First discovery of parthenogenetic crocodiles.

Costa Rica: An American alligator living alone in a reptile park enclosure for 16 years laid a clutch of 14 eggs, surprising zoo staff.

The American alligator living in Parque Reptilandia has never mated. Photo: Alamy

Scientists have for the first time documented a case of a crocodile "parthenogenesis." The female crocodile, who lived in isolation for 16 years, was discovered with a clutch of eggs, revealing the evolutionary origins of this reproductive behavior. The American crocodile ( Crocodylus acutus ) was captured at the age of two and lived in an enclosure at Parque Reptilandia reptile park in Costa Rica. It remained there alone for the next 16 years. However, in January 2018, authorities found a clutch of 14 eggs in its enclosure.

Parthenogenesis is a form of asexual reproduction in species that are normally capable of sexual reproduction. Scientists have documented asexual reproduction in birds, sharks, lizards, and captive snakes, among many other species. However, they had never previously encountered such behavior in the crocodile family, including the common crocodile, alligator croaker, caiman, and Ganges crocodile.

In a study published on June 7 in the journal Biology Letters, the authors reported that seven of the fourteen eggs laid by a crocodile in Costa Rica were viable. Zoo staff incubated the eggs, but they did not hatch. They opened the eggs. The contents of six of them were not clearly visible, but the remaining egg contained a fully formed embryo. Genetic analysis showed it was almost identical to the mother.

The research team, led by Warren Booth, an entomologist at Virginia Tech, said they were somewhat disappointed that the egg failed to hatch. However, it's not uncommon for offspring born this way to be deformed and unable to develop. They believe parthenogenesis may be more common in endangered species.

The discovery of parthenogenesis in crocodiles means that this form of reproduction is also present in birds, descendants of dinosaurs and crocodiles, demonstrating a common evolutionary origin. Birds and crocodiles are surviving representatives of the clerical lizards, a group of animals that includes both dinosaurs and flying lizards.

An Khang (According to Live Science )

Source link: https://vnexpress.net/lan-dau-phat-hien-ca-sau-trinh-san-4614484.html