A new study has revealed that the world’s longest venomous snake, the king cobra, is not a single species, as previously thought, but rather four genetically distinct species. Led by wildlife biologist P Gowri Shankar, the research involved collaboration between scientists from the UK, Sweden, Malaysia, and India.
The study challenges the long-held belief that, despite visual differences in king cobras across their wide geographic range, they all belong to the same species, Ophiophagus hannah.
King cobra was first described by Danish researcher Theodore Edward Cantor, in 1836 as Hamadryas hannah. In the following year, another species from South East Asia’s Sunda region, was proposed by Hermann Schlegel as Naja bungarus which was later renamed after validation in 2024 as Ophiophagus bungarus.
From 1836, till as late as 1961, many scientists tried unsuccessfully to classify king cobra. Following confusion regarding the species distinction, it was later decided, in 1945, that the king cobra was a monotypic species (with no sub-species), and was named Ophiophagus hannah, explains Gowri Shankar.
Now, after 185 years of uncertainty around its taxonomy, the new study finds both genetic and morphological evidence to prove there is not one, but four distinct species of king cobras, two of which have been named for the first time by the team.
The king cobra is widely distributed across the tropical forests of South and Southeast Asia, spanning from India to the Philippines. The four species are: O. hannah (Northern king cobra), O. bungarus (Sunda king cobra), O. kaalinga (Western Ghats king cobra), and O. salvatana (Luzon king cobra). The Northern king cobra (O. hannah) is found across eastern Pakistan, northern and eastern India, the Andaman Islands, Indo-Burma, Indo-China, and Thailand. O. bungarus is native to the Sunda Shelf area, while O. kaalinga and O. salvatana, the newly named species, are located in the Western Ghats and on Luzon in the northern Philippines, respectively.
“I always suspected it was more than one species because they look and behave very differently from each other,” says wildlife biologist Romulus Whitaker, who has studied king cobras in the Western Ghats for an extended period. He explains that studies involving genetic data can take time due to various factors, including obtaining permits and collecting samples. “Meticulous research is required to produce reliable results,” he adds.
Whitaker notes that recent advances in genetic tools have been a significant advantage. “Since we published the snake field guide (Snakes of India: The Field Guide) in 2004, more than 40 new species have been described. For instance, the common vine snake is now recognised as seven distinct species. This progress is possible thanks to the new technology and tools available for species research,” he explains.
In total, 153 (148 non-skeletal, five skeletal) specimens were examined, as part of this study, to conclude that on a genetic level the species differed about 1%-4% from each other. This is significant, according to Gowri Shankar, who puts the number into perspective – humans are genetically only 1% percent different from chimpanzees.
Gowri Shankar points out that while the study was able to clearly distinguish the four species, there may be more species yet to be described. “King cobras could potentially be five or six species. More research is needed,” he says.
One of the most significant morphological traits distinguishing the species, as highlighted in the paper, is the number of dorsal bands. “Adults from the Luzon population, unlike juveniles, do not exhibit any distinct pale bands. In adult O. salvatana, the bands are faint and barely discernible, giving them a mottled, nearly unbanded appearance,” the paper notes.
“O. kaalinga has three to four rows of dark scales between each white band,” explains Gowri Shankar, using photos for reference. “In the case of O.hannah, the white scales on the band have black borders.” He adds that O. bungarus, on the other hand, has multiple light-coloured bands. “If we count the bands, O. kaalinga has fewer than 40 bands, O. hannah has between 40 and 70 bands, and O. bungarus has more than 70 bands. The juveniles of O. bungarus can have between 100 and 135 bands,” Gowri Shankar notes.
The latest findings have significant implications for the conservation of king cobras, say experts. The species is currently listed as vulnerable on the IUCN Red List of threatened species. Until now, the king cobra was considered a commonly found species with a wide distribution, and it was thought not to require special protection. However, this view has shifted with the recent findings.
Of the four newly described species, O. kaalinga and O. salvatana are highly endangered and now warrant special conservation status, according to Gowri Shankar. He notes that the Philippine government and authorities in Luzon have taken cognisance of these findings and are considering measures to protect the species, which may include cracking down on poaching, illegal exports, and other threats to the animal.
Whitaker notes that the king cobra (O. kaalinga) is revered and worshipped in the Western Ghats, which has historically contributed to its conservation. However, this cultural respect is no longer sufficient, as nearly 80% of the forests in the region have either disappeared or are under severe stress. He emphasises that educating local communities is also crucial for the species’ conservation. The king cobra is not only visually imposing but also plays many vital ecological roles, including controlling the population of medically significant snakes such as the spectacled cobra (Naja naja) since they prey on other snakes.
Another important implication of the study’s findings is for antivenom research. Despite the high potency of king cobra venom, India does not have a specific antivenom for its bite, likely because king cobra bites and fatalities are rare in the country, and the species is not one of the “Big Four” medically significant snakes.
However, with the recent discovery of multiple distinct species, the only available antivenom – the Thai Red Cross Society’s Ophiophagus hannah Monovalent Antivenom (OhMAV) – is effective only against O. hannah envenoming and may not work for bites from other king cobra species. “This antivenom may be effective in the eastern parts of India, but it certainly won’t work in the Western Ghats,” says Gowri Shankar.
Whitaker emphasises the need to develop a specific antivenom for king cobra bites, as neither the polyvalent antivenom used in India nor the Thai antivenom neutralises king cobra venom effectively in the country. While king cobra bites are rare, he points out that an antivenom is crucial for the protection of snake handlers, zookeepers, researchers, and others who work closely with the species.
Gowri Shankar adds that an antivenom could help alleviate public fear of the animal and its venom, potentially reducing hostility towards it. This, in turn, could aid in the conservation of the species. Most importantly, Gowri Shankar stresses that authorities must take proactive steps in habitat protection to prevent the endangerment of this magnificent snake.
This article was first published on Mongabay.