本地鲶鱼生物学特性及性腺显微结构初步研究

Studies on the Biological Characteristics and the Microstructures of Gonads of Local Catfish

对本地鲶鱼的形态、生活习性、食性等生物学特征进行了观察,并把它与在外形上与其相似的南方鲶进行了比较.发现本地鲶鱼生长缓慢,推断与南方鲶不属于同一种.采取石蜡切片技术观察了本地鲶鱼的性腺发育情况.实验结果表明:2月份所取的本地鲶鱼卵巢中的卵细胞大部分处于第Ⅲ、Ⅳ时相.精巢处于Ⅴ时期,其中包含次级精母细胞、精子细胞及成熟的精子,因此可以认为本地鲶鱼繁殖季节是4～6月,当年性成熟.此外,还分析了一种类似于大口鲶的鲶鱼,与本地鲶鱼相比除体形明显较大外,其卵巢中大部分卵细胞处于第Ⅱ时相,只能见少量的Ⅲ时相卵细胞.因此推断该种鲶鱼不是当年性成熟.

The external traits and other biological characteristics were observed,such as life habit,diet and so on.Compared with Silurus meridionalis Chen,whose external appearance was similar to the local catfish's,the local catfish grew slower.It was concluded that the local catfish and the Silurus meridionalis Chen belonged to different species.Then,the local catfish's gonad was also studied by the slice technology of paraffin wax,and then observed by light microscope.The results showed that most ova in the local catfish's ovary were in stage Ⅲor Ⅳ.Furthermore,most germ cells in testicle were in stage Ⅴ,including secondary spermatocyte,spermatoblast and spermatozoon.It concluded that the breeding season of local catfish was from April to June,and the maturation age was 1 year old.In addition,another catfish,which looked like Silurus meridionalis,were also studied and compared with the local catfish.The results showed that besides it grew bigger than the local catfish,most of its ova in the ovary were in stage Ⅱ.So it was indicated that this catfish's maturation age was more than 1 year old.