A comparative study on the performance of two sturgeon hatcheries of Iran producing Acipenser persicus juveniles

The performance of two sturgeon hatcheries handling brood stocks were scored during the spawning season in 2002-2003. The brood fish were caught from the southern part of the Caspian Sea. In total 158 mature adults were propagated at the S. Rajaei fish farm and 269 at the S. Marjani farms. After checking the developmental stages and egg quality of the females and alter hormonal injections of fish, eggs were removed and fertilized by hatchery methods commonly used for acipenserids (Billard, 2000). Incubation temperature ranged between 17 and 22 degree C and the incubation period lasted 5to 7 days. About 55 percent of the breeders responded positively to hypophysis injections. The range of numbers of germinal vesicles (GV) of spawned fish varied from 4.4 to 9.9 in the S. Rajaei farm and from 4.7 to 11 in the S. Marjani farm. In immature breeders the value was more than 11. The optimum temperature for spawning ranged from 15.5 degree C to 18 degree C and 17-20 degree C in S. Rajaei and S. Marjani farms, respectively. The average weights of the breeders were 28.1 kg in S. Rajaei farm and 30.3 kg in S. Marjani farm. The average fork length, GV and fertilization rate that are important performance factors in breeding of acipenserid fish were 170 cm, 7.6 and 75.3% in the Rajaei farm, 159 cm, 7.9 and 64.5% in the Marjani farm, respectively. The performance as identified by these fctors was considered to be significantly different between the two hatcheries (P