FIRST ASSESSMENT OF THE ROSE SHRIMP, PARAPENAEUS-LONGIROSTRIS (LUCAS,1846) IN THE CENTRAL MEDITERRANEAN

Between June 1989 and May 1990 a 1 year programme based on commercial samples and statistics was carried out to assess Parapenaeus longirost ris in the Sicilian Channel (Central Mediterranean), since mast trawl- fishing occurs outside the area currently covered by trawl surveys of the National Research Council Institute based in Mazara del Vallo. Fis hing takes place on three distinct grounds, where three different sub- stocks belonging to the same population could be identified based on l ength and maturity data. Length-based methods allowed calculation of a ll parameters needed to fit Beverton and Holt's (1957) and Thompson an d Bell's (1934) models, while natural mortality could be estimated by regressing area-specific total mortalities vs. area-specific targeted effort (as total fishing days) for the three sub-stocks. Based on the models some management proposals were formulated, within the limits im posed by the assumptions and the present management framework in Italy .