The spread of the alien oriental river prawn Macrobrachium nipponense (De Haan, 1849) (Decapoda: Palaemonidae) in the lower Danube, with the first record from Romania

Abstract

While monitoring the invasive freshwater invertebrates in Romania, specimens of a previously unknown prawn were reported on social media (Facebook) to occur in the lower reaches of the Danube and Pruth rivers. First individuals, including ovigerous females, were captured at Galați in a floodplain pond of the Danube in August 2021 and kept in an aquarium by a local hobbyist until their release back in the same place. In November 2021, several other specimens were observed and photographed in the lower Pruth at Slobozia Mare (Republic of Moldova). One adult male was captured by a crayfish catcher in November 2021 on the Chilia arm of the Danube Delta at Ceatalchioi. There were already several reports of numerous individuals captured by local crayfish trappers in the lakes Ligheanca, Băclăneștii Mari and Fortuna in the Romanian Danube Delta in July 2022. All these individuals were identified as the oriental river prawn Macrobrachium nipponense. The invasion history of M. nipponense in the area is inferred based on currently available literature and social media sources.