Partula snails  (Partula spp)

In a tragic and calamitous story, humans are responsible for the extinction, or extinction in the wild, of 64 species of Partula snails in the recent past. In the 1800s a budding snail farmer introduced the large and edible giant African snail (Achatina fulica) to the islands of the Pacific Ocean in an attempt to profit from providing a new source of food to the islands’ human inhabitants. His venture failed for economic reasons and the snails were released. They became an agricultural pest, prompting a response from the authorities to introduce the predatory carnivorous snail Euglandina rosea to the islands to control giant African snail numbers. A lack of forethought and contained experimentation is evident, as the carnivorous Euglandina did not prey on the giant African snail as expected, instead consuming and decimating the majority of Partula snail species, rapidly driving 50 species to complete extinction. Habitat destruction has compounded the snails’ decline (2).

In a desperate attempt to salvage this genus, many animal collections have joined in efforts to gather sufficient numbers of several Partula species to breed them in captivity. Captive breeding programmes have run at the Shedd Aquarium, Detroit Zoological Park, the Zoological Society of London, and Jersey Zoo amongst others. The Zoological Society of London released captive-bred snails into a protected area on Moorea Island in August 1994. However, extensive release of captive-bred snails is not possible until Euglandina rosea has been exterminated from the islands. This sad loss to global biodiversity serves as a lesson of the ignorance of man and the consequences of the introduction of non-native species. Introduced species remain the second biggest cause of species loss after habitat destruction (2).