Abstract

The current geographical distribution of alien terrapins is poorly understood because these reptiles are difficult to detect in large natural water bodies, as they don’t vocalize, have cryptic coloration, and are typically not numerous in temperate climate. The present study tests the previously unconfirmed oral reports suggesting the presence of terrapins in several urban water bodies in the European part of Russia, which is outside the geographical ranges of native European terrapins. We assessed the presence of the terrapins indirectly, by using a parasitological analysis of a widespread alien fish Perccottus glenii which is numerous in shallow lentic water bodies. This fish can harbour diverse parasitic species. We detected the alien nematode Spiroxys sp. in the wall of the digestive tract of the studied fish. The life cycle of this nematode includes freshwater terrapins as the obligatory definitive host. Thus, detecting Spiroxys sp. in P. glenii indicates the presence of terrapins in three of the studied water bodies. This approach will be particularly valuable when the direct detection of alien terrapins is limited by the seasonality, weather, macrophyte densities, landscape features, or other factors. The discussed indirect method is an additional tool for confirming the presence of alien terrapins in water bodies in the European regions, where native terrapins are absent.

中文翻译：

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通过广泛分布的外来鱼类Perccottus glenii的寄生虫分析检测外来爬行动物

摘要

目前对外来水龟的地理分布知之甚少，因为这些爬行动物很难发声，具有隐蔽的颜色，并且在温带气候下通常数量不多，因此很难在大型天然水域中被发现。本研究测试了以前未经证实的口头报告，这些报告表明在俄罗斯欧洲部分的几个城市水体中都存在水龟，这不在欧洲本土水龟的地理范围内。我们通过对广泛的外来鱼类Perccottus glenii进行寄生虫学分析，间接评估了水龟的存在，该鱼类在浅透镜状水体中数量众多。这种鱼可以藏有多种寄生物。我们检测到了外来线虫螺旋体sp。在被研究鱼的消化道壁中。该线虫的生命周期包括淡水龟作为强制性最终宿主。因此，检测Spirooxys sp。在P. glenii表明龟的三所研究的水体的存在。当直接检测外来水龟受到季节，天气，大型植物密度，景观特征或其他因素的限制时，该方法将特别有价值。所讨论的间接方法是用于确认在没有天然水龟的欧洲地区水体中是否存在外来水龟的附加工具。