An alert to all anglers has been issued about so-called killer shrimps.
Trouties found a new invasive species crawling up their waders at Graffham Water, Cambs, in September. Now scientists say they've spread to Wales.
The shrimp, or Dikerogammarus villosus, is an invasive and aggressive species from eastern Europe, which kills the young of native fish.
Anyone who spots one is being urged to call the Environment Agency. Anglers are also being urged to ensure nets and other gear are dried out between trips
Mark Lloyd from the Angling Trust said: "The future of the £3.5 billion angling industry is at stake, along with the beloved pastime of millions of anglers and the country's aquatic biodiversity.
"We must all take rigorous steps to ensure that this pest is not allowed to spread any further and wreak havoc on the nation's water environment."
Click here for more on the menace.