King cobra is actually four species
The imposing king cobra (Ophiophagus hannah) is the world’s biggest venomous snake and can measure over five meters long. It inhabits a sizable kingdom across the Asian tropics, stretching from Indonesia to India. However, new research reveals that the king cobra’s massive domain is not ruled by just one species… rather there are four distinct species of king cobra. The four proposed species, which are yet to be officially named, are the Western Ghats lineage in southwestern India, the Indo-chinese lineage in Indonesia and western China, the Indo-malayan lineage spanning
India and Malaysia and the Luzon Island lineage, found in the Philippines.
Despite their similarities, the cobras found in this vast geographic range have some physical differences. For example, adult cobras in Thailand have roughly 70 bright, off-white ring markings on their bodies, while cobras in the Philippines only have a few dull rings. The snakes demonstrate regional differences in their behaviours, too. The king cobra is the only snake species to gather material and build nests for its eggs, but the eggs in that nest might be treated differently depending on the region. In some regions the mother slithers off after laying the eggs, while in other places she might incubate them in the same way a bird would. But it’s not just physical and behavioural differences that separate these four lineages; researchers needed to know if the king cobra populations were genetically different. Gathering such data on the world’s biggest venomous snake was a challenging task. Biologist P. Gowri Shankar, a king cobra expert at the Kālinga Centre for Rainforest Ecology in Karnataka, India, spent years studying these snakes.
Eventually, Shankar and his team have been able to gather enough genetic material to analyse DNA from 62 king cobra specimens found throughout the ranges of the population variants. Researchers gathered scales from live snakes and collected muscle tissue from dead snakes that were discovered as roadkill. They even managed to recover DNA from long-dead museum specimens.
Initially, researchers looked at mitochondrial genes, which are passed from mother to offspring, and they identified four distinct lineages. They then looked at differences in nuclear DNA between the four candidate lineages. It was discovered that the four lineages were not regional variants of one species, but were instead genetically separate from one another. “The overlap of genetic diversity with separate geographic regions suggests the species have been evolving separately without any gene flow between them,” Shankar said.