Morphological development of embryos and larvae of Schizothorax waltoni Regan
XU Bin1, ZHU Xiangyun1, WEI Kaijin1*, XU Jin1, MA Baoshan1, WANG Ning1,2
1.Key Laboratory of Freshwater Biodiversity Conservation, Ministry of Agriculture and Rural Affairs, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan 430223, China; 2.College of Fisheries, Huazhong Agriculture University, Wuhan 430070, China
Abstract: Morphological and developmental characteristics of embryo and larva were observed in Schizothoraxwaltoni Regan under a light microscope in order to find out the characteristics and rules of early development stage of Schizothoraxwaltoni Regan. The fertilized eggs of the fish were found to be ovate in shape, yellow in color, and (2.53±0.10)mm in diameter， and not to be incubated at water temperature of over 17 ℃. The whole embryonic development was divided into 8 stages and 33 periods, including fertilized egg, blastoderm formation, cleavage, blastula, gastrula, neurula, organogenesis and hatching according to the external morphology and the embryonic development characteristics. The embryos were hatched 225 h 10 min post fertilization, at accumulative temperature of 2838.79 h·℃, and gill, mouth, pectoral fin, caudal fin, swimming bladder, intestinal tract were successively appeared around 11 days post hatching at water temperature of (13±1)℃. The yolk sac of larva was completely exhausted with a total length of (18.35±0.65)mm 23 days post hatching， and all fins of the fish as juvenile stage appeared 70 days post hatching, with the shape and colour of the body closed to adult. The early developmental characteristics of S.waltoni Regan had some adaptability to the habit environment.
2020, Vol. 35 
