Fishery and Biology of Aristaeomorpha foliacea (Risso, 1827) (Crustacea: Decapoda) in the Northern Tyrrhenian Sea (Western Mediterranean)

The aim of the study was to provide information about the fishery, population size structure, breeding period and size at maturity of giant red shrimp, Aristaeomorpha foliacea, of the northern Tyrrhenian Sea, Italy.Data were collected directly at the local auction of Porto Santo Stefano, the main landing port of the study area, from 1991 to 1998 and during monthly surveys carried out during the year 1995.In Porto Santo Stefano the annual landing of red shrimps ranged between 2 and about 17 tons, corresponding to an annual average first sale income of 170200 000 Euros.The fishery activity depended on season and vessel and the monthly landings per unit effort ranged from less than 1 to 35 kg/day/boat, although the catch of a single boat could reach values up to 80 kg/day.Size composition of A. foliacea ranged from 14 to 46 mm carapace length (CL) for males and from 14 to 66 mm CL for females.Recruitment occurred mainly in spring.The overall sexratio observed (1.10:1) was significantly biased towards females.Females begin to be mature in March, reaching a peak between July and August.From October to March most females had resting gonads.Mature males were found all year round.Females with spermatophores on the thelycum were found throughout the year, the highest percentages being recorded from March to September.The average size at sexual maturity was 40.59 mm CL.The average size of maximum reproductive potential was 37.15 mm CL.