Benesh Daniel P, Duclos Laura M, Nickol Brent B
School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, Nebraska 68588-0118, USA.
J Parasitol. 2005 Aug;91(4):731-6. doi: 10.1645/GE-440R.1.
Many studies have shown that photic behavior of amphipods is subject to parasitic manipulation. However, all these investigations have focused on but one property of light (i.e., intensity). This study investigated the possibility that variable wavelength sensitivity, as a potentially important component of amphipod ecology, is subject to parasitic manipulation. The photic behavior of freshwater amphipods Hyalella azteca, infected with the duck acanthocephalan Corynosoma constrictum, was tested. The phototactic responses of infected and uninfected amphipods to various wavelengths in the visible spectrum were compared, and to delineate the effects of intensity and wavelength on behavior, the preferences of amphipods for environments characterized by various combinations of light intensity and wavelength were determined. Response to blue light (400-450 nm) was little affected by infection. Amphipod response to higher red region wavelengths (600-700 nm) was altered by infection. Infected amphipods were significantly less responsive to green region light (500-550 nm), which could lead to increased wandering throughout the water column, thereby facilitating increased parasite transmission through increased predation risk. This study reinforces the subtlety with which parasites can alter their host's behavior, presumably resulting in an increased probability of being transmitted from the intermediate host to a definitive host.
许多研究表明，双足类动物的趋光行为会受到寄生虫的操控。然而，所有这些研究都只关注了光的一个特性（即强度）。本研究调查了作为双足类动物生态学潜在重要组成部分的可变波长敏感性是否会受到寄生虫操控的可能性。对感染了鸭棘头虫（Corynosoma constrictum）的淡水双足类动物阿兹特克透明摇蚊（Hyalella azteca）的趋光行为进行了测试。比较了受感染和未受感染的双足类动物对可见光谱中各种波长的趋光反应，并且为了描述强度和波长对行为的影响，确定了双足类动物对以光强度和波长的各种组合为特征的环境的偏好。对蓝光（400 - 450纳米）的反应受感染的影响较小。感染会改变双足类动物对较高红色区域波长（600 - 700纳米）的反应。受感染的双足类动物对绿色区域光（500 - 550纳米）的反应明显较弱，这可能导致其在整个水柱中四处游动的次数增加，从而通过增加被捕食风险促进寄生虫传播增加。本研究强化了寄生虫改变宿主行为的微妙程度，据推测这会导致寄生虫从中间宿主传播到终宿主的概率增加。
