中华绒螯蟹溞状幼体在生态育苗池中的种群结构

 2001年4~6月对辽宁盘锦辽河三角洲地区中华绒螯蟹生态育苗试验池中的中华绒螯蟹溞状幼体的种群结构进行了研究。结果显示,Z₁~Z₅的变态率分别为(77.8±11.3)%,( 67.9±24.2)%,( 47.5±20.7)%, ( 51.1±32.9)% 和( 63.8±27.5)%; 中华绒螯蟹溞状幼体在池塘中主要集中在上风位,约占43.7%~65.6%,下风位则分布较少,为14.2%~20.1%;在垂直分布方面,Z₁~Z₄系底层>表层, Z₅则相反,表层>底层。中华绒螯蟹溞状幼体昼夜水平移动主要受风向的影响,有风时它们向上风位方向移动,无风时它们则在池塘中分布较为均匀。中华绒螯蟹溞状幼体昼夜垂直移动主要收光照的影响,白天它们主要分布在水体中下层,夜间弱光照或无光时,它们分布较均匀。

Population Structure of Chinese Mitten-handed Crab(Eriocheir sinensis) Zoea in Ecological Breeding Ponds

This paper was conducted to investigate the population structure of E. sinensis zoea in ecological breeding testing ponds in Liaohe Delta district, Panjin city, Liaoning province, in April to June 2001. The result showed that the metamorphic rates of zoea of Ⅰ, Ⅱ, Ⅲ, Ⅳ and V stages were (77.8±11.3)%,( 67.9±24.2)%,(47.5±20.7)%,(51.1±32.9)%and (63.8±27.5)% respectively. Population quantity of E. sinensis zoea in upwind zone, about 43.7%~65.6%, was more (P<0.01) than that in downwind zone, about 14.2%~20.1%. In vertical distribution, mean population density of E. sinensis zoea in surface zone was less (P<0.05) than that in bottom zone from Ⅰ to Ⅳ stage; however, population density of E. sinensis zoea of V stage in surface zone was more (P<0.05) than that in bottom zone. Wind direction was dominating factor that influenced on diel horizontal migration of E. sinensis zoea, which migrated to the upwind zone when it blew, while whose horizontal distribution was comparatively uniform in ponds when there was no wind. Illumination influenced mainly on diel vertical migration of E. sinensis zoea. By daytime E. sinensis zoea collected mainly mid-and under-layer of waters, whereas at night they were was comparative uniformity in waters.