Studies on the Histology of Early Embryonic Development of Portunus trituberculatus

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.