Indian Cobra

The Indian cobra, also known as the spectacled cobra, Asian cobra or binocellate cobra, is a venomous snake belonging to the family Elapidae. Native to the Indian subcontinent, it is one of the Big Four snake species responsible for the majority of medically significant snakebites in South Asia. Beyond its biological significance, the Indian cobra occupies an important place in Indian cultural and religious traditions and is legally protected under the Wildlife Protection Act of 1972.

Taxonomy

The genus name Naja and the species epithet naja derive from a Latinised form of the Sanskrit term for “cobra”. The species was formally described by Carl Linnaeus in 1758, while the genus Naja had earlier been established by Josephus Nicolaus Laurenti in 1768. Asian cobras were historically grouped as subspecies of Naja naja, but taxonomic revisions during the 1990s led to recognition of several distinct species within the subgenus Naja.
Naja naja is widely regarded as the prototypical Asian cobra and represents the standard morphological and behavioural model for the group.

Physical Description

The Indian cobra is a moderately sized, heavy-bodied snake that is instantly recognisable by the broad hood it expands when threatened. Many individuals display a distinctive hood marking resembling a pair of spectacles, formed by two circular spots connected by a curved line.
Key physical characteristics include:

• An elliptical, slightly depressed head only subtly distinct from the neck
• A short, rounded snout with large nostrils
• Medium-sized eyes with round pupils
• Adult lengths commonly within a moderate range, with larger specimens occasionally recorded from Sri Lanka

Colouration varies widely across its extensive range. Ventral surfaces may be grey, yellow, tan, brown, reddish or black. Dorsal surfaces may feature speckles, bands, or a hood mark. In parts of southern Pakistan juveniles can be grey and patterned, while adults are often uniformly black (melanistic).
Throat patterns differ between populations, with many individuals displaying a pale throat followed by dark banding, along with mottling along the underside.
Scalation includes 21–25 rows of strongly oblique dorsal scales at midbody, 171–197 ventral scales, 48–75 divided subcaudals and a single anal scale. The arrangement of upper and lower labials, preocular and postocular scales, and temporal scales aids in identification.

Similar Species

Several snake species resemble the Indian cobra and may be mistaken for it:

• Oriental rat snake (Ptyas mucosa), a much larger but non-venomous species
• Banded racer (Argyrogena fasciolata)
• Indian smooth snake (Wallophis brachyura)
• Monocled cobra (Naja kaouthia), distinguishable by its O-shaped hood marking
• Caspian cobra (Naja oxiana), which co-occurs in Pakistan and Afghanistan but lacks the deep black melanistic phase of Naja naja

Geographic Distribution

The Indian cobra is widespread throughout the Indian subcontinent, occurring in:

• India
• Pakistan
• Sri Lanka
• Bangladesh
• Southern Nepal

It is generally absent from the highest Himalayan elevations, extreme deserts and some regions of Kashmir and Assam. Occasional records from Bhutan and eastern Afghanistan have been noted.
The species occupies habitats ranging from forests and agricultural landscapes to wetlands, rocky terrain and urban peripheries. It is often found near water and seeks shelter in tree hollows, embankment burrows, termite mounds and small mammal dens.

Reproduction

The Indian cobra is oviparous, breeding from April to July. Females lay 10 to 30 eggs in protected sites such as rat holes or termite mounds. Incubation lasts 48–69 days, after which fully independent hatchlings emerge, each equipped with functional venom glands and measuring several inches in total length.

Venom

The venom of Naja naja is composed primarily of potent postsynaptic neurotoxins and cardiotoxins. These disrupt nerve signal transmission and cardiac function, leading to muscle paralysis and potentially fatal respiratory failure. Additional enzymes, including hyaluronidase, facilitate venom diffusion through tissues.
Potency data vary geographically, with reported mouse LD₅₀ values ranging from 0.22 mg/kg in Pakistani populations to approximately 0.84 mg/kg in Indian populations. Average venom yields generally fall between 170–250 mg dry weight, though exceptional yields exceeding 600 mg have been recorded.
Despite the high incidence of bites, fatalities can be substantially reduced through the administration of antivenom, which is widely available for the Big Four species. Untreated mortality rates may reach 20–30%, but fall significantly with prompt medical care.

Cultural Significance

The Indian cobra features prominently in Hindu mythology, often symbolising power, fertility and protection. Cobras are associated with deities such as Shiva and Vishnu and appear frequently in religious iconography. The species is also traditionally linked with snake charmers, though such practices have declined due to wildlife protection laws.