Two Asian fresh water shrimp species found in a thermally polluted stream system in North Rhine-Westphalia, Germany

Werner Klotz,Friedrich Wilhelm Miesen,Sebastian Hüllen,Fabian Herder

doi:10.3391/ai.2013.8.3.09

Abstract

The river Erft and its tributary Gillbach in western Germany are thermally polluted, and harbour exotic plant and animal species introduced by aquarium hobbyists. Here, we report for the first time the occurrence of two species of fresh water shrimp, Neocaridina davidi (Bouvier, 1904) and Macrobrachium dayanum (Henderson, 1893), from these heavily modified waters. We briefly discuss their taxonomy and provide characters for distinguishing the species. Due to its dependence on warm waters, it is unlikely that M. dayanum populations will persist permanently beyond the range of the thermal pollution. In contrast, N. davidi is able to tolerate much colder temperature regimes, and might disperse further into the Rhine drainage. Known parasites of N. davidi are however rather specific, and do most likely not pose a threat to native or other introduced crustacean species.

Highlights

Exotic animal species may cause severe changes to native species assemblages and their aquatic habitats (Cox 2004), with numerous documented cases from freshwater fish to molluscs to crustaceans (e.g., Carmichael et al 1993; Gamradt and Kats 1996; Barbaresi and Gherardi 2000; Vitule et al 2009; Gozlan et al 2010)
The river Erft and its tributary Gillbach in western Germany are thermally polluted, and harbour exotic plant and animal species introduced by aquarium hobbyists
Two species of Asian freshwater shrimps were identified in the samples collected at Gillbach and Erft in 2011–2013: The small and colorful Neocaridina davidi (Bouvier, 1904), and the considerably larger “Red Clawed Prawn” Macrobrachium dayanum (Henderson, 1893)

Summary

Introduction

Exotic animal species may cause severe changes to native species assemblages and their aquatic habitats (Cox 2004), with numerous documented cases from freshwater fish to molluscs to crustaceans (e.g., Carmichael et al 1993; Gamradt and Kats 1996; Barbaresi and Gherardi 2000; Vitule et al 2009; Gozlan et al 2010). Permanent thermal pollution of temperate streams or rivers by warm waters originating from mining operations, power plants or other industries, may severely change animal communities and set the stage for the establishment of exotic species from warmer regions, as observed in natural warm springs in temperate habitats (Piazzini et al 2010). The natural headwaters of the Gillbach, as well as parts of the Erft, have been destroyed by coal surface mining; to date, the Gillbach’s major source is coolant water from Niederaußem, Germany’s second largest coal power plant. These discharges cause major thermal pollution, up to 25.5°C Miesen pers. observation); the Erft itself permanently receives additional warm waters from mining operations, and power plants, like the power station at Frimmersdorf

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Conclusion