Imagine Jaws through the eyes of director Guillermo del Toro, and maybe you get something like this: a two-headed shark that’d be right at home in something like “Pan’s Labyrinth 2: The Ocean Blue.”
According to the Journal of Fish Biology, where research on the incredibly rare find was published, it’s in fact the only recorded instance of dicephalia — the scientific term for a fetus with two heads — in a bull shark. The shark was discovered inadvertently by a fisherman working in the Gulf of Mexico who caught an adult bull shark on April 7, 2011, then extracted the two-headed fetus after opening the uterus. The shark died shortly after being removed — experts say it stood little chance of surviving had it been born naturally.
Michigan State University — which led the study alongside Florida Keys Community College that eventually confirmed the shark was in fact a single organism and not a set of conjoined twins — noted the reason for its rarity is that creatures born with this sort of abnormality tend to die shortly after birth.
“You’ll see many more cases of two-headed lizards and snakes,” said MSU assistant professor of fisheries and wildlife, Michael Wagner. “That’s because those organisms are often bred in captivity, and the breeders are more likely to observe the anomalies.”
In this case, those anomalies included the axial skeleton and internal organs dividing into parallel systems, including “two well-developed” heads. Yes, you’re forgiven for shuddering at the phrase “two well-developed heads.”
What caused the mutation? It’s all guesswork at this point, but don’t assume it had something to do with the 2010 BP oil drilling catastrophe. According to Wagner, “Given the timing of the shark’s discovery with the Deepwater Horizon oil spill, I could see how some people may want to jump to conclusions … Making that leap is unwarranted. We simply have no evidence to support that cause or any other.”