Evaluation of culture potential of brook trout ( Salvelinus fontinalis Mitchill,1814 ) in freshwater and seawater environments in the Eastern Black Sea : Optimum environmental reqirements, egg production , feeding and growth characteristics

Evaluation of Culture Potential of Brook Trout, Salvelinusfontinalis Mitchill, 1814, in Freshwater and Seawater Environments in the Eastern Black Sea: Optimum Environmental Requirements, Egg Production, Feeding and Growth Characteristics In this thesis, culture potential (optimum environmental requirements, egg production, feeding and growth characteristics) of brook trout (Salvelinus fontinalis Mitchill, 1814) as a second species in rainbow trout farms in the Eastern Black Sea has been evaluated. Relative fecundity and egg size of brook trout were 2843±479 (2006-3572) eggs/kg and 4.58±0.254 (4.07-4.94) mm at age 3, respectively. Eyed, hatch and swimming periods were, 217-278, 387-448 and 616-708 day-degrees, respectively. Total mortality from egg to free swimming stage was estimated %48±23.7. Total lengths and weights of alevins at hatching and before free swimming were 12.1±0.32 and 19.0±0.96 mm, 72.5±5.58 and 98.9±6.22 mg, respectively. Mean yolk conversion efficiency (YCE) was 0.50. Mean weights at ambient (9-21°C), 16°C and 20°C temperature groups were increased from 26.63±6.02 to 56.66±15.38; 26.47±3.90 to 58.32±13.44 and 26.59+4.28 to 51.43+13.58 g, respectively, and growth rates of 20°C group was significantly lower than the others. Daily feed consumption rate was significantly higher at 16°C group, than those of other two groups. Brook trout with initial size of 37.0+6.91 g (n=80) reached 63.60±14.34 g in freshwater, 67.88±13.89 g at %o9-10, 54.35+15.89 g at %ol5-16 and 42.85±17.16 g at %o23-24. Although some kind of growth differences were observed between freshwater and %o9-10 groups, it was not significant, whereas differences among the other groups were significant. Routine and active oxygen consumption rates of brook trout were measured as 141 and 432, 221 and 628 mg02/kg/h at 16 and 20°C, respectively and differences were significantly important. Key words: Brook Trout, Salvelinusfontinalis, Egg Production, Larval Development, Growth, Temperature, Salinity, Oxygen Consumption, Feed Consumption, Eastern Black Sea