Chemical cues from fish heighten visual sensitivity in larval crabs through changes in photoreceptor structure and function
Chemical cues from fish heighten visual sensitivity in larval crabs through changes in photoreceptor structure and function
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DOI：
10.1242/jeb.125229
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发表时间：
2015-11-01
影响因子：
2.8
通讯作者：
Cohen, Jonathan H.
中科院分区：
文献类型：
--
作者：
Charpentier, Corie L.;Cohen, Jonathan H.
浮游动物的一些捕食者回避策略依赖于使用光来控制水柱中的垂直位置。虽然光是这种光行为的主要线索，捕食者的化学线索或利它素增加游泳对光的反应。我们目前缺乏一个机械的理解，浮游动物如何整合视觉和化学线索介导的表型可塑性防御光行为。在海洋系统中，利它素被认为是鱼体粘液的氨基糖降解产物。在这里，我们表明，增加浓度的鱼利它素提高光介导的游泳行为的敏感性的两个幼虫蟹种（Rhithropanopeus harrisii和Hemigrapsus sanguineus）。与这些行为的结果相一致，我们报告增加视觉灵敏度在视网膜水平的幼蟹眼睛直接急性（1-3小时）利它素曝光，证明电生理的V-log I曲线和形态从更宽，更短的横纹肌。所观察到的视觉灵敏度的增加不对应于时间分辨率的下降，因为利它素暴露后，电生理反应的潜伏期实际上增加了。总的来说，这些数据表明，表型可塑性在幼蟹photobehavior实现，至少部分，通过感光器结构和功能的快速变化。
Several predator avoidance strategies in zooplankton rely on the use of light to control vertical position in the water column. Although light is the primary cue for such photobehavior, predator chemical cues or kairomones increase swimming responses to light. We currently lack a mechanistic understanding for how zooplankton integrate visual and chemical cues to mediate phenotypic plasticity in defensive photobehavior. In marine systems, kairomones are thought to be amino sugar degradation products of fish body mucus. Here, we demonstrate that increasing concentrations of fish kairomones heightened sensitivity of light-mediated swimming behavior for two larval crab species (Rhithropanopeus harrisii and Hemigrapsus sanguineus). Consistent with these behavioral results, we report increased visual sensitivity at the retinal level in larval crab eyes directly following acute (1-3 h) kairomone exposure, as evidenced electrophysiologically from V-log I curves and morphologically from wider, shorter rhabdoms. The observed increases in visual sensitivity do not correspond with a decline in temporal resolution, because latency in electrophysiological responses actually increased after kairomone exposure. Collectively, these data suggest that phenotypic plasticity in larval crab photobehavior is achieved, at least in part, through rapid changes in photoreceptor structure and function.