There is a debate among scientists about whether sharks are capable of immaculate conception. Recent cases confirm that this is possible
"Immaculate Conception" has already been observed in some species of fish, amphibians and even birds. Scientists suspected that it was possible in sharks - and here there are two cases at once. The last incident happened with a blacktip shark, and the previous one with a hammerhead in one of the zoos in Omaha in the United States, the website Membrana.ru says.
A team of biologists have examined the DNA of a pregnant female Atlantic blacktip shark and found no trace of the male's genetic material. The most interesting thing is that this is the second case in recent years.
The unusual incident was reported in the Journal of Fish Biology.
The story of immaculate conception began 16 months ago when a shark named Tidbit died at the Virginia Aquarium. All eight years that she was in captivity, she did not have meetings with males of her species.
An autopsy revealed that the large fish was pregnant - a cub, approximately 25 centimeters long, was found in its womb.
At first, everyone thought that the female was fertilized by a male of a different species - which had never been observed before. However, subsequent DNA analysis showed that we are still talking about same-sex reproduction or parthenogenesis - this is a way of reproduction when eggs develop without fertilization.
In other words, the Tidbit cubs have inherited only one set of chromosomes - from their mother, says the website Membrana.ru.
“This is not a miracle. In theory, this option is provided by nature, and for many species of sharks, - said lead author Damian Chapman of the Pew Oceanographic Institute.
Both females, conceiving independently, bore one cub, while in a number of other cases sharks can bear up to a dozen offspring.
"It is very unlikely that a small number of surviving females will independently produce many offspring," explains Dr. Chapman for such a reproductive anomaly.
Scientists believe that the triggering of the parthenogenesis mechanism can signal negative processes in the ocean in general and in some shark species in particular, Membrana.ru writes.
This point of view, for example, is shared by Mahmoud Shivji of the Oceanographic Center of the New Southeastern University: "Parthenogenesis may be due to the fact that females simply cannot find partners for themselves due to the global decline in their population."