Research Paper

Macrobrachium nipponense (De Haan, 1849) continues to spread in the Danube: first records in Germany and Hungary

¹ Faculty of Fisheries and Protection of Waters, South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, University of South Bohemia in České Budějovice, Zátiší 728/II, CZ – 389 25, Vodňany, Czech Republic
² Nature Conservation Specialist at the Environmental Office of the City of Passau, Rathausplatz 2, D – 94032, Passau, Germany
³ Water Warden at the Verein der Heiliggeist-Stift-Fischer “Apostelfischer” Passau e.V., Schießstattweg 85c, D – 94032, Passau, Germany
⁴ HUN-REN National Laboratory for Water Science and Water Security, Institute of Aquatic Ecology, Centre for Ecological Research, 29 Karolina Road, Budapest, H – 1113, Hungary
⁵ HUN-REN Institute of Aquatic Ecology, Centre for Ecological Research, 29 Karolina Road, Budapest, H – 1113, Hungary
⁶ Department of Systematic Zoology and Ecology, Institute of Biology, ELTE Eötvös Loránd University, Pázmány Péter ave 1/C, H – 1117, Budapest, Hungary
⁷ Technisches Büro Zauner GmbH, Marktstrasse 35, A – 4090, Engelhartszell, Austria
⁸ BOKU, University of Natural Resources and Life Sciences, Vienna, Institute of Hydrobiology and Aquatic Ecosystem Management, Gregor Mendel Strasse 33, A – 1180, Vienna, Austria
⁹ Independent Hydrobiologist, Budai Nagy Antal utca 14, HU – 2131, Göd, Hungary
¹⁰ Department of Zoology and Fisheries, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Kamýcká 129, CZ – 165 00, Prague, Czech Republic
¹¹ Department of Preschool & Primary Education, Faculty of Education, Jan Evangelista Purkyně University in Ústí nad Labem, Pasteurova 1, CZ – 400 96 Ústí nad Labem, Czech Republic
¹² Department of Biology, Faculty of Science, Humanities and Education, Technical University of Liberec, Studentská 1402/2, 461 17 Liberec, Czech Republic

^* Corresponding author: akouba@frov.jcu.cz

Received: 2 February 2025
Accepted: 25 March 2025

Abstract

This article presents the first records of the non-native Asian caridean shrimp Macrobrachium nipponense in Germany (Racklau Harbour, Passau) and Hungary (Lipót, Szigetköz floodplain), both discovered in 2023. Based on initial monitoring, both populations appear to be already established, and may serve as source populations for further spread, particularly downstream along the Danube River. The article explores the potential for upstream expansion from the lower Danube, where the species has been recently reported, as well as possible introduction pathways. We examined its ecological roles and potential impacts, which could be significant. Given the lack of effective eradication methods, efforts should prioritise minimising—and ideally preventing—further human-assisted spread. This should be underpinned by general environmental education and responsible pet ownership, potentially including a market ban, given the species' characteristics and its temperature tolerance across much of Europe. A deeper understanding of its interactions with both native and non-native species is needed. We call for intensified monitoring, particularly in suitable habitats such as harbours, using both conventional and eDNA methods to gain insights into its potential future distribution, and to reconstruct introduction pathways to inform management strategies.