Abstract: To accomplish farming and stock enhancement of loach Barbatulabarbatulanuda, key artificial propagation technology including spawning season, gender discrimination, spawning induced by hormone injection, spawning behavior and artificial incubation was investigated in 55 000 pairs of loach broodstock collected during 2015—2019. It was found that 59.6 million of eggs and 18.403 million fry were produced with average fertilization rate of 56.0% and average hatching rate of 42.7%. The peak spawning season was observed in the loach from mid-March to early April in east mountain area of eastern Liaoning Province at the minimal water temperature of 8.5 ℃. The loach had egg diameter of (2.15±0.07)mm before water absorption and (2.35±0.05) mm after water absorption, with the ratio of female to male=2∶1, and effective time of 23-36 h after drug injection at the optimal water temperature of 17-22 ℃. At this temperature, the embryonic development lasted 72 h with the cumulative temperature of 66.67 ℃·d, and postlarvae begin to swim horizontally with the cumulative temperature of 126.5 ℃·d. The embryonic development of the loach was divided into blastoderm stage, cleavage stage, blastula stage, gastrula stage, neurula stage, organogenesis stage and hatching stage. The newly hatched larvae had total length of (4.9±0.8)mm and the body weight of (0.6±0.1)mg. The findings indicated that large-scale artificial propagation of wild loach B.barbatulanuda was accomplished by ecological regulation (temperature) and physiological regulation (injection of compound hormone)
2021, Vol. 36 
