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A 6-month long growth trial was conducted to evaluate three commercial feeds: Skretting (Turkey), Biomar (Greece), and Arasco (Saudi Arabia) in juvenile sobaity, Sparidentex hasta. For confidentiality, these feeds were randomly given code names diets 1, 2 and 3 and trash fish was used as diet 4 (control). Protein in commercial diets ranged between 47.17 and 48.80% while trash fish had 57.40% protein (% dry basis). Sobaity juveniles (51.39±0.63 g) were stocked at the rate of 50fish/tank, each treatment with three replicates. Fish were fed twice daily at satiation level. The results showed that diet 2 (48.80% protein) resulted in significantly (P<0.05) better weight gain, specific growth rate (SGR), feed conversion ratio, protein efficiency ratio, apparent net protein utilization and energy retention compared to other diets. There were no significant (P>0.05) differences between the weight gain and SGR values of fish fed diet 1 (48.50% protein) and trash fish (57.40% protein) while diet 3 resulted in the lowest weight gain and SGR. The muscle fatty acid composition reflected the dietary fatty acids particularly eicosapentaenoic acid (EPA) and docosahexaenoic acids (DHA) and n-3/n-6 ratios which were significantly higher in fish fed diet 2. The results showed that diet 2 (48.80% protein) may be recommended for culture of sobaity in Kuwait.

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The objective of the study was to find a cost-effective feed from three commercial feeds, namely, Arasco (Saudi Arabia), Skretting (Turkey), and Biomar (Greece) for commercially producing silver black porgy (sobaity bream), in Kuwait. For confidentiality, these feeds were randomly given code names, diets 1, 2, and 3, which were known only to the investigating staffs. The trash fish (diet 4) was used as the control. The experiment was conducted for 28 wk with grow-out sobaity bream (210.0 ± 0.51 g) using a flow-through system consisting of twelve 1-m tanks. There were three replicates for each treatment. Fish were fed two times daily at satiation level. The results showed that fish fed diet 2 resulted in significantly ( > 0.05) better growth performance, feed utilization, and higher fillet eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) content compared to other diets. A comparison of fillet quality of cultured and wild sobaity bream showed no significant ( > 0.05) difference between sensory attributes, except that of 'flavor' in cooked fillets of wild sobaity bream. A simple economic analysis showed that the cost per kilogram of fish production was significantly ( > 0.05) the lowest in diet 2 (USD4.13), followed by diet 1 (USD5.70), diet 4 (USD6.33), and diet 3 (USD6.92). Thus, based on growth performance, feed utilization, cost of production, and nutritional quality of fillet, it is concluded that diet 2 may be recommended for commercial culture of sobaity bream in Kuwait. However, future research should focus on how to improve fillet quality of the cultured fish at par with wild fish by manipulating the feed formulation.

The efficacy of four chemical reagents, iodophor, formalin, hydrogen peroxide and bronopol as fish egg surface disinfectants were evaluated in bluefin sea bream (Sparidentex hasta). Fertilized eggs were counted and subjected to a static bath dip treatment in different concentrations of the above chemicals for 4 min before being incubated at 20 AE 0.5°C for 40 h. Treatment efficacy of the different disinfectants was evaluated by assessing the bactericidal activity, egg hatch percentage and survival of larvae up to 3 days post hatch. Results showed that iodophor at medium concentrations (75 and 100 ppm) was the best of all tested disinfectants in bacterial killing ability (12% reduction in the bacterial counts), egg hatching per cent (99.8% and 99.6% respectively) and larval survival up to 3 days post hatch (50.8% and 54.8% respectively). Formalin was the second best disinfectant at levels of 100 and 150 ppm. Hydrogen peroxide gave good results compared with the control while, bronopol showed discouraging results. In conclusion, iodophor appeared to be suitable for bluefin sea bream eggs disinfection with a 4 min exposure to 75-100 ppm when applied 14-16 h after egg fertilization.