Infection dynamics of Cichlidogyrus tilapiae and C. sclerosus (Monogenea, Ancyrocephalinae) in Nile tilapia (Oreochromis niloticus L.) from Uganda
Infection dynamics of Cichlidogyrus tilapiae and C. sclerosus (Monogenea, Ancyrocephalinae) in Nile tilapia (Oreochromis niloticus L.) from Uganda
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DOI：
10.1017/s0022149x11000411
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发表时间：
2012-09-01
影响因子：
1.6
通讯作者：
Schiemer, F.
中科院分区：
文献类型：
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作者：
Akoll, P.;Fioravanti, M. L.;Schiemer, F.
于2008年1~11月对尼罗罗非鱼(Oreochromis Niloticus)的栖息地类型(水库、溪流、池塘和网箱)、寄主性别、大小和季节的感染动态进行了测定。在研究期间，650条被检查的鱼中有45.2%感染了Cichlidogyus spp。感染宿主平均每条鱼有8.6+/-3.4个寄生虫。在不同的栖息地类型中，受感染鱼类的比例在统计上没有差异。相比之下，来自不同栖息地类型的受感染鱼类上记录的寄生虫数量差异很大。寄生在水库鱼类中的寄生虫数量最多，在溪流寄主中最低。在性别方面，雌性尼罗罗非鱼比雄性和性未分化的鱼类感染更多，携带的寄生虫数量也更多。降雨量与月寄生虫感染率呈弱负相关。然而，除池塘外，枯水期的寄生虫数量和感染宿主的比例均高于丰水期。这项研究的结果表明，由于与栖息地改变和性别有关的鱼类行为的变化而导致的不同暴露可能是采样地点之间感染差异的原因。同时，降雨和与之相关的水文事件是调节热带水环境中单殖吸虫感染的重要因素。Cichlidogyus spp.的持续存在在鱼类中发现寄生虫，提供了可能爆发寄生虫的证据，表明生物安全措施的应用对集约化养鱼的成功至关重要。
The infection dynamics of the gill monogeneans Cichlidogyrus tilapiae and C. sclerosus on Oreochromis niloticus with respect to habitat type (reservoir, stream, ponds and cages), host sex, size and seasons was determined between January and November 2008. During the study period, 45.2% of the 650 fish examined were infected with Cichlidogyrus spp. The infected hosts harboured an average of 8.6 +/- 3.4 parasites/fish. Across habitat types, the proportion of infected fish was not statistically different. In contrast, the number of parasites recorded on infected fish from different habitat types differed significantly. The highest parasite number was recorded in reservoir-dwelling fish and lowest in stream-dwelling hosts. Concerning sex, more female O. niloticus were infected and harboured a high number of parasites than male and sexually undifferentiated fish. A weak negative relationship was found between rainfall and monthly parasite infections. However, a higher number of parasites and proportion of infected hosts were found during dry than in wet seasons, except in ponds. Results of this study show that differential exposure due to changes in fish behaviour associated with habitat modification and sex may account for the infection difference across the sampled sites. Meanwhile, rainfall and the associated hydrological events are important factors regulating monogenean infections in tropical aquatic environments. The continuous presence of Cichlidogyrus spp. in fish provides evidence of possible parasite outbreaks, indicating the application of biosecurity measures as crucial for the success of intensive fish farming.