Amazing: The first case of a crocodile that fertilized itself, the fetus was 99,9% identical to her
The first case of a female crocodile impregnating herself has been identified at a zoo in Costa Rica. She gave birth to a fetus that was 99,9% genetically identical to her. Such a phenomenon has been found in several species of birds, fish and other reptiles, but never before in crocodiles.BBC".
Scientists say this trait may have been inherited from an evolutionary ancestor, so dinosaurs may have been capable of self-reproduction.
The egg was laid by an 18-year-old female crocodile at Reptilania Park in January 2018. The fetus inside was fully formed, but stillborn and therefore not hatched.
The animal was obtained when she was two years old and was separated from other crocodiles all her life. Because of this, the park's scientific team contacted an American team from Virginia Polytechnic University, specialized in this phenomenon, which is scientifically known as parthenogenesis. They analyzed the fetus and found that it was more than 99,9% genetically identical to its mother – confirming that there was no father.
Writing in the journal Biology Letters, the researchers say such cases may be more common in crocodiles and have gone unnoticed until now because people haven't looked for such examples.
"It is not uncommon for captive reptiles to lay eggs that, given the period of isolation from their mates, would normally be considered unviable and discarded. Therefore, these findings suggest that eggs should be assessed for potential viability when males are absent. "Given that such events can occur in the presence of potential mates, examples of this may be missed when reproduction occurs in females cohabiting with males," the scientists said in their research paper.
It is not clear why parthenogenesis occurs in different species, but the phenomenon is appearing more frequently in the scientific literature, probably because researchers are now looking for it. One theory is that this happens in species capable of parthenogenesis when numbers dwindle and they are on the brink of extinction.
"This new evidence offers compelling insights into the possible reproductive capabilities of extinct crocodilian relatives," the scientists write, "especially dinosaurs."
