Two headed sharks: Scientists observe increase
THEY may sound like something out of a warped fantasy novel however two-headed sharks are a real thing and scientists across the globe are working towards an explanation of why they're seeing more and more of them.
Interest in the phenomenon has surged in recent weeks after scientists researching the rare and threatened Galeus atlanticus species in a laboratory in Spain noticed one of the 797 embryos they hatched from eggs had two heads.
In a paper published in the Journal of Fish Biology on October 9 the team, which was researching the species described what they believe was the first two-headed Atlantic sawtail catshark.
"Each head had a mouth, two eyes, a brain, a notochord and five gill openings on each side," the team wrote.
"There were two hearts, two oesophaguses, two stomachs, two livers, but a single intestine with a spiral valve."
While this is believed to be the first documented two headed shark to hatch from an egg it is far from the most impressive looking specimen and isn't the first one reported in recent years.
In 2013 a two-headed bull shark was reported again in the Journal of Fish Biology after a fisherman gave one to a marine biologist in the US.
That shark was caught in the Gulf of Mexico near Florida.
In that case the shark had two functioning bodies but didn't survive long.
When that report surfaced it led another man, this time an Australian, to come forward with images and a story about his own brush with the freaky creatures.
In 2008 Christopher Johnston contacted National Geographic and sent in photos of a two-headed Blue Shark he said he caught off a long-lining trawler off the coast of Western Australia.
"We pulled up a pregnant blue shark, cut it open, and there was the two-headed one," Johnston of the discovery. .
"It was about two-thirds the size of the rest of the pups in length. I put it in the tank on the deck. It swam a little while, but it couldn't swim properly, it just swam in one spot as if it were on a treadmill. I tried feeding it squid but it wasn't interested."
Scientific opinion is divided on whether there are actually more two headed sharks appearing or if it is simply a case of more scientists looking at more sharks therefore increasing the likelihood of observing the rare phenomenon.