Two-headed sharks are becoming more common than would be expected without science have a clear reason to explain this phenomenon, seen primarily in fetuses or embryos that fail to live.
The last case was documented by Spanish researchers, who detected one of these specimens while developing sharks in a laboratory for testing related to human health. Specifically, it is a nurse shark (or “nurse shark”), identified through the transparent eggs of this species.
The finding is particularly important because it is the first discovery of a two-headed shark in a kind where the shark is played through eggs.
According to National Geographic appropriated, the new discovery to other sharks two heads found in 2008, 2011 and 2013 copies of blue sharks, all fetuses or embryos adds. The publication indicates that this species is the one that produces this type of deformation, because it also takes a lot of baby inside: up to 50 simultaneously.
What causes these malformations? So far there is no clear explanation, although they have ruled out some theories. For example, Valentin Sans-Coma, cars studio cat shark, indicates that you can rule out infection, chemical or radiation exposure as a possible option, as in his laboratory specimens were not exposed to these characteristics.
So, Sans-Coma says the most likely explanation is a genetic disorder that could be caused by various reasons, including metabolic problems, pollution or decrease in the gene pool of these animals affected by the high level of fishing. This would lead to inbreeding, causing genetic abnormalities.
Another explanation presented by Javier Galvan-Magana (author of the study concerning the case of 2011), is that these cases are not increasing in frequency but there is now more attention and scientific journals for display. Anyway, he says, studying is not easy because either these specimens are still rare and hard to find.
