Sign up for Guardian Australia’s free morning and afternoon email newsletters for your daily news roundupĪt 8,000 metres underwater, the pressure is 800 times greater than at the ocean surface. 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. There are more than 400 known species of snailfish, which live in a wide variety of habitats ranging from shallow waters to the darkness of the deep ocean. Using unmanned submersibles known as landers, researchers deployed baited cameras in the deepest part of these trenches. Figuring out how this eclectic bunch interacts “is part of the fun.Scientists from the Minderoo-University of Western Australia Deep Sea Research Centre and the Tokyo University of Marine Science and Technology had set out to explore the Japan, Izu-Ogasawara and Ryukyu trenches – which are 8,000, 9,300 and 7,300 metres deep respectively – as part of a decade-long study into the deepest fish populations in the world. Jacó Scar is a “mixing bowl” of species found in other parts of the world, Seid says. The eelpout is part of a medley of other species that form Jacó Scar’s composite ecosystem, along with, for example, clams typically found at cold seeps and bacteria found at hydrothermal vents. jaco to its vent-living relatives, researchers may be able to figure out how it adapted to live in the tepid waters of the Scar - which may provide clues to how other species living there did too. It may have to do with the fact that methane seeps are more common than previously thought on the ocean floor, and if some are lukewarm like Jacó Scar, the new species could have used them as refuges while moving east.Īnd by comparing P. The new finding raises questions about how the known Pyrolycus species came to live so far apart. A Pyrolycus jaco specimen is shown freshly collected (top), preserved (middle) and in X-rays superimposed over the fresh image (bottom). Of the 24 known fish species that live only at hydrothermal vents, “13 of them are eelpouts,” Frable says. The first eelpouts most likely evolved in cold waters, Frable says, but many have since made their home in the scalding waters of hydrothermal vents.
“I did not know that genus existed,” Frable says.īecause the other two known Pyrolycus species live far away in the western Pacific and have different physical features, the team dubbed the mystery fish P. Møller narrowed the enigmatic eelpout to the genus Pyrolycus, meaning “fire wolf.” Turns out, the tool, called a dichotomous key, that Frable had been using to identify the specimens was outdated, made before Pyrolycus was described in 2002. “I just was not really getting anywhere.” So the team turned to eelpout expert Peter Rask Møller of the Natural History Museum of Denmark in Copenhagen, sending him X-rays, pictures and eventually one of the fish specimens. Eelpouts are a diverse family of fish comprised of nearly 300 species that can be found all over the world at various ocean depths.īecause the physical differences between species can be subtle, they are “kind of a tricky group” to identify, Frable says. But he was having trouble determining what type. They look exactly as one would expect based on their name: like frowning eels, though they aren’t true eels. Charlotte Seid, an invertebrate biologist at Scripps who is working on a checklist of organisms found at the Costa Rican seeps, brought the fishy finds to ichthyologist Ben Frable, also of Scripps, for formal identification.įrable says he knew the fish was an eelpout. Several more specimens were snagged during later submersible dives. She recalls the team finding and collecting one of the fish during this early excursion, but the researchers didn’t recognize it as a new species.
Levin was on one of the first expeditions to the Scar but wasn’t involved in the new study. It is “a really diverse place” with many different organisms living in various microhabitats, says Lisa Levin, a marine ecologist at Scripps Institution of Oceanography in La Jolla, Calif. Jacó Scar was discovered during exploration of a known field of methane seeps off the Costa Rican coast and named for the nearby town of Jacó.
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