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Reared meagre (Argyrosomus regius) of average weight 1278 g was evaluated for its filleting yield and fillet lipid quality. Filleting yield averaged 42.2%, while very low levels of muscle fat deposits were measured (1.06%). Analysis of lipid classes revealed a high proportion of polar lipids (48.3-59.1%) and low levels of neutral fatty acids (40.9-51.7%) when compared to corresponding values of other farmed fish species. Phosphatidyl-choline (PC) was the dominant polar lipid (2.92 mg g )1 muscle), while cholesterol the most abundant neutral lipid (1.68 mg g )1 muscle). The fatty acid composition of meagre fillet generally reflects the dietary fatty acids. Among n-3 fatty acids, eicosapentaenoic (4.58%) and docohexaenoic (15.0%) were measured to be the most abundant ones, and 18:2n-6 (11.9%) was the most common n-6 fatty acid. The fatty acid profiles of polar and neutral fractions differ, with monounsaturated fatty acids being predominant in the neutral and n-3 polyunsaturates in the polar lipids. The high polar lipid contents and n-3 fatty acids and the low atherogenic and thrombogenic indexes indicate a high quality of this species' lipids.

This study aimed to investigate the e¡ect of increased zinc dietary levels on the growth performance, feed utilization, immune status and induced wound healing in European sea bass (Dicentrarchus labrax). Fish weighing 10 g were fed ¢ve diets containing organic zinc at 30,70,110 and 150 mg kg À 1 diet and one inorganic zinc source (zinc oxide) at 150 mg kg À 1 diet for a period of 12 weeks. No signi¢cant (P40.05) di¡erences were found in the growth performance parameters (¢nal weight, speci¢c growth rate), immunological indices tested (respiratory burst activity in whole blood) and the wound-healing process. Zinc accumulation in the skin, vertebrae and liver increased signi¢cantly (Po0.01) with increased dietary zinc levels but not in muscle. The highest zinc concentrations were obtained in skin tissue, followed by vertebrae, liver and muscle tissue. Using the concentration of zinc in skin as a response criterion, broken-line analysis showed that the supplementation of 148 mg organic Zn kg À 1 diet seemed to be the optimum dietary zinc supplementation level for sea bass juveniles.Data are presented as means of three replicates/treatment AE SD. Ã FCR (feed conversion ratio) 5 consumed dry feed (g)/weight gain (g).wSGR [speci¢c growth rate (% day À 1 )] 5 100 Â (ln ¢nal weight À ln initial weight)/days. Aquaculture Research, 2010, 41, e208^e216 Zinc requirements in sea bass F Eleni et al.

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The aim of this study was to evaluate the efficacy of dietary praziquantel (PZQ), a promising fish anthelminthic, against Zeuxapta seriolae, a lethal ectoparasite of greater amberjack (Seriola dumerili Risso) farmed in the Mediterranean and elsewhere. The trial was carried out in small cages (3 m3) in situ, harbouring fish (125 ± 14 g) naturally infected with Z. seriolae, at 25 ± 1 °C water temperature. Praziquantel-medicated diet (150 mg PZQ/kg fish) was delivered for three days against a control group. Measurement of both adults and oncomiracidia of Z. seriolae in sampled gill arches revealed significant differences between the tested groups (PZQ: 19.3 ± 9.8 vs. Control: 3.8 ± 6.3). Considering an estimated efficacy of 80.4% in the medicated fish, the present study indicates that oral PZQ treatments can confront Z. seriolae infections considerably in farmed greater amberjack and, perhaps, replace the commonly used hydrogen peroxidase baths.