Occurrence of non-native red cherry shrimp in European temperate waterbodies: a case study from Hungary

The international pet trade has caused numerous introductions of non-native species globally. This is also true for freshwater decapod crustaceans including the red cherry shrimp. This tiny creature has been previously found in thermally polluted waters in Europe (Germany and Poland). Here, we present its first occurrence in Hungary and in the entire Carpathian Basin. The species was sampled once per month over 1 yr, from November 2017 to November 2018 in a natural thermal pond (spa) and also in an adjoining non-thermal brook in Miskolctapolca, Hungary. Shrimps were preyed upon by adult fishes in the locality but many individuals, including ovigerous females and juveniles, were recorded within the survey continuously. The density of shrimps was positively correlated with the water temperature, despite some individuals being found in the non-thermal stream and also in winter. We consider that the population of this species in Hungary is now well-established and self-sustaining.