同形溞(Daphnia similis)对幽蚊幼虫反捕食策略的模拟研究

Simulated research on anti-predation reaction of Daphnia similis to Chaoborus larvae

枝角类溞会由于捕食者的存在而发生形态、行为、生活史等的变化.通过为期10 d对太湖春、夏季优势种同形溞(Daphnia similis)在有幽蚊幼虫(CL)、无幽蚊幼虫(CK)及培养过幽蚊幼虫的过滤水(FL)3个环境水平的模拟实验,发现同形溞在有幽蚊幼虫和培养过幽蚊幼虫的过滤水处理下平均体长、累积产仔数及平均产仔数均显著大于无幽蚊幼虫组,表明幽蚊幼虫释放的信息素能改变同形溞的体长、产仔数等生活史参数,这种改变会降低同形溞被捕食的风险.说明在自然环境下,幽蚊幼虫等无脊椎捕食者能通过直接捕食和信息素的间接作用共同影响枝角类种群.

Daphnia exhibits diverse morphological, behavioral and life-history responses to the kairomones of predators. A 10-day simulated experiment was conducted on anti-predation reaction of Daphnia similis, a dominant species in Lake Taihu, to inverte- brate predator Chaoboru.~ larvae. The experiment had three treatments： the presence of Chaoborus larvae （ CL）, control without Chaoborus larvae or filtered water （CK） and no Chaoborus larvae but with the filtered water that had cultured Chaoborus larvae the day before （FL）. The results showed that the average body length, average number of offspring and cumulative number of offspring of D. similis in the CL and FL treatments were significantly higher than those in the CK treatment, which suggested that the release of kairomones from Chaoborus larvae can alter the life history traits of D. similis. These alterations can reduce the predation risk of D. similis. Our results indicate that invertebrate predator can affect the cladoceran population through both direct predation and re- lease of the kairomones in the field.