Feeding habits of brown ray (Raja miraletus Linnaeus, 1758) from the eastern central Adriatic Sea

Abstract

The feeding habits of brown ray Raja miraletus from the eastern central Adriatic Sea were investigated. The stomach contents of 418 specimens, total length (TL) of 13.5–40.0 cm, collected from commercial bottom trawls from January to December 2010 were analysed. The prey items identified in the stomachs belong to six major groups: Decapoda (Natantia and Reptantia), Mysidacea, Teleostei, Cephalopoda, Amphipoda and Polychaeta. Decapods were the most important prey (%IRI=88.2), whereas other prey groups were only occasionally ingested. Fish size was the most important factor affecting diet. According to the observed ontogenetic shift, small-sized individuals (<20 cm TL) fed primarily on small crustaceans (mysids and amphipods), whereas large-sized specimens consumed bigger prey, such as decapods, cephalopods and teleosts. Diet composition showed low seasonal variation: decapods were the most important ingested prey in all seasons. There was high dietary similarity between sampling locations. The percentage of empty stomachs did not differ significantly among size-classes and seasons. In terms of species composition, the diet of the brown ray was characterized by a variety of rare or less important prey. As a result, the brown ray could be considered to be a generalist predator.

Keywords:

• Adriatic Sea
• feeding habits
• Raja miraletus

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory, University of Copenhagen, Denmark

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory, University of Copenhagen, Denmark

Acknowledgements

The authors gratefully acknowledge the help of professional fisherman in collecting material for this study. In addition, we want to thank our Ministry of Science, Education and Sports for financial support.

Notes

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory, University of Copenhagen, Denmark