An international team of scientists is halfway through a month-long journey surveying the ocean floor along Australia's eastern abyss, a previously unexplored stretch of marine territory reaching depths of between 4,000 and 6,000 m (13,100 and 19,700 ft). So far, the team has uncovered a startling array of bizarre abyssal animals, including a weird faceless fish and blind deep-sea spiders.

Aboard the research vessel Investigator are a collection of scientists from research agencies and museums around the world. The voyage, called Sampling the Abyss, is spearheaded by Museums Victoria and the Commonwealth Scientific and Industrial Research Organization (CSIRO).

The team on the board the vessel has been blogging its adventures over at Blogging the abyss, and their daily discoveries have been exciting to follow. One of the most striking finds came recently when they pulled a strange faceless fish onto the deck from 4,000 m below the surface.

"Everyone was amazed," writes Dianne Bray from Museums Victoria. "We fishos thought we'd hit the jackpot, especially as we had no idea what it was."

As the team was excitedly brainstorming names for its new discovery, an eel expert suggested the species looked like something seen in an old textbook. It was revealed that the team had found a cusk eel, or Typhlonus nasal.

The species is rare, but hasn't been found in Australian waters for over 100 years. In fact, the very first specimen of the fish was collected in the Coral Sea off the coast of Australia in 1874 by the HMS Challenger during the world's first large-scale oceanographic expedition.

Bray points out how amazing the Challenger's achievements were considering the technology they were working with. In 2017 the process of deploying and retrieving collection gear involves hours of skillful work, and that is just dealing with depths of 4,000 meters.

"So just imagine the effort it must have taken for the Challenger's crew to trawl down to 6,000 m depths using piano wire, without our high-tech winches and computers!" Bray writes.

Among the other odd creatures found in the depths of the abyss were several species of sea spiders, or pycnogonids. Recognized as some of the oldest surviving arthropods to inhabit the earth, the specimens found on this current voyage have been unexpectedly large and decidedly alien-looking.

The expedition still has two more weeks of weird and wonderful discoveries to uncover as the vessel travels up the eastern coast of Australia towards its final destination near Brisbane.

Follow the team's adventure on their blog here.

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