Invasion biology of the Asian shore crab Hemigrapsus sanguineus: A review

The Asian shore crab, Hemigrapsus sanguineus, is native to coastal and estuarine habitat along the east coast of Asia. The species was first observed in North America near Delaware Bay (39°N, 75°W) in 1988, and a variety of evidence suggests initial introduction via ballast water early in that decade. The crab spread rapidly after its discovery, and breeding populations currently extend from North Carolina to Maine (35°–45°N). H. sanguineus is now the dominant crab in rocky intertidal habitat along much of the northeast coast of the USA and has displaced resident crab species throughout this region. The Asian shore crab also occurs on the Atlantic coast of Europe and was first reported from Le Havre, France (49°N, 0°E) in 1999. Invasive populations now extend along 1000 km of coastline from the Cotentin Peninsula in France to Lower Saxony in Germany (48°–53°N). Success of the Asian shore crab in alien habitats has been ascribed to factors such as high fecundity, superior competition for space and food, release from parasitism, and direct predation on co-occurring crab species. Laboratory and field observations indicate that H. sanguineus is a generalist predator with potential for substantial effects on sympatric populations of mollusks and crustaceans. However, broad ecosystem effects and actual economic impact are unclear. The literature on H. sanguineus is limited in comparison to better known invasive species like the European green crab (Carcinus maenas) and the Chinese mitten crab (Eriocheir sinensis). Nevertheless, there are substantial bodies of work on larval biology, trophic ecology, and interspecies competition. This paper presents a review of the biology and ecology of invasive populations of the Asian shore crab H. sanguineus in North American and European habitats.

► Predatory potential of Hemigrapsus sanguineus has been demonstrated.
► Displacement of native crab species by H. sanguineus has been heavily studied.
► Larval settlement and metamorphosis have received considerable attention.
► Larval swimming behavior and transport are poorly understood.
► Community-level and economic effects are not well demonstrated.