Demon Shrimp

The Demon Shrimp, Dikerogammarus haemobaphes, which is a relative of the ‘killer shrimp’, has been found on the River Severn at Tewkesbury and Bevere near Worcester. It has also been found on two canals in Worcestershire. This is the first time this non-native shrimp, which has been shown to be invasive on mainland Europe, has been found in this country.

The shrimp was found after samples were taken from the River Severn by APEM for Severn Trent Water. Experts were then able to conclusively identify the species as Dikerogammarus haemobaphes. Shortly after, other populations were discovered on the Staffordshire and Worcestershire Canal and the Worcester and Birmingham Canal. The sites are spread over a distance of approximately 38 kilometres.

While this new invasive shrimp species is related to the ‘killer shrimp’, we are uncertain at this stage what its impact might be. Until we have better information we will, as a precaution, treat it as a high impact species. An immediate assessment of the risks of this shrimp has been commissioned.

We now have a dedicated team in place to establish how far the shrimp has spread along the river and canal network. The local response is also being supported by a National Task Group involving staff from Defra, Welsh Government and expert advisors from the Environment Agency, Natural England and the Countryside Council for Wales.

The Environment Agency and Canal & River Trust are urging all water users to help slow the spread of this invasive species by helping publicise the bio-security advice available at All water users should check, clean and dry all their equipment after use, before using it at another location. Boat users must be particularly careful to ensure that boats and kayaks are drained, cleaned and dried. Boat trailers must also be thoroughly cleaned after use. Anglers should ensure that nets and other equipment are cleaned and dried thoroughly.

If you think you have seen an unusual shrimp, please email a photograph to for identification.

David Throup, Environment Manager for the Environment Agency said, “We are concerned that this invasive species has been found in the Midlands. We now have a dedicated team whose focus is to establish the degree of the problem, and whether the shrimp has spread wider than the locations already found. We are treating this as a priority so that we can come up with a plan to help contain it’s spread as far as possible.”

Chris John, National Ecologist for the Canal & River Trust said, “As the charity responsible for caring for 2000 miles of canals and rivers across the country, one of our primary aims is to protect the nations waterways from invasive species such as this. We need the support of people that enjoy the waterways to prevent the shrimp spreading by checking, cleaning and drying any clothes, equipment or craft that could carry invasive species, before and after they visit the waterways, and by reporting any suspected sightings of the shrimp through the dedicated email address.”

MORE INFORMATION Contact Jessica Campbell on 0121 711 5855 / 5842 / 5829
(these numbers can also be used during an emergency to contact a duty press officer)

Notes for editors

National Task Group
The national response to this species in England and Wales is being led by a Task Group involving staff from Defra, the Welsh Government and expert advisors from the Environment Agency, Natural England and Countryside Council for Wales. The Task Group coordinates the implementation of national response measures and key actions to prevent further spread of D. Villosus and D. haemobaphes and protect vulnerable sites from invasion. This group reports to the GB Non-Native Species Programme Board who oversee non-native species management issues across Great Britain.

Dikerogammarus haemobaphes
This species originates from the Ponto-Caspian region of Eastern Europe around Black Sea, and has invaded Western Europe largely as a result of a canal link created between the Danube and the Maine, a tributary of the Rhine, in 1992.

It is up to 18mm long, similar in size to our native freshwater shrimp. It may have striped or spotted markings, with two distinctive humps on the tail. It prefers to live in zebra mussel beds, but will also use a range of other freshwater habitats for cover, including aquatic weeds, mud and gravel.

Dikerogammarus haemobaphes is the less aggressive relative of Dikerogammarus villosus, the ‘killer shrimp’. It is a rapid breeder, producing three generations per year, with each female laying 100 or more eggs. In Europe Dikerogammarus haemobaphes kills and competes with a range of native species, such as freshwater invertebrates, and particularly native shrimps. It also scavenges and eats plant matter. This alters the ecology of the habitats it invades.

For more information about non-native species visit:

To view the Invasive Non-native Species Framework Strategy visit