Brush-clawed shore crab

Hemigrapsus takanoi


Photo credits: ©Arjan Gittenberger; ©Hans Hillewaert
Hemigrapsus takanoi - brush-clawed shore crab
  • H. takanoi is a small crab, reaching 2.5cm in length across its square cephalothorax. It is dark in colour, ranging from greyish to greenish to brown; its legs are banded. The males have a dense tuft of yellow bristles on their claws
  • It is found in intertidal areas of mudflats, estuaries and lagoons.

Origin and Worldwide Distribution:
  • This species is found in Japan and Korea. Its wider distribution is to be yet to be confirmed as it has been distinguished from a similar species.
  • It is invasive in Belgium, France, Germany, the Netherlands, and Spain.

Potential or Known Impacts:
  • It may outcompete native crab species for food and shelter. It has a highly reproductive potential, and the ability to grow quickly. It has a broad diet, and may predate on native shellfish.

How did it/could it get here?
  • It could be spread by hull-fouling from ships or by their ballast water.
  • Planktonic larvae may be moved by water currents. Adults may be hitchhike in narrow crevices on ropes, anchor boxes or in farmed oyster boxes.

Is it found in Northern Ireland?
  • It is not found in Northern Ireland

Methods for Prevention:
  • Do not introduce.
  • Make sure that all equipment is cleaned before moving between different water bodies.
  • Do not move water from one water body to another.
  • Report all sightings.

You can help by reporting any sightings: @ the Centre for Environmental Data & Recording (CEDaR) - Or via the iRecord App. For further queries, you can contact the Invasive Non Native Species (INNS) Team in the Northern Ireland Environment Agency on 028 9056 9558 or Email:  

Species Related Files:

Invasive Species Ireland

Invasive Species Ireland