I hereby give you all permission to freak the hell out. Apparently, the world has a mutant two-headed shark problem.

That’s right: two-headed mutant sharks have been popping up in increasing numbers since way back in 2008 – when fisherman Christopher Johnson caught a pregnant blue shark off the coast of Australia and cut it open to reveal a two-headed fetus that later died, despite his trying to feed it – and scientists still can’t pinpoint exactly what the hell is going on.

This is partly due to the fact sightings are few and far between, making it difficult for researchers to pin down exactly what triggers the mythical mutation.

That being said, Spanish scientists did very recently identify a two-headed Atlantic sawtail catshark embryo – one of the first known specimens from an oviparous shark species, or a shark that lays eggs.

As the resulting study states: “Each head had a mouth, two eyes, a brain, a notochord [like a spinal cord], and five gill openings on each side.”

Shared intestines, kidneys, and reproductive system were also discovered though, because researchers had to open the egg to test it, it’s still unclear whether it would have survived gestation.

The most popular theory for their appearances in the wild, according to the National Geographic, is “viral infections, metabolic disorders, pollution, or a dwindling gene pool due to overfishing”. Our hunch? Nuclear runoff from a power plant.

People are divided into two camps when it comes to these seafaring mutants: the fors, and the againsts (see below):

We have no issue with their existence, so long as the don’t sprout legs and come searching for food on land.

Source: National Geographic.

Photo: Christopher Johnson.