'Cannibal Snails' Eat Species of Tiny Tree Snail into Extinction


The survival of an entire species of "incredibly endangered" tree snails has just been entrusted to the British Zoo. The population of tiny tree snails--they grow to be only a few millimeters long--has been decimated, eaten into extinction by a larger "cannibal snail." Called the Rosy Wolfsnail, it arrived as an invasive species to the tree snail's natural habitat of French Polynesia in the 1970s. The larger cannibal snails, along with habitat loss, have pushed the tree snail to extinction in the wild--there are now only 88 left in the world, in a lab in England. But the British Zoo intends to save them . . .

The BBC explains that British Zoo hopes to save the species through a careful breeding program in a climate-controlled environment. So far, 15 new baby snails have been produced, with the smallest of the bunch measuring 2 mm. Fingers are certainly crossed for the survival of the ultra-endangered species. But what about the cannibal snails that pushed them to the brink?



Keeper Grier Ewins at the British Zoo tells the BBC that: "Tree snails are incredibly endangered, with Partula faba being one of the most endangered of them all - they really are on the edge of survival." And here's how they got that way:

Invasive snails that were introduced to the French Polynesian islands in the 1970s decimated the tree snails. Between the mid 1970s and mid 1990s, an estimated 80% of tree snail species were lost. Loss of habitat, due to aggressively spreading plants such as the South American velvet tree, is also affecting wildlife on the islands.


The dreaded cannibal snail, the rosy wolfsnail, Euglandina rosea via Xenogere

And yes, the cannibal snails really do just that--they devour smaller snails, and do so at voracious rates. Cannibal snails are endemic to parts of North and South America, so when they arrived on the shores of the islands of French Polynesia, the tiny tree snails that lived there were defenseless: it only took 20 years for them to all but wipe out the entire population.

1st photo: The cannibal snail in action. Photo via AAAS
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