In a first-of-its-kind case, a crocodile at a zoo in Costa Rica has made herself pregnant. The croc produced a foetus that was 99.9% genetically identical to herself, reported the BBC. The phenomenon of so-called "virgin birth" has been found in species of birds, fish and other reptiles, but never before in crocodiles. Scientists believe the trait may have been inherited from an evolutionary ancestor, so say that dinosaurs might also have been capable of self-reproduction.
The egg was laid by an 18-year-old female American crocodile in Parque Reptilania in January 2018. The foetus inside was fully formed but still born and so did not hatch, the media house reported.
The crocodile was two years old when she was taken and kept away from other crocodiles for its entire life. But when the croc got pregnant the entire staff was surprised and decided to contact a scientific team from Virginia Polytechnic that deals in specialised virgin births.
After analysing the birth, the scientists confirmed that the foetus was more than 99.9 percent genetically identical to its mother and confirmed that it had no father, reported BBC.
This kind of a pregnancy is also known as parthenogenesis in scientific terms.
Writing in the Royal Society journal Biology Letters, the researchers said: “It is not uncommon for captive reptiles to lay clutches of eggs, given the period of isolation from mates, these would normally be considered non-viable and discarded. These findings therefore suggest that eggs should be assessed for potential viability when males are absent.
“Furthermore, given that (virgin births) can occur in the presence of potential mates, instances of this may be missed when reproduction occurs in females co-habited with males”.
It is unclear why parthenogenesis occurs in different species, but occurrences are cropping up in the scientific literature more often, probably because researchers are now looking for it, the BBC said in its report.