During a 30-day expedition to the Mariana Trench (considered to be the deepest place on Earth), a team of researchers from the University of Hawaii discovered a new species of fish thriving at the depth of 8 143 meters, thus beating the previous depth record by almost half a kilometer.
“We think it is a snail fish, but it’s so weird-looking; it’s up in the air in terms of what it is,” said Alan Jamieson from the University of Aberdeen. “It is unbelievably fragile, and when it swims, it looks like it has wet tissue paper floating behind it. And it has a weird snout – it looks like a cartoon dog snout.”
The voyage, titled the Hadal Ecosystem Studies (HADES), responsible for this exciting new discovery, will help scientists answer some important questions about our planet’s largest and least explored habitat. Among other things, the study authors hope to learn what kinds of organisms live there and how they adapt to the prevailing conditions.
Operating from the Schmidt Ocean Institute’s research vessel Falkor, the international team of explorers deployed five deep-sea vehicle systems, known as landers, at over 90 locations along the trench, with depths ranging between 5 000 and a little over 10 000 metres. This gradual approach was chosen in order to better understand the interplay between life and geologic processes across the entire hadal zone, which lies from a depth of around 6 000 metres to the very bottom.
“Many studies have rushed to the bottom of the trench, but from an ecological view that is very limiting,” explained co-chief scientist Dr. Jeff Drazen. “It’s like trying to understand a mountain ecosystem by only looking at its summit.”
The previous record holder, a species of snail fish called Pseudoliparis amblystomopsis, was filmed in the Japan Trench and the Pacific Ocean in 2008 at a depth of 7 700 metres. Currently, scientists managed to document over 360 different species of this family, found both in shallow and extremely deep waters.
The new species, spotted at a staggering depth of over 8 kilometres, stunned even the seasoned researchers onboard the vessel. The white translucent fish had broad wing-like fins, an eel-like tail and slowly glided over the bottom.
“When findings and records such as these can be broken so many times in a single trip, we really do get the feeling we are at the frontier of marine science,” enthused Jamieson.
It is believed that the reason why these fish are able to endure such crushing depths is a chemical called trimethylamine oxide (TMAO), which was found to be present in their bodies at a higher concentration. This compound helps proteins maintain their shape as pressure increases. According to recent research conducted by Jamieson, fish are probably unable to hold enough TMAO in their cells to live below 8 200 metres, meaning this new species might be the permanent record holder.