A group of American scientists have documented the first case of a female crocodile being able to reproduce without the participation of a male. The milestone has been carried out by an American crocodile (Crocodylus acutus) that had been alone in an enclosure in the Reptilandia Park in Costa Rica for 16 years before laying eggs.
Previous research had found cases of facultative parthenogenesis (FP), a type of asexual reproduction, in birds, non-avian reptiles, specifically lizards, or snakes, but never before in Crocodilia, a group that includes gharials, alligators, alligators, and crocodiles.
“The data supports terminal fusion automixing as a reproductive mechanism; a finding that suggests a common evolutionary origin of FP in reptiles, crocodiles and birdsâ€, points out this team of entomologists and specialists in reptiles from the Polytechnic Institute and Virginia State University, among other participating entities.
This female American crocodile, a species considered endangered by the International Union for Conservation of Nature (IUCN), was located when she was two years old (2002) and remained isolated from other crocodiles throughout her life. On January 17, 2018, a clutch of 14 eggs was discovered in the enclosure of Parque Reptilandia (Costa Rica).
According to the research, published in Biology Letters, of the 14 eggs laid, seven appeared to be fertile and were artificially incubated. After three months of incubation, the eggs failed to hatch and were opened to assess their content.
And here came the surprise: “The contents of six eggs could not be discerned, but one egg was found to contain a fully formed, non-viable fetus.” In this case, a genetic study of the most advanced specimen revealed that it was almost identical to its mother.
In the opinion of the scientists, this discovery “offers tantalizing information about the possible reproductive capacities of the extinct archosaur relatives of crocodiles and birds, particularly members of the Pterosauria and Dinosauria.”
American crocodiles normally mate to reproduce, like most other reptiles. And they lay eggs that later hatch. But now, it seems that they can reproduce asexually if necessary.
