Two-Headed Sharks Kept On Popping Up. The Reason? Find Out Here

Scentists say that two-headed sharks may sound like a figment of the big screen, but they exist and more are turning up worldwide.

Now, researchers have identified an embryo of an Atlantic saw tail catshark with two heads. While raising sharks for human-health research in the laboratory, they noticed the unusual embryo in a see-through shark egg. 

 Researchers opened the egg to study the specimen, and study leader Valentín Sans-Coma says it's unknown whether the deformed animal would have survived. Because it's the first such conjoined twin found in egg-laying sharks, its likely that such offspring don't live long enough for people to find them.

 Since the embryos were grown in a lab among nearly 800 specimens, a genetic disorder seems to be plausible cause for the two-headed shark. To the best of their knowledge, the eggs were not exposed to any infections, chemicals or radiation.

But wild sharks' malformations could come from variety of factors including viral infections, metabolic disorders, pollution or dwindling gene pool due to overfishing, which leads to inbreeding and thus genetic abnormalities.

Source: NationalGeographic