confirmation of identifications; to Dr Anselmo Antunes for the statistic analysis assistance, to Dr Paulo de Tarso da Cunha Chaves‐DZ/UFPR for the critical reading of the manuscript; to Dr Edinalva Oliveira, MSc Adriana Portes Santos Rickli and Luciana Bley Noronha for the field assistance. The present study is the Contribution No. 1653 of Department of Zoology, Federal University of Paraná, Brazil.