The food preference of juvenile Ship sturgeon (Acipenser nudiventris Lovetski, 1828) in earthen ponds

The purpose of the present study was to determine the dietary organisms in the earthen ponds and the preferences of the fish in the consumption of them. Sampling for 6 weeks was carried out at 6 times in two 4 hectare ponds with 3 sample points in each pond. In order to evaluate zooplankton and benthos from the contents of the stomach, 180 juveniles were sampled. The Results demonstrated that. The highest abundance of food organisms in ponds was Copepoda and naupli with 49.58 % and the highest amount of them in the stomach contents of of juvenile sturgeon was in the case of Cladocera with 61.19% and Chironomidae with 25.27%. Ivlev's index (E) to Cladosera, Ostracoda and Chironomidae were positive. On the other hand, the value of E index for Copepoda was negative. The results of present study showed that, juveniles' sturgeon have a high tendency to feed from Cladosera, Ostracoda and Chironomidae. So that, Cladosera and Chironomidae are among the main food and Ostracoda is considered as an occasional food. When Cladosera, Ostracoda and Chironomidae biomass decreased in the ponds, sturgeon feed from Copepoda.