New fish species discovered in Peru-Chile trench

Marine biologists claim to have discovered three new fish species while undertaking deep-water ocean trawls of the Peru-Chile trench off South America.

An international team, led by the University of Western Australia, made the discovery while undertaking an expedition to study mesopelagic fish (midwater fish that live at depths of over 100 metres) and how they use bioluminescence (self generated light) to survive at these depths.

Working with teams of scientists from Britain, the US, Japan, Germany and other parts of Australia, 20 trawls were undertaken at depths ranging from 100 metres to 1,700 metres.

"It is suspected that at least three new fish species may have been discovered but this awaits verification by the experts on board from the Australian and Victorian museums," Professor Shaun Collin, who led the team, said.

He added: "But how do these deep-sea fishes manage to migrate upwards nearly 1000 metres every night to feed in the nutrient rich upper water layers when there is little or no sunlight to signal night and day?

"We're interested in what the function of the pineal is in the deep sea and whether these image-forming eyes also play a role in setting their circadian (daily) rhythms."