Investigation on the feasibility of Cultivation of Fingerling of the Roach(Rutilus rutilus caspicus ) until marketable size in the earthern pond with brakish and fresh waters

Abstract

In this study monoculture of roach (Rurilus rutilus caspicus) in freshwater and brackish water with 3 stocking densities as 10000, 15000, and 20000 specimens per hectare with 3 replications each carried out from the beginning of May till October 2001. Moreover, in order to, compare cultivation of roach in freshwater with brackish water another density of 10000 specimens per hectare with 3 replication also took place. Fingerlings from the Sijoval cultivation Center were stocked in a pond for wintering and after preparation of rearing ponds in second year were introduced to the pond according to appropriate and calculated stocking density. Fingerlings were fed by concentrated food which is given to white fish for feeding (SFK) up to 30 g in weight of fingerlings. Feeding calculation based on percentage of body weight varied from 5 to 15 % of body weight. Moreover, appetite of fish also considered for feeding the fingerlings. Average weight and length in the first year from hatching time up to the end of rearing period were 5.55±1.58 g and 8.57±1.02 cm. Results indicate that in the second year and in the different stocking density the average weight and length at the end of cultivation period with minimum treatment were 56.68±16.5 g and 16.79±1.21 cm respectively. In maximum stocking density the mean average length was 16.74±1.23 cm and mean average weight was 55.33±16.5. In order to compare cultivation of roach in freshwater with brackish water another stocking density of 10000 specimens per hectare with 3 replications also took place in this study. Fingerlings with average weight of 6.5±1.82 g and average length of 9.5±1.24 cm were introduced to the ponds. At the end of rearing period average final weight was 48.53±9.41 g with average length of 15.15±1.08 cm. Average daily growth in freshwater treatment from the minimum to the maximum stocking density was 0.22, 0.26, and 0.23 respectively. In brackish water replication the average daily growth was 0.22. FCR in the freshwater treatment from the minimum to the maximum stocking density was 4.4, 4.46, and 4.4 respectively and in brackish water it was 3.14. Average condition factor in freshwater was from 2.41 in the second treatment to 2.69 in the first treatment and 2.56 in the third treatment. The average value CF in brackish water was 1.39. Survival rate in the freshwater treatment from the minimum to the maximum stocking density was 85.41, 82.21, and 82.76 % respectively and in brackish water it was 88.73.