中华绒螯蟹幼体及仔蟹阶段肝胰腺发育的组织学研究

Histological study on hepatosomatic development of larvae and juvenile Eriocheir sinensis

通过对中华绒螯蟹幼体及仔蟹进行连续采样和组织切片,系统地研究了该阶段中华绒螯蟹肝胰腺的发育情况。结果表明,中华绒螯蟹的肝胰腺前体出现于心跳期胚胎,由卵黄囊特化而来,为1对囊状结构,此阶段首次出现肝胰腺细胞(柱状上皮细胞)。胚胎孵化后,随着幼体的发育,肝胰腺由最初的1对囊状结构逐渐分叶生长。从Ⅰ期溞状幼体至Ⅴ期溞状幼体,肝胰腺分叶数量分别为4-6-8-12-12,肝胰腺细胞高度由(12.63±4.91)μm增至(44.16±13.57)μm。肝胰腺中的细胞组成也随着幼体的发育逐渐完善,Ⅱ期溞状幼体的肝胰腺中首次出现E细胞和B细胞,Ⅲ期溞状幼体肝胰腺中首次出现F细胞,而R细胞直到Ⅱ期仔蟹才首次出现。从大眼幼体到Ⅲ期仔蟹,肝胰腺细胞高度由(44.93±18.27)μm增至(56.38±5.69)μm。

The hepatosomatic development of larvae and juvenile Eriocheir sinensis were investigated by serial sampling and histological sections in this study.The results showed that:(1)The yolk sac was divided into two parts at egg ZoeaⅡstage and the hepatopancreatic cells(columnar epithelium)were appearing in the inner of yolk sac membrane,this indicated the starting formation of hepatopancreas.(2)The saccate structure of E.sinensis hepatopancreas gradually differentiated into the foliated structure after hatching,the quantity of foliated hepatopancreas were 4,6,8,12 and 12 at zoeaⅠ,Ⅱ,Ⅲ,ⅣandⅤstage respectively,and the height of hepatopancreas cell increased from(12.63±4.91)μm to(44.16±13.57)μm during this period.(3)Cell composition in hepatopancreas gradually improved with the growth of E.sinensis,the first appearance of E and B cell emerged at the zoeaⅡstage of larvae E.sinensis,and the first appearance of F and R cell respectively emerged at the zoeaⅢand juvenileⅡstage of E.sinensis.(4)The height of hepatopancreas cell increased from(44.93±18.27)μm to(56.38±5.69)μm with the growth of E.sinensis from megalopae to the juvenileⅢstage.