Comparative study of Growth Parameters of Imported Grass Carps and Grass Carp in Khuzestan Province

This study aimed to develop the genetic traits which have been attributed to the high growth rate in Grass carp (Ctenopharyngodon idella). Grass carp larvae with assumed high growth rate imported from China and introduced to four private company (Shahid malaky propagation center- Shosh propagation center -Karron propagation center – Abzy propagation center) and governmental farms. Approximately 3200 larvae per hectare were stocked to the ponds after adaptation and quarantine period. Organic (cow dung) and inorganic fertilizers poured to the pond every two and three days, respectively. Daily weight gain (DWG), Condition factor (CF), specific growth rate (SGR), Weight/length correlation and mortality rate measured in a certain time during and after culture period. Fish were fed twice daily on days. The highest growth rate was achieved in Karron propagation center,  as the Karoon fish company had the highest  Condition factor (1.4 ± 0.33). Imported Grass carp had a faster growth rate than indigenous ones. The higher growth rate may be attributed to lower inbreeding index of imported carps. In general, the growth parameters of imported grass carp were statistically (P <0.05) greater than the growth of domestic one at the end of the breeding season. A significant correlation coefficient between length and weight indicates that the breeding population of the imported grass carp has genetic preferences to the same domestic population. It is recommended to cross the imported and domestic Carp to transfer genome of imported carp to the genetic storage of the domestic population in the next phase of the study.