开都河流域长身高原鳅胚胎发育观察

Embryonic Development of Triplophysa tenuis from Kaidu River Basin

为了探究长身高原鳅(Triplophysa tenuis)的早期生活史,2018年4月在察汗乌苏鱼类增殖站对长身高原鳅胚胎发育过程进行观察。随机挑取10~15粒受精卵,在XSP-24S生物显微镜下对胚胎发育情况进行连续观察并拍照,记录胚胎发育时序及各个时期的典型特征。结果显示,长身高原鳅成熟卵粒圆形、灰色透明、饱满有弹性、沉性,卵径(1.07±0.10)mm;遇水受精后,迅速出现黏性。水温(20±1)℃时,整个胚胎发育历时86 h 56 min,积温1826℃·h,依次经历胚盘期、卵裂期、囊胚期、原肠胚期、神经胚期、器官形成期和出膜7个连续发育阶段、34个时期。受精后10~15 min完成吸水,吸水后卵径为(1.50±0.09)mm;受精后1 h 22 min进入卵裂期;受精后7 h 40 min进入囊胚期;受精后11 h 17 min进入原肠胚期;受精后15 h 28 min进入神经胚期;受精后19 h 28 min进入器官形成期;受精后77 h 13 min进入出膜前期,受精后86 h 56 min完成出膜,长身高原鳅出膜仔鱼全长(4.81±0.17)mm。

Triplophysa tenuis,belonging to Triplophysa,Nemacheilidae,Cobitidae and Cypriniformes,is an important indigenous fish in Kaidu River.In this paper,we describe and illustrate the embryonic development of T.tenuis for the first time and compare early-stage growth characteristics with other Cobitidae species.The early-stage life history of T.tenuis was described and theoretical evidence was provided for breeding and release of native species in Kaidu River.Parental stock was collected from Kaidu River in April,2018,with the following characteristics:total length[female,(10.75±0.52)cm;male,(12.16±0.92)cm],body weight[female,(16.1-115.8)g;male,(5.2-23.8)g].The zygotes were obtained by dry fertilization and the incubation of zygotes was conducted in an incubator under controlled conditions:temperature,(20±1)℃;dissolved oxygen,>8.0 mg/L;50%water exchanged every 6 hours.Embryonic development sequences and typical characteristics of each period were observed and recorded using a XSP-24S biological microscope(eyepiece 10×18,objective lens 4/0.1).Results show that the mature eggs of T.tenuis were demersal,round,plump and elastic,with a diameter of(1.07±0.10)mm,and they quickly became glutinous after fertilization.The entire embryonic development period was 86 h 56 min at(20±1)℃and the maximum cumulative temperature was 1826℃.The embryonic development of T.tenuis can be divided into 7 stages:blastoderm,cleavage,blastula,gastrula,neurula,organ formation and larvae release from membrane.Water absorption was completed 10-15 minutes after fertilization,and the diameter of the fertilized egg was(1.50±0.09)mm after swelling;cleavage began at 1 h 22 min after fertilization and the blastocyst,gastrointestinal,neuroembryo and organogenesis stage occurred,respectively,at 7 h 40 min,11 h 17 min,15 h 28 min and 19 h 28 min after fertilization.Early-stage release from the membrane began at 77 h 13 min after fertilization and larvae were released from the membrane at 86 h 56 min.The average total length of newly hatched larvae was(4.81±0.17)mm.