The common boa is a popular captive snake in the reptile industry. However, under the NEMBA Alien and Invasive Species regulations, a permit is required to keep them in KwaZulu-Natal, the Eastern Cape, Limpopo and Mpumalanga. There is concern that if these snakes escape captivity, they could survive in the warm climate offered by these provinces.
The North America bluegill sunfish was introduced to South Africa in 1938 as a fodder food for bass. Like bass, they have spread far and wide and in waterways where they have few predators, their population can grow rapidly and outcompete indigenous fish such as tilapia. It is found throughout most rivers and dams in southern and eastern South Africa.