The research, published in Nature Scientific Reports, involved the study of a female king cobra that was caught when she was not yet sexually mature. What was certain was that this snake had never mated with a male cobra. In captivity, she laid twenty-four eggs, which the scientists placed in incubators. Two eggs hatched, both of which were males. After hatching, the young snakes were found to have deformities on their skeleton. Unfortunately, the two males did not survive; both died after two days.
The researchers carried out DNA tests, which revealed that this was a specific case of asexual reproduction: automixis with terminal fusion. Freek Vonk explained the researchers’ findings in an interview with the radio programme Vroege Vogels (‘Early Birds’). “During this process, as the eggs mature in the female’s body, the genetic material in the chromosomes is rearranged and merged in such a way that the self-fertilized eggs will always produce males."
Asexual reproduction, or parthenogenesis, occurs in various animal species, including insects, fish and some other reptiles. But until recently, nobody knew that the king cobra could do it too. This impressive venomous snake does it through facultative parthenogenesis, in which an animal can reproduce either sexually or asexually.
“It is actually an extreme form of inbreeding,” says Vonk. “In the long term this is obviously not beneficial, but in the short term it is a wonderful evolutionary solution to be able to reproduce in an environment without males.” It is therefore not surprising that most cases of parthenogenesis have been discovered in animals living in unnatural conditions, such as in zoos or in people’s homes.