When people first heard of two-headed sharks, they thought that they are only a myth. However, a latest study has revealed that not only these creatures exist on Earth, but they are also increasing in numbers in the oceans.
The presence of two-headed sharks in oceans seem mysterious, however, it is actually happening. Daily Mail Online recently tweeted that these weird sharks are appearing at an alarming rate in the oceans, but no one knows why is this actually happening.
Some fishermen in Florida caught a blue shark a few years ago. That shark had two-headed embryo inside its uterus. After a few years in 2008, another fisherman reported discovering a two-headed shark embryo in the Indian Ocean, according to National Geographic.
The trend observed in the appearance of two-headed embryos show that most of these belong to blue sharks. This is primarily because blue shark are known to carry at may as 50 embryos at the same time, thus increasing their chances of carrying a two-headed embryo.
Despite years of efforts, the researchers are still clueless about the explosion in number of two-headed sharks in the ocean in the recent years. Nicolas Eheman of the National Polytechnic Institute in Mexico believes that this could be due to overfishing or due to shrinking gene pool of the sharks.
Both of the aforementioned condition increases the risk of polycephaly, a rare birth defect that causes the embryo to have two heads attached to a single body. Some other factors that may lead to this condition include pollution, viral infections and metabolic disorders.
A recent study published in the Journal of Fish Biology details on how the researchers discovered an unusual embryo of a tail catshark. The embryo had two heads and that is when the researchers decided to split open the egg.
The researchers claim that this the first specimen of an unusual embryo recovered for an egg-laying shark. In addition, they believe that such conjoined sharks would not survive for long.
