SEASONAL AND SPATIAL MOBILITY PATTERNS OF ROSE SHRIMP ARISTEUS-ANTENNATUS IN THE WESTERN MEDITERRANEAN - RESULTS OF A LONG-TERM STUDY

The mobility pattern of the deep-water shrimp Aristeas antennatus (Ris so, 1816) was studied off the Catalan coast (NW Mediterranean) over a 10 yr time scale. The study area comprises upper and middle slope dept hs and submarine canyons. This extended data set (1780 observations co rresponding to 845 days over 10 years) confirmed and allowed refinemen t of previous hypotheses of A. antennatus large-scale mobility pattern s. Our results show that this species follows a well-defined seasonal mobility pattern. It is more abundant on open slope areas (around 800 m depth) in late winter and spring. The larger fraction of the populat ion moves in submarine canyons in late summer and autumn, towards shal lower depths (around 5C0 m). This general pattern of population mobili ty is coupled with important sex and size segregation. Adult females a re present year-round throughout the different habitats sampled, while the abundance of males and juveniles is higher in submarine canyons i n autumn and early winter. The large-scale mobility pattern of A. ante nnatus is not common in deep-sea species. The relevance of our results is discussed in relation to the deep-water environment and the biolog ical cycle of the species.