Spawning period and first maturity size of deep water rose shrimp (Parapenaeus longirostris) in the Aegean Sea

Parapenaeus longirostris is one of the most important commercial crustaceans for the trawl fleet in the Aegean Sea. Spawning period and size at first sexual maturity of female P. longirostris were analysed from monthly samples collected by demersal trawls in the bay of Sigacik and Kusadasi in the Aegean Sea, from May 2008 to April 2009. The presence of ripe females was found between September and April (except March). The reproductive period, based on the percentages of maturity and gonadosomatic index (GSI), ranged throughout the year, reaching its peak two times; first peak occurred in autumn (September to November) and the second in spring (March to April). The minimum female size at maturity (carapace length) was 13.7 mm, and 50% of the female population was mature at about 24.6 mm carapace length at first maturity.