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The strange reproductive habits of a large, carnivorous New Zealand snail
were once shrouded in mystery. Now footage of the snail laying an egg from
its neck has been captured for the first time, the Department of Conservation said today.


What looks like a tiny hen's egg is seen emerging from an opening below the head of the Powelliphanta augusta snail, a threatened species endemic to New Zealand.


The video was taken at a facility on the West Coast, where conservation
rangers attempting to save the species from extinction have cared for a population of the snails in chilled containers for nearly two decades.


The conditions in the containers mimic the alpine weather in their only
former habitat - a remote mountain they were named for, on the West Coast,
that has been engulfed by mining.


Observing their habits
Lisa Flanagan from DOC, who has worked with the creatures for 12 years, said the species still holds surprises.


"It's remarkable that in all the time we've spent caring for the snails, this is the first time we've seen one lay an egg," she said in a statement.


Like other snails, Powelliphanta augusta are hermaphrodites, which explains
how the creatures can reproduce when encased in a hard shell. The
invertebrate uses a genital pore on the right side of its body, just below
the head, to simultaneously exchange sperm with another snail, which is
stored until each creates an egg.


A long but slow reproductive life
Each snail takes eight years to reach sexual maturity, after which it lays about five eggs a year. The egg can take more than a year to hatch.


"Some of our captive snails are between 25 and 30 years old," said Flanagan. "They're polar opposites to the pest garden snail we introduced to New
Zealand, which is like a weed, with thousands of offspring each year and a short life."


The dozens of species and subspecies of Powelliphanta snails are only found
in New Zealand, mostly in rugged forest and grassland settings where they are threatened by habitat loss.


They are carnivores that slurp up earthworms like noodles, and are some of
the world's largest snails, with oversized, distinctive shells in a range of rich earth colours and swirling patterns.


A political storm
The Powelliphanta augusta was the centre of public uproar and legal
proceedings in the early 2000s, when an energy company's plans to mine for
coal threatened to destroy the snails' habitat.


Some 4000 were removed from the site and relocated, while 2000 more were
housed in chilled storage in the town of Hokitika to ensure the preservation
of the species, which is slow to breed and doesn't adapt well to new habitats.


In 2011, some 800 of the snails accidentally died in a DOC refrigerator with faulty temperature control.


But the species' slow survival continues: In March this year, there were
nearly 1900 snails and nearly 2200 eggs in captivity, the conservation agency said.

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