Continued massive invasion of Mysidae in the Rhine and Danube river systems, with first records of the order Mysidacea (Crustacea: Malacostraca: Peracarida) for Switzerland - ABSTRACT

A survey of invasive species belonging to the Mysidae in the Rhine and Danube Rivers and adjacent freshwater systems revealed that certain species have invaded the waters of many more countries than previously known. First records of Hemimysis anomala G. O. Sars, 1907 are given for Switzerland, Slovakia, Hungary, Croatia and Serbia. The same holds true for Katamysis warpachowskyi G. O. Sars, 1893 in Croatia and Serbia, and for Limnomysis benedeni Czerniavsky, 1882 in Switzerland. New or first records are also given for L. benedeni in the systems of artificial inland waterways of northern Germany, France and Serbia. L. benedeni and H. anomala are the first representatives of the order Mysidacea (or Mysida according to certain authors) in Switzerland. A single specimen of Paramysis lacustris (Czerniavsky, 1882) serves as a first record for the upper Danube in Austria. The observed spreading of L. benedeni in inland waterways of France suggests that it probably will soon arrive at the Mediterranean coast, with unknown consequences for indigenous populations of the closely related species in the genus Diamysis Czerniavsky, 1882. H. anomala, a top invader of continental waters in Europe, could become a potential threat at the ecosystem level if its invasion continues into large lakes, such as those connected with the Rhine system in Switzerland.