In a Costa Rican zoo, a virgin crocodile has shocked experts by becoming pregnant on her own.
When the 18-year-old American crocodile lay an egg with a completely grown baby that was 99.9% genetically identical to herself, the finding was made.
Given that the crocodile had been living alone for 16 years without ever mating, it was an amazing discovery. There have been instances of so-called “virgin birth” in some bird, fish, and reptile species, but never in crocodiles. The American crocodile was captured in 2002 at the age of two and housed in a Costa Rican enclosure, where she lived independently for the following 16 years.
Zookeepers found a clutch of 14 eggs in the enclosure in January 2018. While these eggs did not hatch, one of them did contain a completely developed fetus. Although stillborn, the inner fetus was completely developed and did not hatch.
“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,” the scientists say in their research paper.
It continued: “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”.
Genetic analysis of the tissues from the foetus’s heart and from the mother’s shed skin confirmed that the genetic match to the female croc and that the offspring had no father.
