长江刀鲚与池塘人工养殖刀鲚性腺发育的初步观察

Development of Gonads in Coilia nasus from the Yangtze River and Artificial Pond

2006～2008年间采集了长江刀鲚(Coilia nasus)及池塘养殖刀鲚共104尾,对其生物学指标进行了测定,并对不同月份、不同江段的刀鲚性腺发育状况进行了初步比较观察。组织切片观察显示:在江阴段长江刀鲚从4～7月份卵巢从Ⅱ期发育到Ⅳ期;同一时期(7月份)安庆段刀鲚精巢和卵巢的成熟系数略高于江阴段,但差异不大。池塘养殖雄性刀鲚在6月、9月基本处于增殖期,精小叶腔中存在一定量的精子细胞,但未见性成熟个体。对于雌性,在12月份卵巢处于Ⅱ期,而6月份卵巢能发育至Ⅳ期晚期,此时卵巢的成熟系数显著高于同年5月份江阴长江刀鲚和7月份安庆段刀鲚。综合组织切片结果认为:长江刀鲚的性腺发育成熟度可能与所处江段关系不大,而不同洄游群体的性腺发育情况可能相同;在人工池塘养殖状态下,部分刀鲚的卵巢至少能够发育到Ⅳ期晚期。

A total of 104 individuals of Coilia nasus were collected from the Yangtze River and artificial pond from 2006 to 2008. Comparative observation of the gonads development was conducted. The histological observation showed that the ovary of C. nasus from Jiangyin area of the Yangtze River transformed from phase Ⅱ to phase Ⅳ from April to July. The gonadosomatic index （GSI） of these sauries from Anqing area of the Yangtze River was higher than that from Jiangyin area at the same period （July）, while there was no statistical difference. For most of the males domesticated in artificial pond, the development of spermary was in proliferative period with large numbers of spermatids in spermatie lobule, but there was no mature individual found. The ovary of the female collected from the pond in December was in phase Ⅱ and could develop into the late phase Ⅳ in June. The GSI was significantly higher than that of the saury from Jiangyin area of the Yangtze River in May and Anqing area in July. Therefore, the sexual maturation of C. nasus from the Yangtze River isn＇t determined only by the migratory site, while the development of gonads is similar among different migratory populations at the same period. The ovary of C. nasus domesticated in artificial pond can develop into the late phase Ⅳ at least.