倒刺鲃胚胎发育的研究

Embryonic development in Spinibarbus denticulatus denticulatus

2001～2002年,采用连续观察法对倒刺(SpinibarbusdenticulatusdenticulatusOshima)人工授精的受精卵的发育进行观察,倒刺胚胎发育分为22个时期,成熟卵直径2.87～3.12mm,金黄色,沉性,具弱粘性。卵膜遇水后30～50s膨胀达最大,外膜径达3.35～3.55mm。在水温(25±0.5)℃条件下,受精卵历时43h45min孵化,积温1093.75℃·h。初孵仔鱼全长(8.93±0.35)mm,肌节数为12+16+14;具心跳、血液循环,无色素,活动能力弱,沉于水底。与本亚科其他鱼类的发育比较,倒刺具有下列3个特点:第二极体明显;发育过程中没有尾泡期;眼基期有较多的肌节。

The embryos were obtained by artificial induction of hormone-injecting in mature Spinibarbus denticulatus denticulatus. The embryo development of the S. d. denticulatus was observed consecutively during 2001-2002, and 22 developmental stages of the embryos were described and illustrated. The fully mature unfertilized egg is 2.87-3.12 mm in diameter, and the fertilized eggs of the fish are sinkable, slightly sticky, nearly spherical and orange-yellowish. The diameter of swollen egg with membrane is 3.35-3.55mm in water. When water temperature is (25±0.5)℃,43.75 h were needed to hatch the embryos. Newly hatched larvae have a total length of (8.93±0.23) mm, with about 12+16+14 myomeres and blood circulation; the active ability is infirm. The general procedure of embryo development in S. d. denticulatus is similar to that of Barbinae, but for the former, the second polar body is clearer. The embryonic development stage does not have tail vesicle, but has more myomere at optic rudiment stage.