珠江斑鱯的早期胚胎发育观察

Observation on Embryonic Development of Mystus guttatus in Pearl River

观察了珠江斑鳠3批次受精卵的胚胎发育,描述及记录了胚胎发育各期的形态特征及所需时间。斑鳠的成熟卵子呈圆形,黄色,卵子直径为3.1-3.8 mm,吸水后最大卵径为4.0-4.2 mm,受精卵黏性很小。珠江斑鳠胚胎发育与其他硬骨鱼类基本相似,属于盘状卵裂。在水温（27.5±0.5）℃时,受精后约1 h 10 min进入胚盘形成期,受精2 h 15 min后进入卵裂期,受精后7 h 50 min,进入囊胚期,再经约13 h 45 min进入原肠期,受精后21 h15 min,胚孔封闭,当受精39 h 5 min后,心脏开始出现搏动,受精后55 h,仔鱼开始孵出。

The embryonic development of Mystus guttatus by artificial propagation has been studled. The developmental characters of embryos at each stage has been observed and recorded for three times. The ripe egg of Mystus guttatus was spherical and yellow color, its diameter was from 3.1 mm to 3.8 mm and it would be from 4. 0 to 4.2 mm when absorbed water. The fertil- ized eggs had a little glutinosity. The embryonic development of Mystus guttatus was similar to other fish. The fertilized eggs belonged to discoidal cleavage. When water temperature was （27.5 ±0.5）℃, the blastodisc formed at 1 h 10 min after fertilization, cleavage began at 2 h 15 min and blastula stage appeared at 7 h 50 min, gastrula stage at 13 h 45 min. Blastopore closed at 21 h 15 min and heart began beating rhythmically at 39h5min. Some embryos began to break the membrane and came out at 55 hours after fertilization.