In an extraordinary occurrence, a crocodile in Costa Rica has achieved a self-induced pregnancy, marking the first recorded instance of a "virgin birth" in the reptile species.
This remarkable event took place while the crocodile was held in captivity within a zoo and had no contact with male crocodiles. Surprisingly, one of her eggs contained a fully-formed foetus. Genetic analysis revealed that the foetus shared 99.9% of its DNA with the mother, providing conclusive evidence of a lack of paternal contribution.
While virgin births, or parthenogenesis, have been documented in various animal species such as birds, lizards, snakes, and fish, this phenomenon has never been observed before in crocodiles.
The particular crocodile in question was 18 years old when she laid a clutch of eggs back in 2018. Out of the seven seemingly viable eggs that were incubated, none successfully hatched. However, upon opening one of the eggs after three months, a stillborn crocodile foetus was discovered.
Researchers from Virginia Tech, specializing in parthenogenesis, conducted an analysis of the foetus, and their findings were published in the prestigious Royal Society journal Biology Letters.
This groundbreaking discovery suggests that virgin births could be occurring in crocodiles without previous recognition. It highlights the importance of assessing egg viability even in the absence of male counterparts, as captive reptiles frequently lay eggs that are considered non-viable and are typically discarded.
Furthermore, the researchers note that instances of virgin births might be overlooked when reproduction occurs among females cohabiting with males, even though such events can happen in the presence of potential mates.
The scientists involved in the study believe that this unprecedented observation provides "tantalizing insights" into the potential reproductive capabilities of extinct crocodile relatives, particularly dinosaurs. The implications of parthenogenesis in crocodiles open up new avenues for understanding the evolutionary aspects of this trait.
