Diets of deep-water pandalid shrimps on the Western Mediterranean slope

Abstract

The feeding habits of 3 deep-water species of pandalid shrimps occurring in the Catalan Sea (Western Mediterranean) were studied. All specimens were collected from 1988 to 1990 using bottom trawls at depths ranging between 380 and 1249 m. A total of 71 specimens of Plesionika edwardsi, 176 of P. martia, and 213 of P. acanthonotus were analyzed. Pandalid shrimps were active predators of macroplankton species. The diets of P. edwardsi and P. martia were quite similar and consisted pnmanly of benthopelagic eucarid crustaceans (Pasiphaea sp.. euphausiids). P. acanthonotus is smaller, and its diet was based on smaller prey (siphonophores, hyperiids, euphausiids). Seasonal changes in the diets of bathyal pandalids were important. Planktonic organisms were their main food resource, and pandalid diets corresponded with changes in the abundance of available planktonic resources in the Western Mediterranean. Thus, bathymetric &stribution and abundance of pandalid shrimps along the slope were related to the influence of the mesopelagic fauna on bathyal comrnunities, which is commonly accepted to decrease with depth. The bathyrnetnc distribution of pandalids is also discussed in relation to a possible competitive interaction for similar resources among certain pandalid species.