Strange findings - sharks give birth to babies without a father

Female sharks can fertilize their own eggs and give birth without male sperm, a new study of the reproductive sex of a hammer shark in the US said.

Research cooperation between the US and Northern Ireland, analyzed the DNA of a shark born in 2001 in the Henry Doorly zoo in Omaha, Nebraska. This animal was born in a tank with only 3 potential mothers, none of whom had ever been exposed to a male hammer shark for at least 3 years.

The fry was killed by a stingray stingray that lived with the tank just hours after its birth. Analysis of its DNA does not find any trace of chromosomes from another male.

Shark experts say this is the first case confirmed to be a single reproduction in sharks - the term comes from Greek meaning "reproduce virginity".

(Photo: Honoluluadvertise) tSimilar reproduction is common in insects, rarer in fish and reptiles, and almost never recorded in mammals. The list of species known to be more and more long-lasting, especially those in captivity, but until now, sharks have never been considered a potential candidate.

"This discovery is really amazing because as far as everyone knows, all sharks breed in a bisexual manner, meaning that there is a combination of a male and a female. Embryos The DNA of both newly developed parents must be obtained, like mammals, " said biologist Paulo Prodohl of Queen's University in Belfast, Northern Ireland, co-author of the study.

"According to scientific habits, we doubted our results and did it again and again, the third time using a new technology with a new genetic approach. This time confirming that no male DNA was available. Prodohl said.

Before this study, many experts still believe that a female can store male sperm in her body for months. This may sound most reliable even though the sharks have arrived in the zoo in Nebraska when they were immature.

However, the absence of his father's DNA in the baby shark eliminated that possibility.

According to an expert, the finding also helps explain the growing number of anecdotal reports of unmarried shark births in captive farms.

T. An