Recherches sur l'alimentation des crevettes bathypelagiques du talus continental du Golfe de Gascogne.

In the present study, the feeding habits of the bathypelagic shrimps Sergestes arcticus, S. robustus, Pasiphaea sivado, P. tarda, P. multidentata and Psathyrocaris infirma), occurring on the continental slope of the Bay of Biscay, were examined. It was concluded through the present observations that these shrimps use the pelagic resources from the environment. On the other hand, their spatial distribution in different layers prevents any trophic competition between them. The nature of the prey organisms is widely determined by the size, the efficiency of the catching techniques, but also by the possibility of special detection (the hypothesis of ocular detection of euphausiids by P. sivado). The absorption of sediment, during the rest hours, is supposed to help these shrimps to stay immobile and would result in a decrease of the possibilities of sonic detection by the predators feeding upon shrimps.