ATTACK of the cloning snails might sound like the name of a B-grade movie, but the snails are real and the phrase perfectly describes Adrian Dusting's research.
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Potamopyrgus antipodarum is the New Zealand mud snail overtaking other bug life throughout waterways in south-eastern Australia. Nobody knows how it came across the Tasman Sea, although some speculate it came aboard an imported trout or travelled on a fisherman's waders.
Somewhere along the way, the four-millimetre-long mollusc managed to get rid of its arch-nemesis, a parasitic worm native to New Zealand that keeps snail numbers down in its home country by sterilising them.
''The earliest records we have of the snail in Australia date from 1872 in Tasmania, and 1883 on the mainland in Victoria,'' Mr Dusting said. ''These are both specimens held in Australian museums.''
Since then, the snail has been an unstoppable force in Australia, helped by its ability to survive days without water and hide safely in its shell if eaten by fish until it comes out the other end.
While resistance to digestion and desiccation keep the snail alive, its gift for reproducing without any sexual partners is the key to its long-term domination.
''Each female can produce 240 young and these can start to reproduce within months,'' Mr Dusting said.
The freshwater ecologist has hundreds of the snails in his University of Canberra office, where he is finding out whether the different genotypes found in Australia are the product of various environments the snail has encountered here.
''This allows us to forecast how likely the snail is to keep expanding its invasion and predict where that might occur,'' he said.
The PhD student works from a small laboratory containing hundreds of the creatures, which have also invaded Europe, Asia and the United States. He said he first became interested in them while testing waterways and finding they were edging out other bug life that helped process carbon and nitrogen.
''You want to find strong species diversity for a healthy waterway,'' he said.