疣吻沙蚕胚胎发育观察及盐度对其孵化的影响

采用显微镜观察了疣吻沙蚕(Tylorrhynchus heterochaeta)胚胎发育不同时期特征,并依据疣吻沙蚕人工孵化经验设置6个盐度梯度组(A:0,B:5,C:10,D:13,E:15,F:20),每组3个平行,研究了盐度对疣吻沙蚕受精率和孵化率的影响。结果表明,疣吻沙蚕胚胎发育可分为受精卵、卵裂期、囊胚期、原肠期、前担轮幼虫期、后担轮幼虫期、膜内三刚节疣足幼虫期和三刚节疣足幼虫期8个时期;盐度对疣吻沙蚕孵化影响显著(P0.05),C组受精率和孵化率最高,与其他组存在显著差异(P0.05)。适宜受精的盐度范围为10~13,最适孵化的盐度为10。

Observation on embryonic development of Tylorrhynchus heterochaeta and effect of salinity on their hatching

We observed the embryonic development of Tylorrhynchus heterochaeta and investigated the effect of salinity on their fertilization and hatching rate.In an artificial incubation experiment,the fertilized eggs were hatched in six groups (each group with 3 parallels) at different salinities (A:0,B:5,C:10,D:13,E:15,F:20).The results show:1) The embryonic development of T.heterochaeta could be divided into eight stages,including zygote,cleavage,blastula,gastrula,early trochophore,late trochophore,three setiger nectochaete (unhatch) and three setiger nectochaete (hatch).2) The hatching rate was significantly affected by different salinities.The highest fertilization and hatching rate were observed in Group C,significantly different from those in the other groups(P<0.05).The suitable salinity range for the fertilization was 10~13,and the optimum hatching salinity was 10.