A deep sea fish that uses gill-clogging slime to repel attackers has been caught on camera for the first time by Kiwi researchers.
Video footage from a study by Te Papa and Massey University researchers of New Zealand's deep sea animal diversity shows the hagfish - also know as the snot-eel - repelling sharks and other fish when bitten.
The attacking fish appear to gag on the mucus-like substance before releasing the hagfish and swimming away.
"Our video footage in New Zealand waters has proven that hagfish secrete slime at an incredibly fast speed when under attack by predators such as large sharks or bony fishes," said Te Papa's Vincent Zintzen, lead scientist on the project.
The footage, taken around Three Kings and Great Barrier Islands, also shows the hagfish is a capable hunter, not just an ocean scavenger.
One video shows it burrowing into the sand after a red bandfish before making a knot with its tail for leverage to drag out its prey.
The fish had previously been known to feed on carcasses of dead whales, fish and invertebrates.
Massey University Professor Marti Anderson, co-author of the study, said the footage was a good indicator of why the hagfish had survived for about 300 million years.
Professor Anderson said so little was known about the deep sea that merely dropping cameras into the water had a high probability of new discoveries being made.
Scientists have deployed cameras at depths of 50 to 1500 metres around New Zealand for the study since 2009.
More than 1000 hours of footage has been collected off the Kermadec Islands, Three Kings Islands, Great Barrier Island, White Island and Kaikoura.
Surveys off the Otago Peninsula and as far as the Auckland Islands will be conducted in 2012.