In this study, effects of Yersinia ruckeri antigens on the immune mechanisms of rainbow trout (Oncorhynchus mykiss) were examined. The weight of the 120 fish used in this study was 20-30 g. After injecting 1 mg of formalin-inactivated whole cells (FKC) and O-antigen (Ag-O) intraperitoneally, blood was taken from the caudal vein of anaesthetized fish and metabolic activity of leukocytes (Nitroblue tetrazolium (NBT) activities), phagocytic activity (PA), phagocytic index (PI), serum protein and serum total immunoglobulin (TIg) levels were determined on day 30 after the first immunization. The same procedure was conducted in the control group. In all the experimental groups, considerable increases in the immune indicators were found and significant differences detected between the control and experimental groups (p < 0.05). Metabolic activity of leukocytes decreased significantly (p < 0.05) during the following treatment with antigens compared to the control fish group.

In this study, some growth characteristics and meat yeald of 82 scaly carp (Cyprinus carpio Linnaeus, 1758) caught in Gölova Dam Lake between July 2017 and March 2018 were investigated by gender and age groups. 32.93 % of the samples were female and 67.07 % were male individuals. Female and male individuals were determined between the ages of II-V. Mean total length and weight in females were 40.99±1.07 cm and 1001.27±82.97 g; 37.27±0.41 cm and 734.34±30.69 g in males and 38.49±0.49 cm and 822.23±36.65 g were found in all individuals. For all the samples, height-weight relation W=0.0151TL 2.9743 (R 2 =0.8796) and the average condition factor was determined as 1.385±0.018. When the relationship between meat productivity and various body parts of C. carpio is examined, the average meat yields of fillet and carcass weights were 47.59±0.71 % and 59.19±0.82 % in the females and 49.80 ±0.32 % and 60.67± ±0.34 % in males and 49.07±0.34 % and 60.18±0.36 % were found in all the individuals. The average ratios of viscera, head, fin, skin and bone weights of body weight from unutilized body parts to body weight were 12.98±0.39 %, 22.32±0.23 %, 4.51±0.79 %, 8.49±0.25 % and 2.63±0.04 % respectively.