盘丽鱼胚胎发育的研究

目的]了解盘丽鱼的胚胎发育过程。方法]对盘丽鱼胚胎发育过程进行观察,研究其胚胎发育的形态特征和发育特点。结果]盘丽鱼的成熟卵子为粘性,呈椭球形,其纵轴和横轴分别为1.02~1.14 mm和0.75~0.79 mm。盘丽鱼的胚胎发育过程包括卵裂期、囊胚期、原肠胚期、神经胚形成期、器官形成期和孵化出膜期6个时期。在水温(30±1)℃的条件下,整个胚胎发育过程约需50 h。受精卵约50 min后进入卵裂期,3 h后进入囊胚期,9.50 h后进入原肠胚期,20 h后胚孔封闭,50 h后出膜。刚出膜的仔鱼全长为4.29 mm。盘丽鱼卵裂前期和原肠胚期发育较快,而器官形成期发育相对较慢。盘丽鱼孵化总积温为(1 500±50)℃.h。结论]盘丽鱼与尼罗罗非鱼胚胎发育过程相似,说明它们具有较近的亲缘关系。

Preliminary Observation on the Embryonic Development of Symphysodon discus

Objective] The aim of the research was to get know of the embryonic development process of Symphysodon discus.Method] The embryonic development process of S.discus was observed and the morphological and developmental characteristics of its embryonic development were studied.Result] The mature ovum of S.discus was glutinous with ellipsoidal shape and its longitudinal axis and transverse axis were 1.02～1.14 mm and 0.75～0.79 mm resp.The embryonic development process included 6 stages of ovum-cleavage stage,blastula stage,gastrulae stage,neurulation stage,organogenesis stage and hatching stage.Under the water temperature conditions of(30±1) ℃,the whole embryonic development process needed about 50 h.Fertilized eggs came into the ovum-cleavage stage after about 50 min,blastula stage after 3 h and gastrulae stage after 9.50 h.Blastopore was closed after 20 h and embryos began to break the egg membrane and came out after 50 h.The body length of newly-hatched larvae was 4.29 mm.S.discus in early ovum-cleavage stage and gastrula stage grew faster and grew relatively slower in organogenesis stage.The total accumulated temperature for the hatching of S.discus was(1 500±50) ℃·h.Conclusion] The embryonic development process of S.discus was similar with that of Tilapia nilotica,which indicated that they had closergenetic relationship.