A report from National Geographic on the B-grade horror movie plot, but very real environmental disaster, of giant African snails "thriving in nearly every state" of Brazil.
The giant mollusks, which can grow to 20cm long and weigh up to half a kilogram, were first introduced as a gourmet delicacy, but have now adapted to Brazil's climate so well that experts think they will be impossible to eradicate :
There is no record of when the species was first imported, but an agribusiness fair in southern Brazil in 1988 was probably pivotal in sparking the invasion.The snails are believed to be responsible for infecting people with meningitis.
At the fair, people sold kits with snails and brochures detailing how to raise them.
At first the African snails seemed promising for food: They had more meat, grew faster, and were more resistant to disease than the garden snail. The African snail was also cheaper to keep.
Brazilians countrywide began growing the giant snail in their backyards, planning to sell the mollusks to fancy restaurants.
Yet eating escargot is unusual in Brazil, and the few diners who would pay to eat the delicacy were not willing to substitute it for a new species with different texture and taste—and suspicious origin. This resulted in thousands of frustrated people with unwanted snails slithering through their backyards.
Most of the snails were then released in the wild, where they rapidly grew in number.