Observation on embryonic and larval development of Schizothorax pseudaksaiensis Herzenstein

In May 2010,the fertilized eggs of Schizothorax pseudaksaiensis Herzenstein were obtained through artificial propagation and artificial insemination techniques,the embryonic and larval development were observed under artificial rearing conditions.The results showed that the mature eggs appeared light yellow in color,the egg diameter was 1.70~1.80 mm.The gap of fertilized egg approached maximum in 40 minutes after fertilization,the egg diameter was 2.90~3.10 mm.Based on morphology and typical characteristics of embryonic development,the stages of embryonic development could be divided into 6.When the water temperature was 19~21 ℃,the blastodisc forming stage occurred in 2 hours.The fries hatched out of the membrane in 125 hours 30 minutes,and the total length was 7.9 mm.The swim bladder formation occurred in 222 hours later,and the larva can swim horizontally.The analysis suggested that there was a certain degree of differences in the characteristics of embryonic development between S.pseudaksaiensis Herzenstein and the other fishes of Schizothoracinae.