Distribution of Decapoda in Hungary and the impacts of the invasive red swamp crayfish (Procambarus clarkii, Girard 1852) to the native ecosystem

Abstract

The aim of our studies to summarise the current status of the Decapods species in Hungary and presented the effect of the red swamp crayfish (Procambarus clarkii ) to the species composition in a tributary stream of the River Danube. During our field surveys the crayfishes were collected by electrofishing and different types of traps in several water habitats in whole territory of Hungary. Currently, three indigenous crayfish species occur in Hungary. The narrow-clawed crayfish (Pontastacus leptodactylus ) and the noble crayfish (Astacus astacus ) are common species and a traditional food source until the mid-20th century. In contrast, the stone crayfish (Austropotamobius torrentium ) remains the rarest one, being found only at upland locations (Pilis-, Börzsöny-, Visegrádi-, Kőszegi-mountains). Number of native crayfish populations remains steadily decreasing. Therefore, all of them are classified as endangered. The main reasons of their decline are anthropogenic impacts such as water pollution, habitat modifications, and introduction of non-native species. Recently, various examples of crayfish and shrimps released or escaped from indoor aquaria and garden ponds highlighted the pet trade as one of the most important pathways for introductions of non-native decapods. Nowadays seven non-native decapods have been reported in the wild in Hungary. The spiny-cheek crayfish (Faxonius limosus ) being first found in 1985, the signal crayfish (Pacifastacus leniusculus ) in 1998, the catadromous Chinese mitten crab (Eriocheir sinensis ) in 2003, the marbled crayfish (Procambarus virginalis ), and the red swamp crayfish in 2014. The results of our intensive research in recent years resulted in two further non-native crayfish. The individuals of the Australian redclaw crayfish (Cherax quadricarinatus ) and the Mexican dwarf crayfish (Cambarellus patzcuarensis ) (ref. 1) were found both in thermal waters and in the Danube River (ref. 2). Moreover, we defined their spread dynamics and the impacts on native faunal assemblages. Following the first record of red swamp caryfish in Carpatian Basin, the first established populations were found in a tributary stream and in the Danube River in 2016. The species composition of the habitats of red swamp crayfish were surveyed parallel with similar stream where do not occur the species. The results of our two-years survey showed that the non-native red swamp caryfish is capable to completely alter aquatic macrophytes, macroinvertebrates, fish, amphibians and aquatic reptiles. Our results are in line with previous findings on P. clarkii in Western Europe and elsewhere. The research was supported by the UNKP-17-3 New National Excellence Program of the Ministry of Human Capacities. (1) Weiperth, A., Gál, B., Kuříková, P., Bláha, M., Kouba, A., Patoka, J. (2017): Cambarellus patzcuarensis in Hungary: The first dwarf crayfish established outside of North America. Biologia 72 (12): 1529-1532. DOI: 10.1515/biolog-2017-0159 (2) Weiperth, A., Gál, B., Kuříková, P., Langrová, I., Kouba, A., Patoka, J. (2018) Risk assessment of pet-traded decapod crustaceans in Hungary with evidence of Cherax quadricarinatus (von Martens, 1868) in the wild. North-Western Journal of Zoology 14: e171303.