To identify a simple tool for quick evaluation of quality of endangered Caspian brown trout, Salmo trutta caspius eggs, the changes of pH (both in ovarian fluid and fertilization water), turbidity (both in ovarian fluid and fertilization water), fertilization and eyeing rates were investigated in ovarian fluid samples containing perfect eggs as well as different concentrations of broken eggs. The pH of ovarian fluid and water as well as fertilization and eyeing rates decreased significantly (P<0.05) with increasing of broken eggs in ovarian fluid. In contrast, the turbidity of ovarian fluid and water as well as mortality rate of eggs increased significantly (P<0.05) with increasing of broken eggs in ovarian fluid. Also, significant correlations (P<0.01) were found between measured parameters as follow: pH of ovarian fluid vs. pH of water and fertilization and eyeing rates; turbidity of ovarian fluid vs. turbidity of water; turbidity of ovarian fluid and water vs. fertilization and eyeing rates. Our results conclude that pH and turbidity of ovarian fluid and water effectively influence on efficiency of artificial propagation. Therefore, these could be used as two simple tools for quick evaluation of quality of Caspian brown trout eggs during artificial reproduction in the hatchery.

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A feeding trial was conducted to evaluate the effects of partial fish oil replacement with vegetable oils at two levels of dietary lipid on growth performance and muscle lipid quality of Indian white shrimp Fenneropenaeus indicus. Final weight of shrimp fed control diet (100% fish oil) was higher than that of shrimp fed the other diets. Partial replacement of fish oil with vegetable oils resulted in reduced levels of eicosapentaenoic acid and docosahexaenoic acid in shrimp muscle tissue. Increasing the dietary lipid level had an effect on lipid content of shrimp, by increasing lipid deposition in muscle tissue, but without a significant effect on growth. Concentrations of cholesterol in shrimp 6 Corresponding muscle were not significantly affected by dietary lipid source and level (P > 0.05). Shrimp fed diets with 14% lipid had significantly higher concentration of malonaldehyde (thiobarbituric acid reactive substances) in muscle tissue than shrimp fed diets with 9.5% lipid. Vitamin E concentration in muscle of shrimp fed 100% fish oil was significantly (P < 0.05) affected by dietary lipid level. PRACTICAL APPLICATIONSThe high market value of and great demand for penaeid shrimp in the world market provide a strong stimulus for its intensive culture. The Indian white shrimp Fenneropenaeus indicus (Milen Edwards) was the most important shrimp species cultivated in Iran (due to market demand, high market value and local shrimp). It is a species with relatively slow growth potential compared to Penaeus monodon and its production is relatively low in intensive farms. It is mainly reared with commercial feed. Fish oil is an important ingredient used in commercial marine fish and shrimp feeds. The demand for fish oils in the aquafeed industry has increased steadily despite the static global production levels and may not be able to cater to the demand in the near future. Therefore, finding alternative to fish oils is one of the critical research areas in marine fish and shrimp nutrition. 406 H. OURAJI ET AL. INDIAN WHITE SHRIMP GROWTH RESPONSE AND MUSCLE LIPID