Feeding habits of Scorpaena notata (Scorpaenidae) from eastern Adriatic Sea
The feeding habits of the small red scorpionfish, Scorpaena notata Rafinesque, 1810 from the eastern Adriatic Sea, were investigated with respect to fish size, season, and sampling location. Stomach contents of 798 specimens, of 6.0-20.5 cm total length (TL), collected by commercial bottom trawls from January to December 2013, were analysed. The percentage of empty stomachs varied significantly with season (from 36.6% maximum in winter to 14.5% in spring). Prey items belonged to four major taxonomic groups: Molluscs (Gastropoda, Bivalvia and Cephalopoda), Polychaetes, Crustaceans (Stomatopoda, Decapoda Natantia, Decapoda Reptantia, Mysidacea, Isopoda and Amphipoda), Teleosteans and Algae remains. Reptantia decapods were the most important prey (%IRI = 72) followed by Natantia decapods (%IRI = 18) while the other prey groups were only occasionally ingested. The small red scorpionfish is thus a crustacean feeder, preying mainly on decapods. Fish size was the most important factor influencing diet composition. Small individuals (< 11 cm TL) fed primarily on small crustaceans (amphipods, mysids and isopods), whereas large-sized specimens consumed larger prey, such as decapods (reptant and natant) and teleosts. Diet composition showed little seasonal variation; reptant decapods were the most important prey in all seasons. There was high dietary similarity between sampling locations.