New species of deep-sea fish discovered in Atacama Trench

A new small blue snailfish is changing our understanding of the world's deepest fishes.

In 2018, an international team of scientists studied the Atacama Trench, an expansive trench that runs along the west coast of South America as a deep underwater valley that mirrors the Andes Mountains.

The team, including Newcastle University scientists, deployed free-falling landers to sample the sparse deep-sea creatures around cameras and traps with bait. Two lander systems from Newcastle University recorded three types of hadal snailfish and one of them was not like the others.

The small blue fish, seen from about 6,000 to 7,600 m deep, doesn't look like other hadal snailfish. With large eyes and striking colour, it resembles other species of snailfishes that are found living in much shallower waters.

The team used a 3D x-ray technique called microcomputed tomography (micro-CT) and DNA barcoding to see where the new species fit within the snailfish family.