Western pea crabs Pinnixa occidentalis Rathbun 1894 (Brachyura: Thoracotremata: Pinnotheroidea) invade Saldanha Bay, South Africa

The arrival and spread of the introduced western pea crab Pinnixa occidentalis Rathbun 1894 in South Africa is documented. The crab originates from the Pacific coast of North America and was first recorded in Saldanha Bay in 2004, although its identification was only confirmed in 2010. Subsequent surveys have shown the crab population to be increasing rapidly in both distribution and density, although it remains confined to the Saldanha Bay–Langebaan Lagoon system. The ecological impacts of the invasion are yet to be determined