First observations on diet and feeding strategy of boarfish, Capros aper (Actinopterygii: Perciformes: Caproidae), in the eastern Ionian Sea (central Mediterranean)

The presently reported study provides first and preliminary information on the feeding strategy and diet of boarfish, Capros aper (Linnaeus, 1758), in the eastern Ionian Sea (central Mediterranean). The sampling was carried out using the oceanographic RV PHILIA at the mean depth of 165 m in October 2014. A total of 95 C. aper were studied. The total length of the fish ranged from 4.1 to 10.3 cm. From the total number of stomachs examined only 2.1% were empty. The fullness index (RI) did not differ between juvenile and adult individuals. Cumulative prey curve showed that the sample sizes were adequate to describe the diet of the species. Capros aper fed mainly on Crustacea, especially Copepoda, followed by Amphipoda, Malacostraca, and Tanaidacea. Prey abundance and prey frequency values did not differ between juvenile and adult individuals. The determined feeding strategy showed that the most important prey taxon (Copepoda) had been eaten by more than half of the fish, but their contribution to the gut contents of these fishes was low, indicating a generalized feeding strategy with a high within-phenotype contribution to the niche width for this prey.