Brood Stock Making of Crayfish (Astacus leptodactylus)

This project implemented in Aquaculture institute to goal of brood stock making bio-normative determination of crayfish (Astacus leptodactylus) in captivity condition in 2007-2009. For this purpose, 500 wild brooders caught from Aras Dam Lake and handled to Sefidroud Fisheries Research Station. After hatching of eggs, juveniles of crayfish reared in two earthen ponds. The juveniles reached to more than 15 g weight in the end of first year. Then young crayfish in three treatments inclusive 3, 5 and 7 animals per m2  with 1:1 sex ratio introduced to 9 ponds 150 m3 and fed with especial diet (35 % protein,  13 % fat and 4000 kcal/kg energy). Every treatment had 3 replicates. In period of rearing conducted biometry, physical-chemical factors measurement and gonadal histology. The end of second year, more than 50 percent of crayfish reached to maturation stage. The results showed that mean survival of animals was 86.87 and 90.44 percent in the end of second and third rearing year, respectively. The highest and lowest brooders number with pelepod eggs resulted in first treatment (58.91 percent) and third treatment (53.47 percent), respectively. Maximum juvenile crayfish produced in third treatment with 18.5 percent. Also, eggs and pelepod juveniles produced 58.73 and 15.56 percent in first and 54.35 and 14.52 percent in second year, respectively. Finally, average size of crayfish measured 90.48 g in weight as maximum and  minimum size was 206 and 48 g. Mean length of animals was 13.7 cm the end of the trial.