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Fishery and Sea ResourcesFigure 2: Specific daily growth rates in wet weight of Dicentrarchus labrax cultured insubmerged (sub) and surface (surf) cages.serum, blood samples not treated with heparin,were allowed to clot at 4°C, centrifugedat 1500g for 20 minutes and storedat -80°C until analysis.2.2 Analytical assaysHaematological and biochemical parameters:all assays were carried out using commercialdiagnostic kits.Serum cortisol concentration was determinedby a enzyme-linked (ELISA) immunoassaykit (Alpha Diagnostic International,USA).Serum glucose and total protein levelswere determined by kits respectively basedon the colorimetric Glucose Oxidase-Peroxidase (GOD-POD) and chemicalbiuret-tartrate methods (Sclavo Diagnostics,Italy).Plasma lactate was assayed by a kit that utilizethe enzymatic colorimetric method ofLactate Oxidase-Peroxidase (LOD-POD)(Roche Diagnostics, Italy).Haematocrit value (% red blood cell) wasdetermined in heparinized capillary tubesafter centrifugation in a standard microhaematocritcentrifuge at 12000 g for 10minutes and comparison of the capillarytubes with a reference scale.2.3 Immunological parametersHaemolytic activity against sheep erythrocyteswere determined in serum samples,according to Caruso et al. [23].Non specific haemolytic activity (SH50)was assayed using a 2.5% suspension ofsheep red blood cells (SRBC) in phosphatebuffered saline (PBS) containing 10 mMMg 2+ and 2 mM Ca 2+ added to seriallydiluted serum in PBS-Ca-Mg buffer. Afterincubation at 22°C for 1 h, unlysed erythrocyteswere removed by centrifugationand the content of haemoglobin in the supernatantsmeasured at 540 nm [24]. TheSH50 units were obtained from the concentrationof serum giving 50% haemolysis of2152