双齿围沙蚕胚胎及幼体发育的研究

Study on the embryonic and larval development of Perinereis aibuhitensis

2003～2004年,观察了双齿围沙蚕(Perinereis aibuhitensis)胚胎及幼体发育.结果表明,成熟卵为绿色,卵径175～228 μm,多油球;胚胎发育经历卵裂期、囊胚期、原肠期、担轮幼虫期;后担轮幼虫期胚体脱卵膜孵化;幼体从3刚节疣足幼虫开始,在3刚节疣足幼虫后期开始摄食;4刚节疣足幼虫后期纤毛轮消失,进入匍匐阶段;10刚节疣足幼虫形态与生态都与成体相似;从受精卵发育到4刚节疣足幼虫的时间在不同水温情况下变化较大,水温在25～26℃为118 h、而水温在27.5～32℃为82 h.

The embryonic and larval developments of Perinereis aibuhitensis were observed in 2003 and 2004.The result was that:the fertilized egg appeared green,its size ranged from 175 to 228 μm and had lots of oily granules.The embryonic development of Perinereis aibuhitensis could be divided into 4 stages:cleavage,blastoderm,gastrule and trochophora.The larva began from 3 setiger juvenile and began to be fed at the end of 3-setiger nectochatte;the cilia annulus vanished at the end of 4 setiger juvenile;at the same time the larva began to grovel;the 10-setiger nectochatte was similar to the fully grown worm.When the water temperature was from 25 ℃ to 26 ℃,the time from fertilized egg to 4 setiger juvenile was 118 h,but when the water temperature was from 27.5 ℃ to 32 ℃,the time was 82 h.