Feeding habits of Chimaera monstrosa L. (Chimaeridae) in relation to its ontogenetic development on the southern Portuguese continental slope

Abstract

At the Portuguese continental slope, rabbitfish, Chimaera monstrosa, is distributed at depths greater than 200 m. The feeding strategy of this species was investigated based on the analysis of digestive tract contents from specimens captured during a bottom trawl survey held along the southern continental slope of Portugal. The diet of rabbitfish is high in diversity and with differences in composition according to predator size groups. Specimens smaller than 22 cm (pre-supracaudal fin length), which occurred in a restricted area, mainly fed on amphipods, while those with lengths between 22 and 46 cm fed on amphipods and decapods. Larger individuals (>46 cm) had a narrow diet spectrum, consuming mainly decapods. Conditioned by predator size group, significant differences in diet were observed between geographical areas and depths. This suggests that despite some degree of prey specialization according to predator size, this deep-water species is able to change its diet in accordance with the food-restricted environment that characterizes its habitat.