A fisherman working off the Florida Keys coast was recently stunned to find live fetuses inside a bull shark he caught. What made the catch even more surprising was when one fetus was found to have two heads!
The fisherman gave the shark fetus to scientists led by by C. Michael Wagner of Michigan State University. He and the team wrote on the unusual shark in a report published in the Journal of Fish Biology this week.
The scientist wrote that this was a very rare occurrence and it was the first time that a bull shark was found to have two heads. He also added that in recorded history there are only 6 cases of sharks with double heads known.
“In and of itself, this single natural history observation does not tells us anything Earth-shattering about the health of the world’s oceans or populations of bull sharks,” Wagner said.
“It’s simply a rarely observed phenomena that we recorded. Yet, it does capture public attention, and what a great opportunity for journalists like yourself to shine the light on some interesting information that does bear on that very important question.”
The two heads as the expert explains is because of a phenomena that is found in other animals and also humans sometimes. The process is technically called “axial bifurcation,” in which the embryo doesn’t finish splitting into two separate individuals. It is a kind of mutation.
In the natural world the scientist says it is difficult for such animals to survive as it is challenging for them to hunt and avoid predators. The two headed bull shark fetus they observed also came with a very small body as most bulk was carried by the two heads.
The fisherman who caught the shark said that the fetus died shortly after the mother was caught.
“It likely would not have survived very long had it been born naturally,” said Wagner.
He added though that such unique organisms provide interesting study material for them and help understand the development process in a better way.