Scientists film deepest-ever fish swimming 8 km underwater in Japan

Scientists have captured footage of a deepest-ever fish swimming more than 8 km underwater, the Guardian reported. The fish has managed to earn a new record for the deepest fish ever recorded. The animal or fish, an unknown snailfish species belonging to the genus Pseudoliparis, has been filmed at a depth of 8,336 metres in the Izu-Ogasawara trench, southeast of Japan. The video has been recorded from an autonomous deep ocean vessel as part of a two-month expedition that began last year. Taking to Twitter, the University of Western Australia (UWA) wrote: "Scientists from #UWA and Japan have set a new record for the deepest fish ever filmed and caught! 🐟 They discovered a snailfish at a depth of 8,336m in the Izu-Ogasawara Trench and caught two more from 8,022m during a two-month expedition."

A deepest-ever fish study by Minderoo-University of Western Australia

After scientists discovered the deepest-ever fish, snailfish, they found two more snailfish of the species Pseudoliparis belyaevi, in the Japan trench from a depth of 8,022 metres. According to the scientists, these would be the first fish to have ever been collected from a depth greater than 8,000 metres. In this expedition project, scientists from the Minderoo-University of Western Australia Deep Sea Research Centre and the Tokyo University of Marine Science and Technology participated in the exploration. The expedition project took place in Japan, Izu-Ogasawara and Ryukyu trenches – which are 8,000, 9,300 and 7,300 metres deep respectively. The study focuses on the decade-long study of the deepest fish populations in the world. To conduct the study, researchers deployed baited cameras in the deepest part of these trenches and used an unmanned submersible known as a lander.  Over 400 species of snailfish can be found in a wide variety of habitats ranging from shallow waters to the darkness of the deep ocean. According to the expedition’s chief scientist and founder of the Minderoo-UWA Deep Sea Research Centre, Prof Alan Jamieson said "specific adaptations enabled some snailfish species to live about 1,000 metres deeper than the next deep-sea fish". Further, the chief scientist explained the experiment briefly and shared that the pressure is 800 times greater than at the ocean surface at 8,000 metres underwaters.

“When you picture what the deepest fish in the world should look like, the chances are it’s gnarly, black, with big teeth and small eyes,” said Jamieson in the press release. Further, he added: "Chances are it’s got nothing to do with deep sea – that has to do with being dark.” He also shared that deep-sea "adaptations" are visible very less, he said: "One of the reasons [snailfish] are so successful is they don’t have swim bladders. Trying to maintain a gas cavity is very difficult at high pressure.” Jamieson has shared that Snailfish do not have scales, but rather have a gelatinous layer described as a “physiologically inexpensive adaptation”. The deepest sea creature caught on film has been understood as a juvenile fish, as per the chief scientist's statement.