Invasives Blog

Last month anglers at Grafham Water reservoir in Cambridgeshire, UK spotted the invasive killer shrimp Dikerogammarus villosus. The first sighting of this ferocious little beast in the UK has instigated the GB Non Native Species Secretariat (NNSS) to issue a species alert as part of the GB rapid response protocol in an attempt to contain and monitor its spread.


The Killer Shrimp Dikerogammarus villosus (Picture courtesy of Michal Grabowski)


Native to the Ponto-Caspian basin in Eastern Europe, the killer shrimp has spread throughout Western Europe over the last 10 years. Dikerogammarus villosus is much larger than our native freshwater shrimps, up to 30mm, and is able to withstand a wide range of environmental tolerance including increased salinity and a temperature range of 0 to 30oC. The shrimp certainly lives up to its name as it has a voracious appetite which includes young fish and freshwater invertebrates, and it is known to even kill its prey and discard it leaving it uneaten.

Although it is unknown exactly how the shrimp came to present at Grafham Water reservoir, the Environment Agency think it may have hitch a ride on boating equipment previously used in mainland Europe or by migrating birds. Preventative measures are currently in place to avoid further spread including the inspection and cleaning of any recreational equipment used in the water. The NNSS request any further sightings are reported along with a photograph and location details to:

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