Killer shrimp

Dikerogammarus villosus

Overview

Photo credit: ©Environment Agency
Killer shrimp - Dikerogammarus villosus
Habitat:
  • It is found in fresh water and brackish waters.

Description:
  • It has a laterally compressed, arched and semi-transparent body, reaching up to 30mm. It displays striped, spotted and uniform colour morphs, which is probably a form of camouflage from predators. It is an effective predator, with large mandibles aiding in that behaviour.
  • Download N.I.E.A. ID Guide

Origin and Worldwide Distribution:
  • It is native to the Black Sea and Caspian Sea.
  • It is now found in Austria, Belarus, Belgium, Czechia, France, Germany, Hungary, Italy, the Netherlands, Poland, and Serbia. There are a few occurrences in the United Kingdom.

Potential or Known Impacts:
  • It is an effective predator due to its larger size and large size. It readily alters food webs after replacing native amphipods by consuming fish eggs and fry, and filter-feeding on microalgae.
  • It is highly adaptable to different habitats, and is able to move to and colonise new areas.

How could it get here?
  • It is often spread by transportation inside boats and ships to a wider range of environments. It can also spread by using rivers, and manmade waterways.

Is it found in Ireland or Northern Ireland?
  • It is not present in Ireland or Northern Ireland.

Methods for Prevention:
  • It is important to create horizon scanning plans that can be used, as they have early-warning signs, like maps of the current distribution.
  • If you are using waterways for recreation or work, it’s important to check and clean your equipment before letting it dry to prevent the spread of this species.
  • Report all sightings.

You can help by reporting any sightings:

Species Related Files:

Invasive Species Ireland

Invasive Species Ireland