Lukas Juliane A Y, Jourdan Jonas, Kalinkat Gregor, Emde Sebastian, Miesen Friedrich Wilhelm, Jüngling Hannah, Cocchiararo Berardino, Bierbach David
Department of Biology and Ecology of Fishes, Leibniz Institute of Freshwater Ecology and Inland Fisheries, Mueggelseedamm 310, 12587 Berlin, Germany.
Faculty of Life Sciences, Humboldt University of Berlin, Invalidenstrasse 42, 10115 Berlin, Germany.
R Soc Open Sci. 2017 Jun 21;4(6):170160. doi: 10.1098/rsos.170160. eCollection 2017 Jun.
Thermally influenced freshwater systems provide suitable conditions for non-native species of tropical and subtropical origin to survive and form proliferating populations beyond their native ranges. In Germany, non-native convict cichlids () and tilapia ( sp.) have established populations in the Gillbach, a small stream that receives warm water discharge from a local power plant. Here, we report on the discovery of spotted tilapia () in the Gillbach, the first record of a reproducing population of this species in Europe. It has been hypothesized that sp. in the Gillbach are descendants of aquaculture escapees and our mtDNA analysis found both and maternal lineages, which are commonly used for hybrids in aquaculture. Convict cichlids and spotted tilapia were most probably introduced into the Gillbach by aquarium hobbyists. Despite their high invasiveness worldwide, we argue that all three cichlid species are unlikely to spread and persist permanently beyond the thermally influenced range of the Gillbach river system. However, convict cichlids from the Gillbach are known to host both native and non-native fish parasites and thus, non-native cichlids may constitute threats to the native fish fauna. We therefore strongly recommend continuous monitoring of the Gillbach and similar systems.
受温度影响的淡水系统为热带和亚热带原产的非本地物种提供了适宜的生存条件，使其能够在原生范围之外形成不断增殖的种群。在德国，非本地的 convict 丽鱼（）和罗非鱼（罗非鱼属）已在吉尔巴赫河建立了种群，这条小溪接收当地一家发电厂排出的温水。在此，我们报告在吉尔巴赫河中发现了斑点罗非鱼（），这是该物种在欧洲有繁殖种群的首次记录。据推测，吉尔巴赫河中的罗非鱼是水产养殖逃逸者的后代，而我们的线粒体 DNA 分析发现了罗非鱼和两种母系血统，这两种血统在水产养殖中常用于杂交品种。Convict 丽鱼和斑点罗非鱼很可能是由水族爱好者引入吉尔巴赫河的。尽管这三种丽鱼在全球范围内具有很高的入侵性，但我们认为它们都不太可能在吉尔巴赫河水系受温度影响的范围之外永久扩散和持续存在。然而，已知来自吉尔巴赫河的 convict 丽鱼携带本地和非本地鱼类寄生虫，因此，非本地丽鱼可能对本地鱼类群落构成威胁。因此，我们强烈建议对吉尔巴赫河及类似系统进行持续监测。
