| Abstract:To realize artificial breeding and stock enhancement of Schizothorax biddulphi,a series of artificial reproduction tests were systematically carried out in 2020 for exploring key artificial technologies suchas spawning season, sex identification, hormone injection and artificial hatchery.The resulted showed that there were 44 spamming fish, 250 800 eggs and 149 000 fries.The results also revealed that the optimum concentration of artificial oxytocin was PG 13.47 mg/kg, DOM 15.27 mg/kg and LRH-A2 19.28 μg/kg;the main spawning season of S.biddulphi ranged from late of April to middle of May in southern Xinjiang; the egg diameters of S.biddulphiwere(1.7±0.15) mm, reaching(2.8±0.16) mm after water swelling; there wereseven stagesin theembryonic development process, whichwere embryo disc, cleavage, blastocyst, gastrula, neuroembryo, organ formation and membrane formation; under the condition of water temperature at 19-19.2 ℃, the fertilized eggs hatched for 93 h and 36 min, the total accumulated temperature was at 1 785.24 ℃·h.In addition, the total length of the hatchling was (7.19±0.15) mm, with heart beats and blood circulation; the development of the early larvae could be divided into four stages including yolk sac period, pre-bending phase, bending phase, andpost-bending phase; and after 7 d, the yolk sac could be completely absorbed.In this study, the artificial reproduction experiments were conducted to identify optimum concentration of artificial oxytocin aswellas the developmental characteristics of corresponding embryos and early larvae, thereby,further enriching the early life history data of S.iddulphi and providingessential data for resources protection. |
