This mysterious new creature's been spotted on the bottom of the Indian Ocean. Photo / The Five Deeps Expedition
A strange and mysterious creature has been found in the depths of the Indian Ocean, potentially for the first time.
In the murky waters of the Java Trench — believed to be the deepest point in the Indian Ocean — diver Victor Vescovo has come across an unusual creature during his trip with The Five Deeps Expedition.
As part of a film for the Discovery Channel, Mr Vescovo — who pioneered the expedition — said the jellyfish-like creature "does not resemble anything seen before".
Chief scientist for the expedition, Alan Jamieson, said the discovery was a "curve ball" and a truly unexpected find during the expedition, news.com.au reports.
"I normally have a pretty fair idea of what we're going to see — but every now and again you get thrown this curve ball," Dr Jamieson told CNN Travel.
"It really looks artificial — it rolls out the darkness and suddenly it turns and you're like, 'Jesus, that's some kind of weird jellyfish.'
"We came to a conclusion it's called a tunicate, which is a sea squirt. This particular one is called, we think, an ascidian," he explains.
"It doesn't really have a common name, because we're not quite sure what it is. But it looks like it's a tunicate which would normally be anchored to the sea floor — using that big long tentacle, it would naturally be physically anchored. And it's for some reason raising its body above the sea floor so it can filter food out the water."
The Indian Ocean trip is the third time the Five Deeps Expedition has successfully dived to the previously-unvisited bottom of one of the world's five oceans.
The dive to the Java Trench, which is measured at 7192 metres deep, is the first human to dive to its depths in the DSV Limiting Factor (Triton 36000/2 model submersible) the world's deepest diving, currently operational submarine.
According to a release on the expedition, the team managed to capture footage from the sub and from the landers of what are believed to be entirely new species, yet unseen by humans.
From the submarine, a new species of hadal snailfish was observed among many other bottom dwelling organisms.
Dr Jamieson said the "rare and unique observations" were a "really significant moment".
"It is not often we see something that is so extraordinary that it leaves us speechless," he said. "At this point we are not entirely sure what species it was, but we will find out in due course."
The Five Deeps Expedition is the first oceanic journey to take a manned, commercially certified submersible vessel further and deeper than any in history. In addition to Vescovo's solo dive, the expedition also accomplished:
• First descent to the bottom of the Indian Ocean
• The most solo dives — three — deeper than 7000m have now been made by a single individual, Victor Vescovo
• First manned descent of any significant depth (below 2000 meters) in the Java Trench and the first descent to the absolute bottom of the trench (7192m)
• Deepest dive by a British citizen (Scottish) in that country's history, by Dr Alan Jamieson to 7180 meters, and first to visit a hadal zone.
• First seabed lander operations including biological sampling and depth confirmation at the bottom of the Diamantina Fracture Zone in the Indian Ocean, 1287 km west of the Australian coast
• Discovered at least four new species of life, including one significantly-sized, stalked Ascidean, previously unseen by any member of the expedition science team
• Completed the third dive of the Five Deeps Expedition and thus 60 per cent complete with the overall mission, and remaining on schedule for completion in September 2019
The mission to the Java Trench aimed to accomplish two goals.
Firstly, it aimed to generate very strong evidence to conclude that this location was not the deepest place in the Indian Ocean (as several geographic sources suggest) and secondly, to provide the first biological samples from the deepest location in this area to add greater scientific insight into its unique biology.