Q COSTA RICA – The BBC and other international news outlets reported on Tuesday that a female American crocodile (cocodrylus acutus) living in Reptilandia Park, between Dominical and Pérez Zeledón, had a ‘virgin birth’ – meaning she reproduced without the help of a male.
“Coquito” has been isolated from other crocodiles since, in captivity since 2022 when she was two years old.
“This crocodile arrived at Reptilandia Park when it was two years old in 2002. She is called ‘Coquito’. She was never with other crocodiles. When she was 18 years old, she laid 14 eggs (January 17, 2018). That’s not unusual, crocodiles can lay infertile eggs, just like chickens. But, of the 14 eggs, seven appeared fertile. After three months of incubation, none of the eggs hatched. They opened the eggs and one had a non-viable, fully formed fetus,” Loyal Clarke, one of the park’s owners, told Teletica.com.
According to the study published in the journal Biology Letters, scientists tested the crocodile’s 99.9% genetically identical fetus’ genetic makeup. They found DNA sequences showing it was a result of facultative parthenogenesis (FP), or reproduction without the genetic contribution of males.
Details about the crocodile’s virgin birth, also called facultative parthenogenesis (FP), were published in the scientific journal Biology Letters on Wednesday.
Scientists do not know for certain why some species are capable of virgin births. Many theorize the ability may come when animals are facing difficult environmental conditions or possible extinction.
Researchers wrote that Coquito may have inherited the ability for asexual reproduction from an evolutionary ancestor. Certain species of birds, fish and reptiles are capable of virgin births, though a case involving a crocodile has never been documented.
In FP, a female’s egg cell can develop into a baby without being fertilized by a male’s sperm cell.
In making an egg cell, a precursor cell divides into four cells, then one of those cells essentially acts as a sperm cell and fuses with the egg to become “fertilized.”
Finding Reveals New Clues About Dinosaurs
The scientists point out that this trait could be inherited from an evolutionary ancestor such as dinosaurs, which, according to this finding, may have had the ability to self-reproduce through parthenogenesis.
“This new evidence offers tantalizing information about the possible reproductive abilities of extinct relatives of crocodiles, especially dinosaurs,” the scientists note.
“This discovery offers tantalizing insights into the possible reproductive capabilities of the extinct archosaurian relatives of crocodilians and birds, notably members of Pterosauria and Dinosauria,” the study said.
It is not yet clear why parthenogenesis occurs, however, experts believe that it could be a survival method for species that are on the brink of extinction.
The American crocodile is considered vulnerable and at risk of extinction in the wild. According to one hypothesis, FP may be more common among species on the verge of extinction, the study said.
Currently, the Reptilandia Park is closed and expects to re-open in December.