First record of the marine alien amphipod Caprella mutica (Schurin, 1935) in South Africa

We report the first discovery of the marine amphipod Caprella mutica (Schurin, 1935), commonly known as the Japanese skeleton shrimp, in South African waters. This amphipod is indigenous to north-east Asia and has invaded several regions, including Europe, North America, New Zealand and now South Africa. C. mutica was detected in scrape samples from the hulls and niche areas of four yachts resident to False Bay Marina, Simon's Town, on South Africa's South Coast. A total of 2,157 individuals were recorded, comprising 512 males, 966 females (20% of which were gravid) and 679 juveniles. The yachts upon which this amphipod was found were not alongside each other, suggesting that the species is widely distributed within the marina. The presence of C. mutica in South Africa has been anticipated, as previous work highlighted the climatic suitability of the region and the presence of vectors between South Africa and other invaded areas. The fast reproductive cycle of C. mutica, along with its high reproductive output, have important implications for its invasiveness in South Africa. Although it has already reached substantial densities in the marina environment, the extent to which it may invade natural habitats along the South African coast remains unclear. This paper comprises the first record of this amphipod from the African continent.