Genetic and developmental study of exotic androgenetic Corbicula clam invaded into Corbicula japonica fisheries grand in Tone river.

通过对日本蚬重要的渔业资源--通江河的外来蚬的分布和发育模式进行研究，评估外来蚬入侵对日本蚬的遗传和生态影响。同江流域分布有两种外来种：河锦鸡儿和小锦鸡儿。河蚬雌雄同体，幼虫在鳃中孵卵。河生隐翅虫通过雄核发育繁殖。从生殖腺组织学观察可知，草蛉雌雄异株，胎生。我们可以观察到正常发育的受精卵的精子从CP和卵母细胞从C. japonica。幼虫正常发育至少为D形面盘幼虫。这一结果表明，如果两个物种分布在同一地区，可能会发生杂交。Mt DNA分析构建的同源树显示，C.p在tone river可能来自韩国C. papyracea。淡水种河溪蟹（C.fluminea）与瘦肉蟹（C.leana）亲缘关系较近，与半咸水蟹（C. papyracea）和日本蟹（C. japonica）亲缘关系较远。

We examined the distribution and developmental mode of the exotic Corbicula species invaded into Tone river, i.e.important fisheries cite of C.japonica to estimate the negative genetic and ecological effect. Two exotic species, C.fluminea and C.parparatus were distributed in Tone river. C.fluminea was hermaphrodite and brood the larvae in the gill. C.fluminea reproduced by androgenesis. Judging from histological study on the gonad, C.papyracea was dioecious and viviparity. We can observe the normal development of the fertilized eggs from the sperm from cp and oocytes from C.japonica. The larvae were normally developed at least in to D-shaped veliger larvae. This result suggests possible hybridization can be occurring if two species were distributed in the same area. Mt DNA analysis to construct the phylogenic tree revealed that C.p in tone river might derive from Korean C.papyracea. Fresh water species C.fluminea was very closely related to C.leana, but distantly related to brackish C.papyracea and C.japonica The present study revealed that introduced clam, C.papyracea and C.fluminea may cause the genetic and ecological problems on domestic C.japonica population.