Spread of African land snails

Question

Spread of African land snails

Answer

The genus _Achatina _is comprised of around 200 species of large land snails found throughout Sub-Saharan Africa. The most commonly known are Achatina achatina, the giant African land snail, and Achatina fulica, the giant East African land snail. While A. achatina grows to be the largest known land snail, more research is focused on A. fulica due to it being an invasive species and a vector for some important human and plant pathogens.

Giant land snails are edible, if cooked properly. In many regions in Africa, snails are collected for food, and are thought to be an important resource for many jungle tribes. However, the snails can carry a variety of serious or life-threatening human parasites, including the nematode Angiostrongylus, or rat lungworm (which can cause fatal meningitis), tapeworms, whipworms and trematodes which cause schistosomiasis. These are often contracted by eating undercooked snail, but people can be infected through contact with the snail’s mucus. In some instances, people have caught rat lungworm from vegetables that have been contaminated by the snails.

These diseases make the snail’s invasive tendencies even more concerning. The snails have been spread to many new locations, often accidentally, or as pets which have escaped. New colonies can be formed by a single fertilised individual, and have done so in China, India, parts of the US and a great number of islands in the West Indies, and Pacific and Indian Oceans, where they threaten important crops and rare and unique island species.

In Hawaii, two species of snail predators were introduced in an attempt to eliminate the giant land snails; the rosy wolfsnail, and the New Guinea flatworm, both carnivorous organisms that commonly prey on snails. However, the foreign species showed little interest in the giant land snails, instead devastating the unique native snails, including many species of Partula, and the O’ahu tree snail.

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