SALT LAKE CITY — What's more terrifying than a shark? Maybe the two-headed shark a fisherman found on the Gulf of Mexico.
The fisherman caught a female bull shark on April 7, 2011, discovering she was carrying a two-headed shark fetus. Scientists confirmed in the March Journal of Fish Biology that it was a single shark with two heads rather than conjoined twins.
The occurrence of a two-headed shark is rare, but researchers say this is the first they have found among bull sharks. Through MRI scans, scientists found the animal had two hearts and stomachs to accompany its two heads, though it had a single tail.
The phenomena is interesting, but also detrimental to a predator in the ocean, researchers said. The animal's speed and ability to catch other fish would have been lessened by its condition.
The small body, its growth stunted by two well-developed heads, also put the animal at a disadvantage in the wild, researchers said.
Deformities like this are common with breeders, who can sell the deformed animals for a hefty price, but in the wild, it's much more rare.
"This is certainly one of those interesting and rarely detected phenomena," Wagner said. "It's good that we have this documented as part of the world's natural history, but we'd certainly have to find many more before we could draw any conclusions about what caused this."