GROWTH AND REPRODUCTIVE ECOLOGY OF PALAEMON ADSPERSUS (DECAPODA, PALAEMONIDAE) IN THE WESTERN MEDITERRANEAN

Aspects of growth and reproductive cycle of the prawn Palaemon adspers us were studied in Alfacs Bay (Ebro delta, western Mediterranean). Thi s species shows a marked sexual size dimorphism. Sexual differences re lated to length-weight were noted. The sex-ratio observed was signific antly biased towards females in the study area. Cohort analysis of the size-frequency distributions suggests the occurrence of a main recrui tment period in the study area during August and September. The estima ted von Bertalanffy growth parameters suggest rapid growth for both se xes. Ovigerous females were recorded between January and September. Th ose carrying eggs about to hatch appeared from March. Some of the earl y specimens appearing in the benthic population in summer (yearling in dividuals) had already spawned at the end of the reproductive period, together with prawns from the previous generation (wintering individua ls).