三疣梭子蟹活体胚胎发育的观察

STUDIES ON THE EMBRYONIC DEVELOPMENT OF PORTUNUS TRITUBERCULATUS

观察了三疣梭子蟹胚胎发育全过程，整个胚胎发育过程约需６８０小时。卵排出约５２小时后开始表面卵裂，至２５６细胞时进入囊胚期。囊胚后期，预定内胚层细胞出现，并与集中在其周围的其他细胞一起内陷，形成原肠。胚胎发育到后期，具３对附肢的卵内无节幼体与具７对附肢的卵内状幼体依次出现。复眼，心脏和色素细胞均在卵内体阶段产生。孵化前２天的胚胎离体后仍能正常发育、孵化。

We studied the embryonic development of Portunus trituberculatus. The development lasted 680 hours from spawing to hatching. The egg didn't begin to cleave untill 52 hours after spawing. The pattern of cleavage was superficial cleavage. The blastula formed when the egg blastmeres add up to 256 cells. The presumptive endoderm presented in the later stage of blastula. The gastrulation formed with the presumptive endoderm and other cells near them invaginating. The first stage of egg larva was the egg nauplius with three pair appendages. The next stage of egg larve was egg zoea with 7 pair appendages. The compound eyes, heart and pigment cells were also found in egg zoea stage. Eggs stripped from female crab 2 days before hatching can development and hatch.