School of Biosciences, Cardiff University, Cardiff, CF10 3AX, UK.
School of Natural Sciences, Bangor University, Deiniol Road, Bangor, GwyneddLL57 2UW, UK.
Parasitology. 2021 Jun;148(7):850-856. doi: 10.1017/S0031182021000445. Epub 2021 Mar 11.
Parasites display a wide range of behaviours that are frequently overlooked in favour of host responses. Understanding these behaviours can improve parasite control through a more precise application or development of new behaviour-based strategies. In aquaculture fish lice are an ongoing problem, infections reduce fishery production and control options are limited. Fish lice are distinct in their ability to survive and swim off hosts, allowing the transmission to multiple fish hosts across their lifespan. Here we assessed the off-host behaviour of Argulus foliaceus (a freshwater fish louse) and observed a diurnal rhythmical pattern in their behaviour. This pattern was lost when lice were exposed to constant darkness, indicating that the behaviour is not endogenously driven. Males were consistently active in light with reduced activity in darkness. In contrast, females were active during light and dark phases with peak activity at the start of dark periods. A. foliaceus was also strongly attracted to a light stimulus, preferring white- and blue-coloured lights over green- or red-coloured lights. Light is a strong driver of fish louse activity and could be used to trap parasites. Aquaculture light regimes could also be altered to reduce parasite attraction and activity.
寄生虫表现出广泛的行为，这些行为常常被忽视，而倾向于关注宿主的反应。了解这些行为可以通过更精确地应用或开发新的基于行为的策略来改善寄生虫控制。在水产养殖中，鱼虱是一个持续存在的问题，感染会降低渔业产量，而且控制选择有限。鱼虱在其生存和从宿主身上游泳的能力上是独特的，这使其能够在其生命周期内传播到多个鱼类宿主身上。在这里，我们评估了叶状鱼虱（一种淡水鱼虱）的离宿主行为，并观察到它们的行为存在昼夜节律模式。当虱子暴露在持续的黑暗中时，这种模式就会消失，这表明这种行为不是由内源性驱动的。雄性在光照下始终保持活跃，而在黑暗中则活动减少。相比之下，雌性在光照和黑暗阶段都很活跃，在黑暗期开始时活动达到峰值。叶状鱼虱也被强光刺激强烈吸引，更喜欢白色和蓝色的光，而不是绿色或红色的光。光强烈地驱动着鱼虱的活动，可以用来诱捕寄生虫。水产养殖的光照制度也可以改变，以减少寄生虫的吸引力和活动。
