'Fierce deep-sea lizard' from Australia eats 'everything'

Australia's known for its array of terrifying predators - and it turns out that extends to its ocean waters too.

Researchers from the Commonwealth Scientific and Industrial Research Organisation (CSIRO) have trawled up a rare Bathysaurus ferox, which literally translates to "fierce deep-sea lizard".

"It's an ambush predator that waits for its prey, then once it grabs hold of something it can use these flexible teeth to move the prey into the back of its mouth," says zoologist John Pogonoski, on board the research vessel Investigator.

John Pogonoski with a Bathysaurus ferox.
John Pogonoski with a Bathysaurus ferox. Photo credit: CSIRO/Asher Flatt

In a blog post uploaded to the University of Tasmania's Marine Biodiversity Hub website, science communicator Asher Flatt called it a "terrifying terror of the deep".

"Once it has you in its jaws there is no escape: the more you struggle the further into its mouth you go."

Bathysaurus ferox lives as deep as 2.5km below the ocean's surface. Since they rarely come across one another in the dark depths of the Tasman Sea, they have both male and female organs - so every encounter is a potential mate.

A baby Bathysaurus ferox.
A baby Bathysaurus ferox. Photo credit: CSIRO/Asher Flatt

So few of them have been observed, no one's sure if like other similar "lizard" fishes Bathysaurus ferox can glow in the dark.

Ichthyologist John Sparks told Livescience scientists have tried putting them in tanks with shallow-water lizard fish species, but it never ends well because they "eat everything".

"They don't make good aquarium pets."