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This invasive fish can live for days on land, dragging itself along with its gills

Researchers think this walking fish could pose a threat to Australian wildlife. (Video: Dr. Nathan Waltham, James Cook University)

So, yeah. This is a fish very casually dragging itself through the mud by its gills. One that reportedly puffs up when eaten, suffocating its predators from beyond the pale. Nothing to see here.

[Walking fish raised on land mimic ancient evolutionary transition]

It also might pose a threat as an aggressive invasive species in Australia, so that's something to add to the (already abundant) nightmare fuel.

The climbing perch (Anabas testudineus), native to southeast Asia, has been working its way southward for years. In 2005 it was spotted on islands near mainland Australia, and now one researcher claims it could make it all the way to the continent. No one expects the little guys to swim very far (or walk very far, for that matter) but Nathan Waltham, a senior researcher in wetland ecology at James Cook University, claims that the fish is much more tolerant to saltwater than previously believed. That means it could presumably make its way to Australia on the bottom of a fishing boat.

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On recent trips to the islands of Boigu and Saibai -- technically part of Australia, but much closer to Papa New Guinea, where the fish was already known to thrive -- Waltham saw the species showing a tolerance for salt and a dominance over local species.

“It does seem to be able to handle a little bit of salt,” Waltham told the Telegraph. “In our trip up there in December we found it in some hyper saline water holes, so there is some ability to resist exposure.”

The fish could live for days on land moving from water hole to water hole, and would quickly establish itself and out-compete resident fish when it got there. Plus, Waltham reports, the fish were killing both land and sea creatures with their strong gill covers, which lodge in the throat of predators who swallow them. They use those strong, spiky gills to move themselves across land.

If island locals are able to control the climbing perch population -- and boats traveling from the New Guinea area to the Australian mainland are cautious about what tags along with them -- the tiny fish should never pose a threat. But if they do manage to get to the mainland, Waltham says, they could be quite dangerous for the local ecosystem.

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