Scientists have discovered a faceless fish during a voyage to one of the deepest parts of the ocean ever visited—Australia’s eastern abyss.

The bizarre creature is only the second specimen of the species ever to be found, the first having been found by scientists on board the HMS Challenger, a research vessel that visited the waters off Papua New Guinea in 1873.

faceless fish photographer Asher Flatt Faceless fish, discovered on a voyage to Australia’s eastern abyss. Museums Victoria/CSIRO/Asher Flatt

The latest mission, called Sampling the Abyss, is headed by Australia’s Museums Victoria and CSIRO (Commonwealth Scientific and Industrial Research Organisation). The month-long mission involved 40 scientists studying the marine life that exists at depths of up to 4,000 meters (2.5 miles).

While the voyage will officially end on June 16, researchers have revealed some preliminary findings—including a host of species believed to be new to science.

Chief scientist Tim O’Hara, from Museums Victoria, Australia, told AFP that it is extremely dark at such great depths, so most creatures living there do not need eyes. Describing the faceless fish, he said: “It hasn’t got any eyes or a visible nose and its mouth is underneath.”

seacucumber_credit_Rob Zugaro Seacucumber, found on a voyage to Australia’s eastern abyss. Museums Victoria/CSIRO/Rob Zugaro

The mission is the first time the biodiversity living at these depths have been explored. O’Hara said: “The abyss is the largest and deepest habitat on the planet, covering half the world’s oceans and one third of Australia’s territory, but it remains the most unexplored environment on Earth. He added that the scientists on board believe around a third of the creatures they have found are new species. At the moment, they have collected several thousand specimens.

Other species discovered include carnivorous sponges, bright red rock crabs, blind sea spiders and coffinfish.

Dragonfish_Credit_Rob Zugaro - Copy Dragonfish, found on a voyage to Australia’s eastern abyss. Museums Victoria/CSIRO/Rob Zugaro

O’Hara said their findings will help researchers better understand the deep sea habitats off the coast of Australia: “The data gathered on this trip will be crucial to understanding Australia’s deep-sea habitats, their biodiversity and the ecological processes that sustain them. This will assist in its conservation and management and help to protect it from the impacts of climate change, pollution and other human activity,” he said in a statement.

Coffin Fish from 1000m Coffin Fish, found at a depth of 1,000 meters. Museums Victoria/CSIRO/Asher Flatt

Over the course of the voyage, scientists will visit seven different marine reserves. After specimens have been collected, researchers will map patterns of biodiversity and evolution, analyzing their chemistry and DNA to re-create seafloor food-webs. “We know that abyssal animals have been around for at least 40 million years, but until recently only a handful of samples had been collected from Australia’s abyss,” O’Hara said.