Physiological analyses of host-finding behaviour in trematode cercariae: adaptations for transmission success
Physiological analyses of host-finding behaviour in trematode cercariae: adaptations for transmission success
复制标题
吸虫尾蚴宿主寻找行为的生理分析：传播成功的适应
作者：
W. Haas
摘要对几种主动寻找和入侵宿主的尾蚴的行为进行生理分析，发现它们的行为模式和对来自环境和宿主的非常不同的刺激的反应非常复杂。这些生理学研究的结果是，所研究的每个物种的行为模式都是惊人的个体化。对这些物种寻找宿主的行为模式进行了一些详细的分析，揭示了它们为最大限度地提高传播成功率而进行的深刻适应。这可以通过游泳时的运动模式、对重力、光线和温度等环境条件的反应、对阴影、水流湍流和化合物等宿主发出的刺激的反应，特别是与宿主接触后的反应来证明。其行为模式可解释为：（1）离开中间宿主的栖息地而扩散，并在该区域内分布，（2）通过节省能量的游泳行为、避免对不适当刺激的反应、选择有利的微生境以及可能避免捕食而长期生存;（3）通过选择宿主经常光顾的微生境和对宿主发出的特定刺激序列作出反应来发现和入侵特定的宿主类型。
SUMMARY Physiological analyses of the behaviour of several cercarial species which actively find and invade their hosts have revealed very complex sequences of behaviour patterns and responses to very different stimuli from the environment and the host. A result of these physiological studies is that the behaviour patterns of each of the species investigated are surprisingly individual. The behavioural patterns of host-finding of those species analysed in some detail reveal profound adaptations to maximize transmission success. This can be demonstrated for movement patterns during swimming, for responses to environmental conditions such as gravity, light and temperature, for responses to stimuli emanating from the host such as shadows, water turbulence and chemical compounds and especially for the responses after contact with the host. The behaviour patterns can be interpreted as adaptations to: (1) dispersal by leaving the habitat of the snail intermediate host and distribution within the area; (2) long survival by energy saving swimming behaviour, by avoiding responses to inappropriate stimuli, by selecting favourable microhabitats and probably by avoiding predation; (3) finding and invading particular host types by selecting microhabitats frequented by the hosts and responding to sequences of specific stimuli emanating from the hosts.