The king cobra, the world’s longest venomous snake, is no longer just one species. A new paper by scientists has reclassified the iconic animal into four distinct species from Mainland Asia, most of Maritime Southeast Asia, the Western Ghats of India and the Philippines’ main northern island of Luzon respectively.
A team led by P Gowri Shankar, who has studied king cobras for close to two decades, had conducted an earlier analysis in 2021. They had identified “four geographically separate lineages as confirmed candidate species (CCS)”.
These included an endemic Western Ghats lineage in India, a widespread Asian mainland lineage distributed from northern and eastern India to China and Thailand, a Malesian lineage distributed in the Malay Peninsula and the Greater Sunda Islands as well as part of the Philippines, and an isolated island lineage on Luzon Island, Philippines, noted the study.
“Here, as a follow up to Gowri Shankar et al.’s (2021) study, we present a formal taxonomic revision of the genus Ophiophagus, morphological diagnoses and descriptions of these four lineages, and describe two as new species. Our nomenclatural and taxonomic decisions have extensive implications for the content, diversity and distribution of members of this genus, as well as the management of snakebite, species conservation and prospects for future research,” the scientists wrote.
It was Danish zoologist Theodore Edward Cantor who first gave a taxonomic identity to the king cobra in 1836.
The common scientific name of the species is Ophiophagus hannah. The genus name is Greek, alluding to the snake-eating habits of member(s) of the genus, from the respective roots, ‘ophis’ for ‘snake’ and ‘phagos’ for ‘eater’, write the authors of the present study.
They add that the source of the word ‘hannah’ was not mentioned by Cantor. However, Kraig Adler from Cornell University argued in 2016 that the hannah in Ophiophagus hannah was an eponym for Hannah Sarah Wallich (1820-1893), eldest daughter of Cantor’s host and uncle, the celebrated botanist (and physician), Nathaniel Wallich (1786–1854), during his time in Calcutta, and at the time of description of the species.
Since Cantor’s taxonomical classification, however, no revision has happened. This, despite the fact that scientists have come across extensive variations in the animal throughout its range.
“It seems remarkable that the systematics of the Ophiophagus hannah species complex, comprising the largest venomous snakes of the world, has remained unsettled since 1836,” the authors wrote.
This was partly due to the fact that there has been a scarcity of comparative material at a single institution (that was often the case at the time). “Overlapping squamation characters, traditionally utilized in snake taxonomy, have contributed to obscuring the identities of these species,” the scientists added. ‘Squamation’ refers to scales that reptiles exhibit.
The researchers analysed the systematics of snakes referred to as Ophiophagus hannah through examination of morphological characters in preserved material.
Cantor initially gave the name Hamadryas hannah to the animal after the Hamadryad of Greek myth in 1836 on the basis of four king cobra specimens, three captured in the Sundarbans and one in the vicinity of Kolkata. In 1836, he suggested a revision in the name, calling it Hamadryas ophiophagus. In 1864, British zoologist of German origin Albert Gunther proposed the genus name Ophiophagus, for the cannibalistic behaviour of the species. Ophiophagus hannah was standardised in 1945.
In the new study, this is the first of the four species of king cobra, bearing the common name of ‘Northern king cobra’. “Since it is evident that the type series of Cantor’s Hamadryas hannah is currently not extant (Article 75.3.4), we invoke Article 75 of the Code (ICZN 1999) to designate ZSI 8292, an adult collected by John Anderson, Superintendent of the Indian Museum from the Indian Botanical Gardens, Howrah, Kolkata, India, as the neotype of Ophiophagus hannah, in the context of the revision of the genus, in order to clarify the taxonomic status of the species (Article 75.3.1) and describe the characters of the specimen (Article 75.3.2), the data and description of the same unequivocally diagnosing the taxon from its congeners (Article 75.3.3),”they wrote.
The ‘type locality’ of this species is the north-western suburb of the township of Shibpur, 10 km from Kolkata.
This species’ range extends from “extreme eastern Pakistan, across the sub-Himalayan region of Kashmir, northern India, Nepal, Bhutan, Tibet, and south to the Godavari-Mahanadi-Ganges deltas of the Circar Coast in eastern India, east to the eastern coast of China, including Hong Kong, the range extending south to Indo-China, including Myanmar, Laos, Vietnam, Cambodia and parts of Thailand, presumably north of the Isthmus of Kra”.
The second species described is the ‘Sunda king cobra’. It inhabits areas south of the Kra isthmus or land bridge joining the Malay Peninsula with the rest of southeast Asia or Indochina.
The countries it is found in include extreme southern Thailand, West Malaysia, Singapore, and offshore islands), Sumatra, Borneo, Java, Bali, and some of the islands of the southern Philippines Archipelago.
The researchers gave it the scientific name of Ophiophagus bungarus. They note, “The specific epithet probably alludes to either morphological (partially undivided subcaudals) or behavioural (ophiophagous) characters of kraits (genus Bungarus).”
The third species is the Western Ghats king cobra (Ophiophagus kaalinga). Kaalinga comes from Kannada, alluding to the snake’s dark colouration.
“Ophiophagus kaalinga sp. nov. is endemic to the Western Ghats of south-western India, covering parts of Tamil Nadu, Kerala, Karnataka, Goa and the adjacent border of Maharashtra States. The species is known from the Ashambu hills near Kanyakumari (formerly, Cape Comorin), through the Agasthyamalai and Devarmalai ranges, the Cardamom hills, the Meghamalai mountains, the Anamalai-Palni ranges, across the Palghat Gap, through Nilgiri-Waynad, on to the Malnad regions (Coorg-Agumbe-Sharavathi-Anshi), until about the Goa Gap, abutting Maharashtra State,” the study notes.
It adds that the Western Ghats cobra is “essentially a hill-dwelling species, that is prevalent in mid-elevation (ca 500–900 m a.s.l.) rainforests, while extending lower to the very foothills (ca 100 m a.s.l.), in mesic windward western versant, or lower slopes (ca 300 m a.s.l.) in the drier leeward eastern versant, reaching up to the high elevation plateaus (ca 1800 m a.s.l.) covered with montane forests”.
The fourth species is the Luzon king cobra (Ophiophagus salvatana). “The specific epithet salvatana is the Tagalog (a vernacular language spoken in Luzon and adjacent regions of the Philippines, of Austronesian origin) name for the king cobra in the Luzon region (northern Philippines)…” the authors write.
This species is only found on Luzon in the northern Philippines. According to the researchers, “the affinities of king cobras from other islands of the Philippine Archipelago remain to be confirmed”.
The authors noted that their reclassification had implications for king cobra conservation as well as helping prevent deaths due to their bites.
“This, and future, taxonomic revisions of the king cobra are of particular importance for the conservation of these, the world’s largest venomous snakes. Recognising biological diversity is crucial to its assessment and conservation, and naming and listing species remains a typically essential precondition for conservation policy and action. In particular, failure to recognise units of biodiversity can potentially lead to their endangerment or extinction through neglect,” they wrote.
They laid special emphasis on the Western Ghats and Luzon king cobras. Both are restricted to relatively small regions that are biodiversity hotspots.
Their numbers are declining in the face of habitat destruction and degradation, capture for food, skin, medicine, killing out of ignorance and fear.
“Consequently, there is an urgent need to assess the conservation status of these two narrower endemics and formulate policies to ensure their survival,” the study read.
The reclassification could also help in toxicology and envenomation studies. “Although bites from O. hannah are rare, they are of medical significance, producing lethal neurotoxic effects and releasing large doses of venom, often leading to rapid death in human beings … Using the new taxonomy for these species may therefore be the first step to developing improved treatment of envenomation from Ophiophagus bites in the respective countries,” the authors wrote.