北方山溪鲵精巢显微结构的年周期变化

2001、2003年1～12月自秦岭北坡的溪流中，共采集北方山溪鲵(Batrachuperus tibetanus)38尾(体重27～38g)做精巢切片，在光镜下观察精巢显微结构的年周期变化。结果表明：北方山溪鲵为非连续型精子发生，精原细胞增生有两个高峰期，分别在9～11月和翌年的3～5月，初级精母细胞的成熟分裂期在6月末至7月，精子形成期在7月末至8月。每个精巢小叶可明显地分为深层的非成熟区和浅层的成熟区。非成熟区为精原细胞的贮存区，可增殖并延伸为增殖区。增殖区再发育为成熟区，为精子形成和存储的区域。在精子排出后，成熟区转变为排空区，后者被新的增殖区更替。北方山溪鲵精巢所有小叶同步发育，无精子成熟波。

Annual Cycle of Testicular Microstructures in Stream Salamanders (Batrachuperus tibetanus)

Testicular microstructure was investigated in 38 stream salamanders (Batrachuperus tibetanus) collected at the north slope of Qinling Mountain from Jan.to Dec.of 2001 and 2003.The results showed that spermatogenesis in this species followed an annual cycle,was the discontinuous type.Proliferation of spermatogonia was divided into two stages,one was from Sep.to Nov.,and the other was from Apr.to May next year.Meiosis occurs in late Jun.-Jul.,and the spermiogenesis began late Jul.and spermatozoa were present in Aug.Each lobule was distinguished from the immature region and mature region.The immature region served as a reservoir of spermatogonia,which can mitose into a proliferative region.The proliferative region transformed into the mature region,which served as the spermiogenesis site and store sperm.After spermiation,the mature region changed into the evacuated region,which was substituted by the proliferative region progressively.Spermatogenic progress was synchronized in all testicular lobules,and no maturational wave was discernible in the testis.