Rosa Paula Maria, de Souza Queiroz Murilo, Pelinson Rodolfo Mei, Anjos Luciano A, de Cerqueira Rossa-Feres Denise
Universidade Estadual Paulista "Júlio de Mesquita, Filho", Instituto de Biociências, Letras e Ciências Exatas, Campus de São José do Rio Preto, Brazil.
Universidade Estadual Paulista "Júlio de Mesquita Filho", Faculdade de Engenharia, Campus de Ilha Solteira, Brazil.
Int J Parasitol Parasites Wildl. 2024 Nov 26;25:101023. doi: 10.1016/j.ijppaw.2024.101023. eCollection 2024 Dec.
Parasites can impact tadpole survival in both lethal and sublethal ways. Sublethal effects include alterations in morphology and behavior, reduced competitive ability, and increased vulnerability to predation, while lethal effects result in direct mortality. These impacts can have significant consequences at both individual and population levels, especially given that amphibians host various parasites and pathogens, which may contribute to population declines. This study investigated the influence of digenetic trematodes, specifically sp. and Echinostomatidae metacercariae - larval stages found in second intermediate hosts, on the development and behavior of tadpoles. Behavioral experiments assessed tadpole activity (time and movement number), water column use, and food consumption rates using video recordings and image analysis. Swimming performance was evaluated through predation simulations, and tadpole morphology (i.e. body size and mass) was measured post-experimentally. Infections by these digenetic trematodes resulted in a notable reduction in tadpole activity. A negative correlation was observed between sp. parasite load and both tadpole activity duration and movement frequency, indicating a common response to trematode infection. This study underscores the need for further research on digenetic trematodes to determine whether these behavioral modifications represent host manipulation by the parasites, potentially optimizing their transmission to the final host.
寄生虫可以通过致死和亚致死两种方式影响蝌蚪的生存。亚致死效应包括形态和行为的改变、竞争能力的降低以及被捕食的易感性增加，而致死效应则导致直接死亡。这些影响在个体和种群层面都可能产生重大后果，特别是考虑到两栖动物携带各种寄生虫和病原体，这可能导致种群数量下降。本研究调查了复殖吸虫，特别是在第二中间宿主体内发现的特定种类吸虫和棘口科尾蚴（幼虫阶段）对蝌蚪发育和行为的影响。行为实验通过视频记录和图像分析评估蝌蚪的活动（时间和移动次数）、水柱利用情况和食物消耗率。通过捕食模拟评估游泳性能，并在实验后测量蝌蚪的形态（即体型和体重）。这些复殖吸虫的感染导致蝌蚪活动显著减少。在特定种类吸虫的寄生虫负荷与蝌蚪活动持续时间和移动频率之间观察到负相关，表明对吸虫感染有共同反应。本研究强调需要对复殖吸虫进行进一步研究，以确定这些行为改变是否代表寄生虫对宿主的操控，这可能会优化它们向终末宿主的传播。
