铜绿微囊藻和斜生栅藻的组合对拟同形溞生长生殖的影响

摘要

This paper studied the combined effects of single-cell toxic M.aeruginosa and S.obliquus on the growth and reproduction of D.similoides.The results showed D.similoides could not grow and reproduce under only M.aeruginosa as food.Time to maturation of D.similoides decreased with the increase of S.obliquus con-centrations,while body length at maturity increased.No.offspring at first reproduction,maximal population den-sity and maximal population growth rate increased with the increase of S.obliquus concentrations.Both maxi-mal population density and maximal population growth rate appeared in the 2×106 cells/mL of S.obliquus con-centration group,302.7 ind.(200mL)-1 and 0.213 d-1,respectively.D.similoides did not produce the ephippium under the low S.obliquus concentration (1 × 105cells/mL).There were more ephippia produced under the high-er S.obliquus concentrations(1×106 cells/mL),and the peak(77.3 ind.)occurred in the 1×106 cells/mL of S. obliquus concentration group.The percent of ephippia containing one and two resting eggs among total ephip-pia were obviously higher under the higher S.obliquus concentration groups (1 × 106 cells/mL and 2 × 106 cells/mL)than under the lower S.obliquus concentration groups(2×105 cells/mL and 4×105 cells/mL).It suggested that increasing S.obliquus concentrations might relive the inhibition of single-cell toxic M.aeruginosa on the growth and reproduction of D.similoides,while the ephippium production resting-egg formation of D.similoides were influenced by population density and M.aeruginosa together.%文章研究单细胞的产毒铜绿微囊藻和斜生栅藻的组合对拟同形溞生长生殖的影响.结果表明：拟同形溞不能在纯铜绿微囊藻下生长生殖.随着斜生栅藻浓度的升高，拟同形溞的首次怀卵时间逐渐减少，而成熟体长逐渐增大.拟同形溞的首次产幼溞数、最大种群密度及最大种群增长率随着斜生栅藻浓度的增大而增大.最大种群密度和最大种群增长率均出现在2×106 cells/mL的斜生栅藻浓度组，分别为302.7 ind.（200 mL）-1和0.213 d-1.在低的斜生栅藻浓度（1×105 cells/mL）下，拟同形溞不产生卵鞍.在2×105～2×106 cells/mL的斜生栅藻浓度下，拟同形溞产出较多的卵鞍，最大值（77.3 ind.）出现在1×106 cells/mL的斜生栅藻浓度组.在较高的斜生栅藻浓度（1×106 cells/mL和2×106 cells/mL）下，含休眠卵的卵鞍数占总休眠卵数的比例明显高于较低的斜生栅藻浓度组（2×105 cells/mL和4×105 cells/mL）.研究暗示，斜生栅藻浓度的增大可以减缓产毒单细胞铜绿微囊藻对拟同形溞的生长生殖的抑制作用，而卵鞍的产生和休眠卵的形成受其种群密度和铜绿微囊藻的共同影响.