PDF(Pubmed)
Abstract：
Planktonic bacteria are an important part of aquatic ecosystems and interact with zooplankton. However, it is still unclear whether different planktonic bacteria differentially interfere with the responses of zooplankton to their predators. Here, we investigated the effects of different planktonic bacteria, which were isolated and purified from natural lakes, on the anti-predation (Rhodeus ocellatus as the predator) defense responses of Daphnia magna. Our results showed that the effects of planktonic bacteria on the induced life-history defenses of Daphnia were species-specific. Bacteria which increased (e.g., Escherichia coli, Citrobacter braakii) Daphnia body size also promoted the induced defense of body size, whereas bacteria which decreased (e.g., Pseudomonas spp.) Daphnia body size also inhibited the induced defense of body size. In addition, the same bacteria had different effects on induced defense traits. Some bacteria (e.g., E. coli) promoted the induced defense of body size but reduced the induced defense of offspring number, whereas other bacteria (e.g., Aeromonas hydrophila, Aeromonas veronas) weakened the induced defense of body size but had no significant effect on the induced defense of offspring number. Moreover, the differential effects of planktonic bacteria on Daphnia\'s induced defenses were not related to the bacterial degradation of kairomone. This study illustrated, for the first time, the species-specific effects of planktonic bacteria on predator-induced responses of Daphnia. IMPORTANCE This study is the first to reveal the differential effects of different species of planktonic bacteria on fish kairomone-induced defense traits and energy redistribution in Daphnia. Our results not only help deepen the understanding of Daphnia\'s inducible defenses in environments containing a variety of bacteria but also provide insights into the energy reallocation involved in anti-predator defenses.
摘要：
浮游细菌是水生生态系统的重要组成部分，与浮游动物相互作用。然而,目前还不清楚不同的浮游细菌是否有差异地干扰浮游动物对捕食者的反应。这里,我们研究了不同浮游细菌的影响，从天然湖泊中分离和纯化，关于大型蚤的反捕食（Rhodeusocellatus作为捕食者）防御反应。我们的结果表明，浮游细菌对水蚤诱导的生活史防御的影响是物种特异性的。增加的细菌(例如，大肠杆菌,citrobacterbraakii)Daphnia体型也促进了体型的诱导防御，而减少的细菌(例如，假单胞菌属。)水蚤体型也抑制了体型的诱导防御。此外,相同的细菌对诱导防御特性有不同的影响。一些细菌(例如，大肠杆菌)促进了体型的诱导防御，但减少了后代数量的诱导防御，而其他细菌(例如，嗜水气单胞菌,气单胞菌）削弱了对体型的诱导防御，但对后代数量的诱导防御没有显着影响。此外，浮游细菌对水蚤诱导防御的不同作用与细菌对海酮的降解无关。这项研究说明，第一次,浮游细菌对捕食者诱导的水蚤反应的物种特异性影响。重要性这项研究首次揭示了不同种类的浮游细菌对水蚤中鱼类kairomone诱导的防御特性和能量再分配的差异影响。我们的研究结果不仅有助于加深对水蚤在含有多种细菌的环境中的诱导性防御的理解，而且还提供了对反捕食者防御中涉及的能量重新分配的见解。
