MOLT ACTIVITY-RELATED SPAWNING SUCCESS IN THE MEDITERRANEAN DEEP-WATER SHRIMP ARISTEUS-ANTENNATUS (DECAPODA, DENDROBRANCHIATA)

The relationship between mating, spawning and moult cycles of Aristeus antennatus (Risso, 1816) (Dendrobranchiata: Aristeidae) was analysed for 4 yr as a determinant of reproductive strategies. Field specimens were obtained from an exploited population off the Catalan coast, Spain (northwestern Mediterranean). It was found that females showed a marked reproductive seasonality while males showed potential for year-round reproductive activity. Although several layings occurred during an annual reproductive period, there was only 1 per instar. A. antennatus had an indeterminate growth pattern. Moulting activity of bath sexes was present throughout the year but increased in females during the reproductive period. In addition, during vitellogenesis the moult cycle of females was not prolonged during intermoult stages or during initial premoult stages. This finding indicates that the high moult activity of females during the seasonal reproductive cycle must be displayed in order to obtain an optimum level of fertilization. Furthermore, results suggest that during the spawning period, moulting phenomena are most closely linked to reproduction rather than to growth. Finally, it is proposed that intraspecific biotic factors rather than environmental and energetic ones appear to be a key for determining the reproductive success of A. antennatus.