Brood production of Barbus xanthopterus by fingerling rearing

This study has been carried out to determine the possibility of producing Gattan fish (Barbus xanthopterus) brooders in captivity condition. For this reason during in year 2004-2005, 600 specimen of Gattan in three pond and in 2008, from two local point shilat and research center, 200 specimen in two ponds were placed. The area of each pond was 1800 square meters. In the first period of rearing, total weight and total length of nearly two years old brooders reached to 989 g and 44 cm respectively. All of the fishes were male (except one case) and they had become mature. In second rearing period, 27 percent of shilat specimens and 42 percent of research center specimens were female. In 22 months old fishes, the males and females of shilat specimens reached to mean weight 716 and 658 g and mean length 382 and 365 cm respectively. Also, the male and females of research center specimens reached to mean weight was 1195 and 11064 g and mean length 443 and 425 cm respectively, when they were 22 months old. The absolute and specific growth rate in two rearing periods showed ascending trend and the 100 percent of brooders were survived. The male fishes were matured in 2 years old and the mature female fishes were not observed. The brooders response to pituitary extract in research center specimens was found to be more than shilat specimens.