اثر وزن و طول مولدين ماهي شيربت (Barbus grypus) روي توليد و رشد بچه ماهي تا مرحله انگشت قد

Effects of weight and length of Barbus grypus broodstock on fingerlings production and growth

The effects of weight and length of Barbus grypus broodstock on fingerlings reproductive characteristics and growth were investigated. We chose three female treatments including weight and length groups (1) 2212.5±479g, 62.68±6.7cm, (2) 4518±780g, 79.12±4.36cm and (3) 7712.5±1171g, 92.62±3.13cm. The same male broodstock were used for all the treatments with the weight and length size of 1400±100g, 54.62±7.35cm. Female broodstock were injected 3mg/kg PG hormone two times at an interval of 10 hours. Males were injected 2mg/kg once at the time females received their second injection. Larvae and fingerling survival rate and growth indices (special growth coefficient, condition factor) up to the fingerling stage were calculated for all treatments of larvae culture. Fingerling stage in ponds, O2, pH, temperature, transparency, nitrate, and phosphate were measured and no significant difference was observed (P>0.05) among the ponds. The special growth rate, condition factor, and fingerling survival of the treatments showed no significant differences (P>0.05). However, our results indicated that larvae survival rate had significant differences between treatment 2 and other treatments (P<0.05). These indices increase in broodstock weight up to treatment 2 (4518±780g, 79.12±4.36cm) and after that it will be lowered. We conclude that the treatment 2 broodstock are ideal for fingerling survival and enhancement of growth and condition factors.