三疣梭子蟹胚胎发育早期的组织学研究

Studies on the Histology of Early Embryonic Development of Portunus trituberculatus

摘要: 对三疣梭子蟹(Portunus trituberculatus)胚胎发育早期(卵裂至原肠胚期)进行了组织学观察，结果发现：卵排至体外约52 h后开始卵裂，卵裂方式为表面卵裂，卵裂至256细胞时，胚胎发育进入囊胚期。囊胚为实囊胚，囊胚后期，16个排成倒喇叭形的预定内胚层细胞与聚集在其附近的其他细胞一起内陷形成原肠。预定内胚层细胞脱离原肠后，进行1次切向分裂，形成卵黄细胞和内胚层细胞。与此同时，胚区细胞不断分裂，产生视叶原基和胸腹原基，不久，2个胸腹原基逐渐愈合形成胸腹突。随胚胎发育，在似桥细胞带上出现大颚原基、大触角原基，随后在大触角原基与视叶原基之间的腹中线上发生口凹。在小触角原基产生后，胚胎发育进入卵内无节幼体期。

Abstract: The zygote doesnt begin to cleave until the time 52 hours after it is spawned.The pattern of cleavage is superficial cleavage.The blastula is formed when the total numbers of the blastomeres add up to 256.In the late stage of the blastula,the presumptive endoderm cells and the other cells invaginate in the yolk and form gastrulation.Mandible rudiment and the antenna rudiment form in the bridge like cells group.The stomodeum forms in the middle of the ventral plate.With the forming of the antennula,the egg nauplius stage is identified.