HOST-PLANT SPECIALIZATION DECREASES PREDATION ON A MARINE AMPHIPOD - AN HERBIVORE IN PLANTS CLOTHING
HOST-PLANT SPECIALIZATION DECREASES PREDATION ON A MARINE AMPHIPOD - AN HERBIVORE IN PLANTS CLOTHING
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DOI：
10.2307/1940326
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发表时间：
1990-04-01
期刊：
影响因子：
4.8
通讯作者：
FENICAL, W
中科院分区：
文献类型：
--
作者：
HAY, ME;DUFFY, JE;FENICAL, W
我们研究了寄主-植物专化的因素选择以及植物防御化学在这一过程中可能发挥的作用。我们研究海洋生物是因为海洋生物群落比陆地群落含有更少的特殊食草动物，因此，为研究寄主-植物专门化的某些方面提供了一个简化的系统。我们的研究集中在圆环足类的异常栖息地构建和取食行为上，它是已知的唯一一种专门捕食几种近缘海藻的食草性海洋端足类动物。黑斑潜蝇生活在一个可移动的、双壳的栖息地，它用化学防御的棕藻--巴氏盘藻构建而成。化学分析表明，即使与其他Dictyota种和Dictyotaceae的其他相关属相比，即使这种藻类很稀有，假两栖动物的自然种群也是从Dictyyresi建立它们的栖息地。在实验室的选择和非选择测试中，假两栖类建立了栖息地，并选择性地消耗Dictyota物种，这些物种产生二羟基二萜类二萜，阻止珊瑚鱼的觅食。双足类动物避开了Dictyotaceae科的其他棕色海藻，包括一种Dictyota物种，它们不会产生这些捕食鱼类的威慑物质。从它们的栖息地移走的角足类动物在被呈现给捕食性鱼类时被迅速吃掉；在它们正常的栖息地的角足类动物一直被鱼拒绝。住所的防御价值似乎源于建造它的Dictyota的特定特征，因为被迫用可口的绿色海藻Ulva建造住所的角足类动物，在它们的住所暴露于捕食性鱼类时，很快就被吃掉了。藻类防御化学直接提示了栖息地的建立。当绿藻石蕊用粗菌素-A(Dictyota Bartayresi)产生的主要次生代谢物Pachydictyol-A处理时，拟两面体的栖息地建筑与Pachydictyol-A的浓度成比例增加。研究期间收集的所有数据都与捕食者逃避威慑是拟黑胸天牛选择寄主专化性的主要因素的假设相一致。对于数量有限的相对专门化的其他海洋食草动物，也可以得出类似的结论。
We investigated the factors selecting for host-plant specialization and the roles that plant defensive chemistry may play in this process. We studied marine organisms because marine communities contain fewer specialized herbivores than terrestrial communities, and therefore, provide a simplified system for investigating certain aspects of host-plant specialization. Our study focused on the unusual domicile-building and feeding behavior of the amphipod Pseudoamphithoides incurvaria, which is the only herbivorous marine amphipod known to specialize on a few closely related seaweeds. P. incurvaria lives in a portable, bivalved domicile that it constructs from the chemically defended brown alga Dictyota bartayresii. Chemical assays indicate that natural populations of Pseudamphithoides construct their domiciles from D. bartayresii even when this alga is rare compared to other Dictyota species and to other related genera in the family Dictyotaceae. In both choice and no-choice tests in the laboratory, Pseudamphithoides built domiciles from and selectively consumed species of Dictyota that produced dictyol-class diterpenes that deter feeding by reef fishes. Other brown seaweeds in the family Dictyotaceae, including a Dictyota species, that did not produce these fish-feeding deterrents were avoided by the amphipod. Amphipods removed from their domiciles were rapidly eaten when presented to predatory fish; amphipods in their normal domiciles were consistently rejected by fish. The defensive value of the domicile appeared to result from specific characteristics of the Dictyota from which it was built, since amphipods forced to build domiciles from the palatable green seaweed Ulva were rapidly eaten when these amphipods, in their domiciles, were exposed to predatory fish. Algal defensive chemistry directly cued domicile building. When the green alga Ulva was treated with pachydictyol-A (the major secondary metabolite produced by Dictyota bartayresii), domicile building by Pseudamphithoides increased in proportion to the concentration of pachydictyol-A. All data collected during this study are consistent with the hypothesis that predator escape an deterrence are primary factors selecting for host specialization by Pseudamphithoides incurvaria. Similar conclusions can be drawn for the limited number of other marine herbivores that are relatively specialized.