The observation of embryonic and larval development of Opsariichthys bidens in Luanhe River system
In order to understand the embryonic and larval development of Opsariichthys bidens(Chi-nese hooksnout carp)in Luanhe River system,a systematically observation was conducted on it.The results showed that the fertilized eggs were round and sinking,yellow or dark yellow,eggs diameter 1.2～1.4 mm,water-absorbed eggs diameter 1.4～1.6 mm.Under the condition of incubation water temperature of 19～22℃,it underwent 7 stages:blastoderm,cleavage,blastula,gastrula,neurula,organogenesis and hatching,lasting for 50 h 46 min,with total incubation accumulative temperature of 1 054.90 ℃·h.Under the condition of water temperature 22～25 ℃,the average total length of day-old larvae was(6.03±0.24)mm.The eyes were covered with melanin at the age of 2 days.The pectoral fin appeared at the age of 3 days.The swim bladder appeared at the age of 4 days,and the yolk sac was completely consumed at the age of 5 days.The total length of 17-day-old larvae was(14.55±0.40)mm,and the fins were fully developed.The growth characteristics of its early devel-opmental stage(1～～17 days old)conform with the formula:y=0.014 5x2+0.262 7x+6.044 3(R2=0.993 3).
Luanhe River basinOpsariichthys bidensembryonic developmentlarva development
万方数据
维普
