A new invasive species has been discovered in Finland.

The species known as the 'killer shrimp' (Dikerogammarus villosus in Latin) has been found in the west-coast port of Rauma, the Finnish Environment Institute (Syke) said on Thursday.

The crustacean, which can grow to be 3cm long, is a threat to invertebrate species, especially in brackish waters, but also in inland waters.

Thus it could threaten biodiversity in the Baltic Sea, which has low salinity.

The species, which originates around the Black Sea and Caspian Sea, moved into European seas and rivers in the 1990s. In the 2000s it has also spread to European lakes.

The BBC dubbed it a 'killer shrimp' when it was first found in British waters in 2010. According to the UK Environment Agency, the animal often kills its prey and leaves it uneaten.

Seen in a Swedish lake 3 years ago

The crustacean has previously been found along the coasts of Latvia, Lithuania and Germany. The species has also been observed in both Danish and Swedish lakes, appearing in Sweden’s Vättern lake in the spring of 2023, then its northernmost confirmed sighting.

According to Syke, the crustacean is spread by ships as well as by small boats that sail between different bodies of water. To prevent the spread of non-indigenous alien species, it is important that all boaters treat and clean their boat hulls, the institute said in a press release.

The number of invasive species has increased markedly in Finnish waters during this century, with 20 new species detected in the past 30 years.