Diet composition of red bandfish, Cepola macrophthalma (Actinopterygii: Perciformes: Cepolidae), from the Aegean Sea of Turkey

Abstract

Background. The red bandfi sh, Cepola macrophthalma (Linnaeus, 1758), is a benthic fi sh usually not exceeding 450 cm in length. It occurs in the eastern Atlantic from the British Isles to the north of Senegal and is also common throughout the Mediterranean Sea. The red bandfi sh has no commercial value and is often represented in the discarded catch. The knowledge of the feeding ecology, of non-commercial as well as commercial species, is essential for implementing a multispecies approach to fi shery management. Studies on red bandfi sh feeding biology have been rather scarce and the majority of them lacked taxonomical approach. The presently reported study constitutes the fi rst report on the diet of Cepola macrophthalma from two bays on the Turkish coast. Material and methods. The study was based on the specimens of Cepola macrophthalma collected in İzmir Bay and Sığacık Bay from May 2005 to June 2006. The following basic parameters were calculated, based on the data collected during the analysis of red bandfi sh diet: relative number of food items in the gut content, frequency of occurrence, and relative weight of total gut content. Principal food items were determined using the index of relative importance (%IRI). The differences in the diet composition were tested for length groups and seasons by using the Bray-Curtis similarity index for both areas studied. Results. A total of 380 stomachs were examined in two bays. According to the analyses a total of 18 different prey species belonging to nine major systematic groups were found, i.e., Anthomedusae, Siphonophora, Polychaeta, Crustacea, Mollusca, Chaetognatha, Appendicularia, Thaliacea, and Actinopterygii. Concerning overall diet composition, crustaceans (especially copepods) were the most important prey in terms of %IRI, %N, %F, and %W in all seasons. In this study, a total of 80 taxa were found and identifi ed. According to the Bray-Curtis similarity index, the diet of the red bandfi sh was similar within all seasons for both areas. Conclusion. Stomach content analysis of red bandfi sh showed that it is a zooplanktophagous species. In addition to bottom species it feeds also on pelagic organisms. This fact indicates ontogenetically based food preferences of the species.