A new study has found the primitive hagfish, also known as a "snot eel" can defend itself by releasing a noxious slime that chokes would-be predators.The long, thin hagfish are almost blind and have no jaws but use tooth-like rasps to prey on dead and dying fish. Fossil record suggests hagfish have evolved little over 500 million years.
Researchers from The University of Western Australia, New Zealand's national museum Te Papa and Massey University in Auckland recorded underwater footage which reveals for the first time, the hagfish repelling sharks and bony fish using its gooey defence mechanism. The study was published in Scientific Reports.
Associate Professor Euan Harvey, from UWA's Oceans Institute, said the footage was recorded in deep water off New Zealand's Three Kings and Great Barrier Islands and captured the hagfish feeding while being attacked by various predators.
"As soon as it is attacked, the hagfish releases a mucus-like substance from a battery of slime glands, which makes predators gag before quickly retreating," Professor Harvey said.
"While scientists have known about the protective qualities of the hagfish's slime for some time, this is the first time anyone has been able to capture it in the act of repelling a predator."
Professor Harvey said the researchers had also found the hagfish was not only an ocean scavenger but also a predator.
"The footage showed it has an unusual method of burrowing into sand in pursuit of a red bandfish and knotting its tail for extra leverage," he said. "It then captures the prey before unknotting itself and emerging from the sand."