Rare snail that gives birth through neck returns from brink of extinction

An ultra-rare species of snail, believed to be extinct for decades and known for giving birth through its neck, is making a remarkable comeback. Approximately 1,000 Campbell's keeled glass snails are now establishing themselves in a secluded valley on Norfolk Island, thanks to a dedicated breeding and reintroduction program.

“

It was so thrilling actually because I'd spent a lot of time looking for these species before as a student and just thought it was completely gone, so it was very exciting to discover it.

This distinctively shaped snail, scientifically known as Advena campbellii, had vanished from sight for over 30 years and was officially declared extinct. Its rediscovery in 2020 by Norfolk Islander Mark Scott sparked hope. Australian Museum research scientist Isabel Hyman confirmed the find, describing the moment as "thrilling" after having searched for the species herself as a student.

“

This species hasn't been kept in zoo care or in captivity before so there was definitely a lot to learn and unfortunately you can't just compare snails to snails, they are all so niche in their requirements.

Despite the rediscovery, fewer than 50 snails were found in their natural habitat. This led to an Australian-first breeding program initiated in 2021 by the Taronga Conservation Society, in collaboration with the Australian Museum, Park Australia, Western Sydney University, and the Norfolk Island Regional Council. Starting with just 16 snails transported to Taronga Zoo in Sydney, the program faced challenges, including the loss of one snail during transport and initial difficulties in meeting the species' specific dietary and environmental needs in captivity.

“

It wasn't all smooth sailing and at one stage we actually got down to nine individual snails.

Keepers had to experiment extensively, learning the snails' picky requirements. They discovered that grinding food more finely, preparing it on soft surfaces, and adjusting light and humidity levels were crucial. After a challenging start, during which the population dwindled to nine individuals, the snails eventually began breeding successfully at Taronga. The process of birth, where live babies emerge from the snail's neck, is a unique and fascinating aspect of this species' biology. The successful breeding program has now allowed for the return of 1,000 snails to their native Norfolk Island habitat.

“

When there are so few left in the wild any little changes we made could be really nerve-racking.