Establishment of the invasive Asian shore crab Hemigrapsus sanguineus (De Haan, 1835) (Crustacea: Brachyura: Grapsoidea) from the Cotentin Peninsular, Normandy, France

The occurrence of the invasive Asian shore crab Hemigrapsus sanguineus (de Haan, 1835), around the Cotentin Peninsular, Normandy, France, is reported. The northern and eastern Cotentin coasts are more densely colonised (maximum density ≅ 10 ind.m -2) than western shore, where the crab remains rare. These colonisation and establishment demonstrate probably the western progression of the species from its initial introduction into the Le Havre harbour during 1999.