Rev. biol. mar. oceanogr. 50(2): 221-234

Artícle

Feeding ecology of the planehead filefish Stephanolepis hispidus (Pisces: Monacanthidae), in the Canary Islands area

Néstor Javier Mancera-Rodríguez¹ and José Juan Castro-Hernández²

¹Universidad Nacional de Colombia, Department of Forestry Sciences, Calle 59A No. 63-20, Bloque 20, oficina 211, Medellín, Colombia

²Universidad de Las Palmas de Gran Canaria, Department of Biology, Edf. Ciencias Básicas, Campus de Tafira, 35017, Las Palmas de Gran Canaria, Islas Canarias, España

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The feeding ecology of the planehead filefish, Stephanolepis hispidus, in waters of the Canary Islands was examined. The study was based on the stomach contents of 823 specimens, from 8.9 cm to 25.9 cm in total length (TL), caught monthly in fish traps from February 1998 to June 1999. Approximately 27.2% of the fish showed empty stomachs. This proportion varied significantly between sexes but not among size classes or the evaluated seasons. The food composition of planehead filefish was composed mainly of hydroids, amphipods, echinoids and algae. Gastropods, decapods and lamelibranchs were secondary prey. According to the observed ontogenetic shift, small-sized individuals (< 12.9 cm TL) fed primarily on small crustaceans (amphipods and hydroids), whereas large-sized specimens consumed echinoids, algae, and lamelibranchs. Hydroids and algae were more important in spring, and amphipods were more important in winter. Echinoids increased in summer and autumn. The values of Morisita’s index indicated diet overlapping between individuals of length classes smaller and larger than 12.9 cm TL (S= 0.77). Likewise, the seasonal variation in the diet overlapping was high during winter (S= 0.95) and spring (S= 0.93) but was relatively lower in autumn (S= 0.68). The results indicated that the diet of planehead filefish was characterized by a narrow range of prey items with some degree of selectivity and was composed mainly of macroinvertebrates.

Key words:  Trophic niche breadth, eastern central Atlantic, diet composition, ontogenetic changes