GROWTH AND MORTALITY OF THE RED SHRIMP ARISTAEOMORPHA-FOLIACEA IN THESICILIAN CHANNEL (MEDITERRANEAN-SEA)

The deep water red shrimp Aristaemorpha foliacea is an important comme rcial species for the trawl fisheries in the Sicilian Channel (Central Mediterranean Sea; FAO statistical area 37.5). An assessment program was recently implemented by ITPP-CNR. Two years of seasonal research t rawl surveys were carried out on the Italian side of the Sicilian Chan nel. A time series of length-frequency distributions has been analyzed using different techniques; the results are used to estimate growth a nd mortality parameters of the stock. In females, two modal pulses can be discriminated for the juveniles while two-to-three ''years'' are v isible for the adults. Female growth can well be represented by a Von Bertalanffy function: as with other species, too, there are two possib le growth hypotheses, slower and faster; A. foliacea females appear to grow relatively fast anyhow. Female total annual mortality (Z) is est imated around 0.65, with a natural mortality (M) at 0.42, resulting in an exploitation rate (E) of 0.38. Male results appear similar to thos e of females, but the models are less well-defined and valid; male gro wth data are best fitted with a linear model.