Since 1600, Pacific island land snails have been plagued with extinctions, facing more species wipe-outs than seen in any other group of animals on Earth. Their luck, however, is changing as a big discovery recently published in the journal ZooKeys unveiled a new species of Hawaiian land snail, and it’s tiny.
Auriculella gagneorum, a minute snail that is dwarfed by a toothpick, was discovered in Oahu's Waianae Mountains, representing the first new species of a living Hawaiian land snail described in 60 years. The species sports a surprising variety of shell types, with characteristic candy stripes that make it resemble an old-fashioned barbers sign. The tiny mollusk "brings that little glimmer of hope that this isn't all a depressing story," said the study's lead author Norine Yeung, malacology curator at the Bishop Museum, in a statement.
It might seem like a lot of excitement for an animal that spans less than two-tenths of an inch in length, but even miniature land snails play a crucial role as decomposers and fungivores in Hawaii's ecosystems, essentially, as Yeung describes them, "our first recyclers.”
The victory came as part of a 10-year, large-scale survey of land snails that focused on 1,000 sites through Hawaii. Field discoveries were combined with observations from the Bishop Museum’s collection of land snails, unidentified specimens within which span back as far as the 1940s, and were compared to modern samples to get an idea of what they were looking at.
Now that A. gagneorum have been discovered, the researchers on the survey want to grow their population and have selected some snails to be incorporated into Hawaii's captive breeding program. Their name pays homage to the late Hawaiian naturalists Betsy and Wayne Gagne, who were "powerhouses for conservation," Yeung said. "They cared about the whole ecosystem, whether it was a tiny little bug or plants or one of Hawaii's charismatic, beautiful forest birds."
Hawaii once teemed with land snails, but its eclectic gathering of around 750 species has now shrunk by more than half. These vulnerable animals are heavily affected by habitat loss and invasive species such as rats and chameleons. An unfortunate attempt to rejuvenate some troubled species of snail saw the carnivorous rosy wolf snail brought in as a biological pest control for predatory African land snails, but the rosy wolf snail joined the African giants in chowing down on native species.
With such a troublesome past, it’s all the more important that even the smallest of land snails receive the pomp and ceremony they deserve. "This is a happy story where we discovered a snail that is still around," Yeung said. "There are so many things in our collection that we can no longer find in the wild. But in this snail's case, we can finally put a name to it and describe it, which is huge for the conservation of this species."