The bloody red shrimp (Hemimysis anomalia) is an invasive crustacean species in the British Isles, first detected in 2004. Native to the Ponto-Caspian region, it has spread to European freshwater and brackish ecosystems via ballast water. In the UK, it inhabits lakes, reservoirs, and slow-moving rivers, often forming swarms in sheltered areas. Hemimysis anomalia is an opportunistic feeder, preying on zooplankton and competing with native species for resources, potentially disrupting food webs. Its rapid reproduction and adaptability make it a concern for biodiversity and ecosystem balance.
