PT - JOURNAL ARTICLE AU - Marek Šmejkal AU - Ondřej Dočkal AU - Kiran Thomas AU - Lukáš Kalous TI - First record of highly invasive Chinese sleeper <em>Perccottus glenii</em> Dybowski, 1877 (Perciformes: Odontobutidae) in the Elbe River Basin, Czechia AID - 10.1101/2023.01.20.524995 DP - 2023 Jan 01 TA - bioRxiv PG - 2023.01.20.524995 4099 - http://biorxiv.org/content/early/2023/01/23/2023.01.20.524995.short 4100 - http://biorxiv.org/content/early/2023/01/23/2023.01.20.524995.full AB - The Chinese sleeper (Perccottus glenii) has invaded European freshwaters and we present evidence of its first documented occurrence in the Elbe River basin in Czechia. The individual fish was caught by a fisherman and posted on social media. After immediately contacting the person in question, we obtained a live fish from him. The Chinese sleeper appears to have been present in interconnected ponds and streams for ten years and may have spread over a larger area. We recommend that eradication measures be implemented to prevent further spread.Statement of Significance The Chinese sleeper has invaded many European countries in the last 50 years, and it is expected to invade western Europe because of the favourable conditions for its establishment. This finding indicates that it could spread in the Elbe River Basin, which could have serious impacts on floodplain and wetland ecosystems. To prevent this scenario, eradication measures should be implemented.Competing Interest StatementThe authors have declared no competing interest.