Diets of, and trophic resources exploited by, bathyal penaeoidean shrimps from the western Mediterranean

The stomach contents of 115 specimens of Aristaeomorpha folincea, 67 specimens of Parapenaeus longirostris, and 122 specimens of Solenocera membranacea were examined to establish the composition of the diets. All material was collected by bottom trawls at depths between 198 and 590 m in the Catalan Sea during 1991-93. S. membranacea and fi longirostris had highly diversified diets based mainly on benthic organisms (polychaetes, bivalves, gastropods and echinoderms). In addition, the diet of P. longirostris also included suprabenthic organisms (mainly gammarid amphipods) and a small proportion of pelagic organisms. These two penaeoidean species had high stomach fullness index values. Both trophic diversity and stomach fullness index values were lower in A. foliacea than in the other two penaeoidean species. A. foliacea is a highly specialized feeder on pelagic and suprabenthic organisms (i.e. euphausiids, isopods, Plesionika martin). Thus, a disparity in the food resources exploited was recorded for the three penaeoidean species. Analysis of the diets of Mediterranean bathyal penaeoideans yielded characteristically high values of H' of around 5 or above, substantially higher than the values for other bathyal decapod species in the same region. This finding may be generally typical of penaeoidean species in other geographical regions in both the bathyal and the abyssal zones as well as in shallow waters.