Alien and invasive fresh water Gastropoda in South Africa

Ten species of freshwater gastropod have been introduced into South Africa, mostly through the aquarium trade. Two of these, Lymnaea columella (Lymnaeidae) and Physa acuta (Physidae), have been invasive in river systems across the country for many years, probably since the 1940s or 1950s, and two recent arrivals, Tarebia granifera (Thiaridae) and Aplexa marmorata (Physidae), are spreading. Research on one of the well-established invaders, P. acuta, is reviewed and updated and a suite of attributes is identified that may have enabled it to become invasive.