高浓度三聚氰胺对萼花臂尾轮虫生殖策略的影响

Effect of Melamine on the Reproductive Strategy of Rotifer Brachionus calyciflorus

以萼花臂尾轮虫(Brachionus calyciflorus)为受试动物,研究了不同浓度(400、800和1 200 mg/L)的三聚氰胺对萼花臂尾轮虫种群增长、有性生殖、个体大小和卵大小的影响。结果显示,三聚氰胺对萼花臂尾轮虫的24 h LC50值为2 627.00 mg/L。与空白对照组相比,800和1 200 mg/L的三聚氰胺显著降低了萼花臂尾轮虫种群增长率,提高了轮虫的休眠卵产量,增加了萼花臂尾轮虫的个体大小和卵大小。这表明在高浓度三聚氰胺作用下,萼花臂尾轮虫将更多的能量用于个体生长,并采取产出体积较大但数目较少的后代的生殖策略。当三聚氰胺浓度达到1 200 mg/L时,萼花臂尾轮虫种群的混交率和混交雌体数/非混交雌体数才显著上升。轮虫种群增长率随着三聚氰胺浓度的增大而减小,休眠卵产量却随之升高;混交雌体百分率、混交雌体数/非混交雌体数与三聚氰胺浓度间呈显著的曲线相关。

The effects of different concentrations （400,800 and 1200 rag/L） of melamine on population growth, sexual reproduction, body size and egg size of rotifer Brachionus calyciflorus were investigated. The results showed that the 24 h LCs0 value of melamine to B. calyciflorus was 2 627.00 mg/L. Compared with the controls, melamine at 800 and 1 200 mg/L decreased significantly the population growth rate, but increased the resting egg production,body size and egg size, indicating that the rotifers allocate more energy for body growth, and produce bigger but less offspring at higher concentrations of melamine. Melamine at 1 200 mg/L increased significantly the mictic rate and the ratio of mictic females/amictic females. With the increase of melamine concentration, the resting egg production increased, but the population growth rate decreased. The mictic rate and the ratio of mictic females/amictic females were curvilinear correlated with melamine concentration.