A diving expedition into a Nelson cave, one of the world's deepest, has uncovered three species Niwa says have never been seen before.

The National Institute for Water and Atmospheric Research (Niwa) is working to find names for the new species; a transparent crustacean, a gastropod snail and an oligochaete worm.

Found in the depths of the Pearse Resurgence - an underwater cave in the Mt Arthur Range near Nelson - a team of Australian divers who were mapping the cave made the discoveries and brought them back to Niwa.

Full story & video here http://www.stuff.co.nz/science/7172905/Deep-cave-dive-reveals-NZ-native/