Scientists have documented the first known case of a ‘virgin birth’ from a crocodilewho was wearing 16 years living isolated in a zoo in Costa Ricaaccording to a study published this Wednesday.
The American crocodile female laid 14 eggs in 2018 inside her enclosure, a not uncommon phenomenon among captive reptiles. The most puzzling development, however, occurred after three months of incubation, when one of the eggs was discovered to contain a fully formed baby crocodile that had been born stillborn.
The scientists analyzed the genetic makeup of the crocodile fetus, according to the study published in the journal ‘Biology Letters‘. They found DNA sequences showing that it was the result of facultative parthenogenesis (PF), or reproduction without the genetic contribution of males.
The phenomenon of PF, which some scientists have referred to by the abbreviation “virgin birth,” has also been documented in other species of fish, birds, lizards, and snakes. According to scientists, this is the first known example in a crocodile.
in the PF, a female’s egg can develop into a baby without being fertilized by the sperm of a male.
To make an egg, a precursor cell divides into four cells: one becomes the egg and retains key cell structures and gelatinous cytoplasm, while the others contain additional genetic material.
In danger of extinction
One of those cells then essentially acts as a sperm cell and fuses with the egg to become “fertilized.”
The American crocodile is considered vulnerable and endangered in the wild. One hypothesis is that PF may be more common among species on the brink of extinction, the study notes.
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The scientists claimed that the “virgin birth” of Costa Rica could provide new information about the ancestors of crocodiles that walked the Earth in the Triassic Period, about 250 million years ago.
“This discovery offers a tantalizing glimpse of the possible reproductive abilities of the extinct archosaur relatives of crocodiles and birds, particularly members of the Pterosauria and Dinosauria,” the study notes.