The shells of these snails often grow to a length of 18 centimetres (7.1 in) with a diameter of 9 centimetres (3.5 in). Certain examples have been surveyed in the wild at 30×15 cm, making them the largest extant land snail species known.
Ecology
Like almost all pulmonate gastropods, these snails are hermaphrodites, having male and female sex organs. Each snail lays up to twelve hundred eggs per year. Achatina achatina is an important source of animal protein for West African forest-dwelling ethnic groups, and commercial farming of these snails holds great promise.
This species' substantial size and potential for rapid population growth can make the snail a serious pest when introduced to non-native ecosystems. The population size of this species can be curtailed through disease caused by the bacterium Aeromonas liquefaciens[9] but it often has no other natural enemies.