Asian shore crab

Hemigrapsus sanguineus

The Asian shore crab (Hemigrapsus sanguineus) occurs naturally in cold and temperate waters in the western parts of the Pacific Ocean but has spread to both sides of the Atlantic. The species inhabits both salt and brackish waters and seems to prefer hard substrates, such as rocky shores or oyster reefs. However, the habitat of this species varies and they can also be found on softer sediment bottoms.

This crab has a square carapace that can be up to 40 mm wide and is therefore relatively small in comparison to the Swedish native shore crab, which can be considerably larger. The color of the Asian shore crab varies between green, red and purple with darker spots, and it has darker bands on the legs which distinguish it from the brush-clawed shore crab and our native unstriped beach crab. Characteristic of this species are the small blisters found between the claws in fully grown males.

The first find of the Asian shore crab in Swedish waters was found on Öckerö in Gothenburg archipelago in 2012 and has since spread along the Swedish west coast. Since 2019, it is considered that the species is established and reproducing on the Swedish west coast, as several finds of both roe-bearing females and juvenile individuals have been found.