斑重唇鱼胚胎及早期仔鱼发育的初步观察

Morphological observation of embryonic and early larval development of Distychus maculates

为探究斑重唇鱼(Diptychus maculates)胚胎及早期仔鱼发育特征,2020年开展人工繁殖试验,观察并记录了斑重唇鱼受精卵胚胎发育及仔鱼发育过程。斑重唇鱼受精卵为亮黄色,呈卵圆形,卵径为(2.32±0.12)mm,约40 min后吸水膨胀,卵径达(3.38±0.19)mm。在水温12℃下,受精卵4 h形成胚盘,5 h 30 min进入卵裂期,22 h进入囊胚期,74 h 30 min进入原肠期,81 h进入神经胚期,105 h进入器官分化期,288 h 30 min开始破膜而出,初孵仔鱼平均全长10.33 mm。胚胎发育积温为3462 h·℃,破膜后14 d仔鱼开始平游。斑重唇鱼胚胎发育特征与其他裂腹鱼类有较大差异,显著差异为囊胚期胚体下部卵黄组织液开始有规则移动,直至神经胚期。斑重唇鱼拥有强大的耐饥饿能力,可保障斑重唇鱼苗种的成活率。

In order to explore the developmental characteristics of embryos and early larvae of Diptychus maculates,the artificial reproduction experiment of the fish was carried out in 2020.The embryonic development and larval development of 21 fertilized eggs of D.maculates were observed and recorded.The results showed that the fertilized eggs of D.maculates were bright yellow,oval in shape,with an egg diameter of(2.32±0.12)mm,and swelled to(3.38±0.19)mm after absorbing water in about 40 minutes.At water temperature of 12℃,the fertilized egg forms the blastoderm at 4 hours,enters the cleavage stage at 5 hours 30 minutes,enters the blastula stage at 22 hours,enters the gastrula stage at 74 hours 30 minutes,enters the neural embryo stage at 81 hours,and enters the organ differentiation stage at 105 hours,at 288 h 30 min began to break the membrane,and the average length of the newly hatched larvae was 10.33 mm.The accumulated temperature of embryonic development was 3462 h·℃,and the larvae began to swim flat 14 days after membrane rupture.The embryonic developmental characteristics of D.maculates are quite different from those of other Schizothoracinae.It is manifested in the regular movement of the yolk tissue fluid in the lower part of the embryo body at the blastocyst stage until the neuroblast stage.It had strong starvation tolerance,which can ensure the survival rate of the fish fry.