武昌南湖圆背角无齿蚌雌蚌繁殖特征的研究

研究了武昌南湖圆背角无齿蚌繁殖习性 ,该蚌为雌雄异体 ,雌雄性比为 1∶1 .1 61 5,各月、各龄雌雄性比与其自然性比有显著的适合性 ;1 龄性成熟 ,4～ 8月中旬为繁殖期 ,5月为繁殖高峰期 ,产卵适宜水温为 1 9.9～ 30 .8℃ ,繁殖高峰期的平均水温为 2 3℃ ;平均怀胚量约 6.8× 1 0 5,5月怀胚率最高 ,达82 .46%。卵细胞分批成熟 ,分批排放 ;育儿囊中的钩介幼虫大小 (壳长×壳宽×绞合部宽 )为 1 78μm× 1 57μm× 1 2 2 μm。

Studies on the Reproductive Characteristics of Female Anodonta woodiana pacifica (Heude) in South Lake, Wuhan

A.woodiana pacifica (Heude) is a widely distributed bival ve in Chi na and has important economic value. Investigations on the reproduction of this Anodonta are carried out in South Lake, Wuhan. The assessment can be briefly su mmarized as follows: The sex ratio of natural population is found 1∶1.1615,the s ex ratio of each age and month was in close agreement with the expected value of 1∶1.1615 by χ2test. The female and male individuals ma ture at 1+ age. The breeding season lasts from April to middle August. The breedin g peak period occurs in May. The suitable water temperature for reproduction is from 19.9 to 30.8℃, the average water temperature in the breeding peak period is 23℃ and the average number of embryo reaches about 6.8×105. The maximum emb ryo rate occurs in May, about 82.46%. We deduce that the ootids mature and disch arge in batches according to the development status of ootids in the same folli cle of gonad. The size (shell length×shell width×hinge width) of glochidiu m is about 178 μm×157 μm×122 μm.