First record of highly invasive Chinese sleeper Perccottus glenii Dybowski, 1877 (Perciformes: Odontobutidae) in the Elbe River Basin, Czechia

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.