【作者】 李娅；

【导师】 吴岷；

【作者基本信息】 河北大学 ， 生态学， 2011， 硕士

【摘要】 引入非本土的植物、动物和病原体是当今全球环境最紧迫的挑战。引入种群的建立会对新生的生态系统产生不良影响,且对其他物种发挥显著的生态意义、演化和经济影响。政府机构已经通过设计和组织管理策略做出响应,旨在减少外来物种所产生的负面效应。本文利用两种外来入侵生物克氏原螯虾和大瓶螺作为捕食者和捕食者,研究非本土物种克氏原螯虾对入侵种大瓶螺的生态影响。为了验证螯虾捕食大瓶螺是否受螺体型大小的影响,因此我们以亚成体克氏原螯虾和体型不同的大瓶螺作为受试生物研究两者之间的选择性捕食与被捕食关系。试验中设置了3种等级(小,中,大)的大瓶螺幼体供螯虾选择;为了验证螯虾捕食过程中是否受GAS遇见率(Encounter Rate, ER)的影响,试验中设置了GAS生物量相同和数量相同两组试验;为证明经过学习获得捕食经验的螯虾捕食效率较无知虾有所提高,我们设置了经验虾(EPC)和无知虾(NPC)试验,通过克氏原螯虾选择性捕食试验显示螯虾对大瓶螺的种群结构有一定影响,试验结果如下:(1)亚成体的克氏原螯虾倾向于捕食小型螺。(2)在GAS生物量相同试验中,根据GAS生物量相同投入一定比例的大、中、小3种类型的螺,在GAS生物量相同的情况下,即小螺的数量远大于中型螺和大型螺时,螯虾只捕食小型螺,没有出现捕食中、大型螺的现象。在GAS数量相同的试验中,每种体型的螺数量相同,大螺和中螺的体积要远大于小螺,这也就增加了捕食者螯虾的搜寻效率。试验结果显示,在GAS数量相同的试验中,出现了螯虾捕食大型螺和中型螺的现象,说明螯虾在捕食过程中受到遇见率的影响。(3)为证明经过学习获得捕食经验的螯虾捕食效率较无知虾有所提高,我们设置了经验虾(EPC)和无知虾(NPC)试验,通过对两种虾的相对捕食率(RPR)的比较发现,RPR EPC > RPR NPC。说明捕食经验的获得可以提高捕食效率。试验结果显示螯虾倾向于捕食体型小的大瓶螺,因此,在非本土入侵初期引入其有效捕食者可以达到较为理想的防治效果。利用两种外来入侵生物作为捕食者和捕食者,不仅是出于防治目的的考虑,而且对研究两种入侵生物的捕食行为有着重要的意义。更多还原

【Abstract】 The introduction of non-native plants, animals and pathogens is currently the most seriouse environmental threat globally. The colonization of invasive species in new territory might cause notorious impact to the invaded ecosystem, so do to local species.I used two invasive species, namely the red swamp crayfish Procambarus clarkii (from Nanjing) and the golden apple snail Pomacea canaliculata (from Hainan) as the predatory-prey pair to study when this two lineages of invasive species which never encounter each other before were brought together, what will happen. To test the hypotheses that the predation will be influenced by the size of prey, or influenced by encounter rate, I designed the experience where the prey were composed of three size-rank (small-sized, middle-sized and large-sized). Two experiments respectively examined one with prey consisted of three size groups with the same biomass, another with prey consisted of three size groups with the same individual numbers. The second part of the experiments is to test the hypothesis that experience of the predator will influence its subsequent predation. The results of the present studies are,(1) Subadult crayfish have the tendency of predating GAS of small sizes.(2) In the same biomass where small-sized snails are much more than middle-sized and large-sized snails in number PC always consumed small-sized GAS. In same-snail-number experiments, encounter rate were relatively enhanced, therefore PC consumed GAS prey other than of small-sized.(3) The crayfish with the experience of GAS consumption showed a more efficient predation rate, in comparision to the crayfish without such experience.The results showed that the small size of crayfish tend to feed Golden apple snail , so in the early invasive stage introduction the non-native predator can be achieved more satisfactory effective control results. Use of the two invasive species as predator and prey, not only for the purpose of consideration of control, and the study of the predatory behavior of two invasive species has important significance.更多还原