Aquaculture and Sea-Ranching, Faculty of Agricultural and Environmental Sciences, University of Rostock, Justus-von-Liebig-Weg 6, 18059 Rostock, Germany.
General and Specific Zoology, Institute of Biological Sciences, University of Rostock, Universitätsplatz 2, 18055 Rostock, Germany.
Parasitology. 2024 Mar;151(3):300-308. doi: 10.1017/S0031182024000039. Epub 2024 Jan 12.
A 30 years long data series on the infection dynamics of European eel ( L.) with the non-native invasive nematode Kuwahara, Niimi & Hagaki, 1974 is presented. Parasite burden was evaluated for 30 years in inland and coastal waters in Mecklenburg-Western Pomerania from 1991 to 2020. The total prevalence, mean intensity and damage status of the swim bladders were very high during the first decade (1991–2000), and significantly decreased in both marine and freshwater eel populations in the following decades (2001–2010, 2011–2020). The parasite intensity of eels in coastal waters was significantly lower compared with the freshwater systems (61.3% 79.5% in the first decade), indicating the vulnerability of the parasites to brackish water conditions and the fact that the life cycle of cannot be completed under high saline conditions. Eel caught in the western part of the Baltic Sea (west of Darss sill) had the lowest mean infection (51.8% in first decade) compared to the eastern part with 63.8%. Thus, besides different infection patterns caused by the environmental conditions, a temporal trend towards a reduced parasite intensity and a more balanced parasite–host relationship developed in the 30 years of interaction after the first invasion. Possible reasons and mechanisms for the observed trends in parasite–host interactions are discussed.
本文呈现了一项针对欧洲鳗（Anguilla anguilla）感染非本土入侵性线虫 Kuwahara、Niimi 和 Hagaki, 1974 的长达 30 年的数据系列。从 1991 年到 2020 年，在梅克伦堡-前波美拉尼亚的内陆和沿海水域对寄生虫负担进行了 30 年的评估。在最初的十年（1991-2000 年），游泳鳔的总流行率、平均强度和损伤状况非常高，并且在接下来的几十年（2001-2010 年、2011-2020 年）中，无论是在海洋还是淡水鳗种群中，都显著下降。与淡水系统相比，沿海水域鳗鱼的寄生虫强度明显较低（第一个十年的 61.3%至 79.5%），这表明寄生虫对咸水环境的脆弱性以及在高盐条件下不能完成生命周期的事实。在波罗的海西部（达尔斯浅滩以西）捕获的鳗鱼的平均感染率最低（第一个十年为 51.8%），而东部的感染率为 63.8%。因此，除了环境条件引起的不同感染模式外，在首次入侵后的 30 年相互作用中，寄生虫强度呈下降趋势，寄生虫与宿主的关系更加平衡。讨论了观察到的寄生虫-宿主相互作用趋势的可能原因和机制。
