The ‘ghost shark’ is so rarely seen in the wild that seeing one is almost like seeing a ghost.
Yet a team of scientists not only spied a never-before-seen species of the elusive fish, they also dragged it to the surface from nearly half a mile down in the Andaman Sea off the coast of Thailand, near the resort destination of Phuket.
The newly described specimen has black, feathery fins, a tail as sharp as a stick, and giant green eyes nearly a third of the length of its head.
Genetic tests revealed it was a new species, bringing the world’s number of known ghost shark species up from 53 to 54.
This newly identified species of ‘ghost shark’ is 276 mm (10.9 in) long and has eyes that make up almost a third of its head length.
An international team of scientists collected it during a deep-sea expedition on behalf of Thailand’s Ministry of Fisheries and the United Nations’ Food and Agriculture Organization.
They caught it in a trawl net dragged along the seabed by a boat during an expedition in 2018, where they also caught two other related species.
Their depth measurements showed that it was between 772 and 775 meters down when it was caught (2,533 to 2,543 feet), nearly half a mile.
When they initially examined it, the team misidentified the 11-inch-long fish as a known species of ghost shark, the chimera. Chimaera aff. macrospina.
But after closer examination, including genetic testing, they have now concluded that it is actually a new species: Chimaera Supapaenamed after fish scientist Supap Monkolprasit.
Monkolprasit was a Thai ichthyologist who devoted her life to studying cartilaginous fish like ghost sharks until her death in 2013.
Although the creature is called a ‘shark’, it is not in the same group as the giant apex predator.
This ghost shark belongs to the order of fish called Chimaeraso named because its members often look as if they have been stitched together from parts of other fish—like the mythical Greek beast that was part lion, part goat, and part dragon.
Genetic testing helped reveal the fact that scientists were actually looking at a new species of ghost shark.
Samples from the specimen were sequenced and then compared to genetic sequences from eight other ghost hair species, including five that lived in the region.
It was a difficult task, because the deep-sea fish’s DNA had begun to degrade after the researchers had raised it to the surface.
These tentacles belong to a species of ghost shark relative called Neoharriotta pinnata. Hidden near their pectoral fins, the spiny organs are used to hold a female in place during mating.
Members of the ghost shark family have been found as much as four feet long, but scientists suspect they can grow up to six in some cases
But they got enough, and when they compared over 1,000 base pairs of DNA to the other sharks’ sequences, it was clearly not a match.
Based on their investigations, they determined that this is an immature man.
Now that they’ve identified it, the researchers can describe how it differs from other ghost hairs: ‘massive head with a short snout’, oval eyes that make up 32.2 percent of its head length, and ‘deciduous skin’.
Interestingly, deciduous skin that flakes off easily has evolved in prey species such as mackerel to help them slip from the grasp of predators.
So maybe the new ghost fish has some bigger deep sea predators.
Male chimeras in particular have genitalia on top of their heads – a structure called a tentaculum.
This, along with two others hidden near their pectoral fins, are used to hold a female in place during mating.
Because they often live around deep-sea continental slopes and ocean ridges, ghost sharks can be caught by bottom trawls.
The darkest depths of the ocean hold many secrets, and the more scientists explore, the more they realize how much they have yet to discover.
“Evolutionarily, these chimeras are among some of the oldest lineages of fish with lineages dating back 300-400 million years,” lead study author David Elbert, program director of the Pacific Shark Research Center at San Jose State University in California, told Live Science.
“The discovery of new species like this chimera tells us how little we know about the marine environment and how much remains to be explored.”
The team published its findings in the journal Raffles Bulletin of Zoology.