Comparative feeding ecology of sympatric Solea solea and S-senegalensis, within the nursery areas of the Tagus estuary, Portugal

Among the stomach contents of 609 individuals of Solea solea and 1104 of S. senegalensis the main food items of S. solea were Corophium spp. and Hediste diversicolor, and of S, senegalensis were Corophium spp., H. diversicolor and Scrobicularia plana. For both species, the importance of larger prey items in the diet, namely H. diversicolor and Crangon crangon, increased with fish size. Feeding activity of S. solea and S. senegalensis increased in spring and summer. Short-term variations were particularly related to the tidal cycle and the two species fed in intertidal areas. Dietary differences between the two nursery areas reflected prey availability mainly. Although intra- and interspecific length classes overlapped in diet, potential interspecific competition was probably minimized by a differential habitat use pattern. (C) 2000 The Fisheries Society of the British Isles.