AUK-Japan team found the 17-strong shoal at depths of 7.7km (4.8 miles)in the Japan Trench in the Pacific - and captured the deep sea animalson film.

Thescientists have been using remote-operated landers designed towithstand immense pressures to comb the world's deepest depths formarine life.

No-one has ever seen fish alive at these depths before

"There are three problems: the first is food supply, which is very remote and has to come from 8km (5 miles) above.

"There is very high pressure - they have to have all sorts of physiological modifications, mainly at the molecular level.

And the third problem is that these deep trenches are in effect small islands in the wide abyss and there is a question of whether these trenches are big enough to support thriving endemic populations

Becausethe fish live in complete darkness, they use vibration receptors ontheir snouts to navigate the ocean depths and to locate food.