Untitled - CNR

Marine research at CNRFigure 1: Monthly trends of wet weight of Dicentrarchus labrax cultured in submerged(sub) and surface (surf) cages, relative to water temperature changes during farming.2 Materials and MethodsThe study was conducted from January toDecember 2008 in the Castellammare Gulf(NW-Mediterranean Sea) in four fish cages(two submerged and two surface cage, respectively).The fish cages under investigation(2000 m 3 ) were filled on January 2008with 75.000 specimens of European seabass (Dicentrarchus labrax initial weight:28.2 ± 4.3 gr), for each cage.The fish were manually fed with a commercialdiet twice a day according to the estimatedlive weight and water temperature.During the trial, fish were randomly collectedon a monthly basis, and total andstandard length and wet weight were immediatelyrecorded for each specimen, totest growth performance, by calculation ofthe daily specific growth rate (SGRW %).The relative condition factor (Kn, [22])was also calculated by using the follow relationship:Kn = W means |aL b | whereW represented our measured weights and|aL b | represented weight estimated bymeans allometric equations.2.1 Experimental design andsample collectionAt 3 samples time (February, June andSeptember), samples of fish (n=40) weretaken to investigate haematological, biochemicaland immunological parameters.Individuals were taken from the cagesand immediately anaesthetized using tricainemethanesulfonate, MS222 (0.1gl −1 ).Careful netting and handling were implementedto minimize stress. Blood sampleswere withdrawn separately from the caudalvein of each individual and then dividedinto different test tubes depending onthe parameter to be analyzed. Part of theblood collected in heparinized tubes wasused for the immediate determination ofhaematocrit value. The remaining fractionwas centrifuged and the obtained plasmawas stored at -80°C. In order to extract2151