Naja kaouthia
Encyclopedia
The monocled cobra is a cobra
species, which is widespread across central
and southern Asia. It has been assessed as Least Concern
by IUCN owing to its large distribution, tolerance of a broad range of habitats, including anthropogenically altered environments, and its reported abundance. No major threats have been reported, and the species is not thought to be undergoing a significant population decline.
. Coloration in young is more constant. They are olivaceous or brownish to black above with or without a yellow or orange-coloured O-shaped mark upon the hood. They have a black spot on the lower surface of the hood on either side, and one or two black cross-bars on the belly behind it. The rest of the belly is usually of the same colour as the back, but paler. As age advances, they become paler, and when adult are brownish or olivaceous. Adult monocled cobras reach a length of 135 to 150 cm (53.1 to 59.1 in) with a tail length of 23 cm (9.1 in). Many larger specimens have been recorded, but they are rare. They have 25 to 31 scales
on the neck, 19 to 21, usually 21, on the body, and 17 or 15 on the front of the vent. They have 164 to 196 Ventral scales
and 43 to 58 subcaudal scales
.
The elongated nuchal ribs enable cobras to expand the anterior of the neck into a “hood”. When threatened, they will raise the anterior portions of their bodies, spread their hood, usually hiss loudly, and strike in an attempt to bite and defend themselves. A pair of fixed anterior fangs is present. Monocled cobras are non-spitting. Adults are a maximum of 2.3 metres (7.5 ft) in length. The dorsal surface may be yellow, brown, gray, or blackish and with or without ragged or clearly defined cross bands. The throat is usually immaculate and followed by a dark band. The ventral surface is the same color as the dorsal but the sub-caudals are light with dark edges.
Other sources mention 27-33 scale rows around the hood, 21 ahead of mid-body, and 170 to 197 ventral scales, 46 to 61 subcaudal scales.
body weight. The major toxic components in cobra venom
s are postsynaptic neurotoxin
s, which block the nerve transmission by binding specifically to the nicotinic acetylcholine receptor
, leading to flaccid paralysis
and even death by respiratory failure. The major α-neurotoxin in Naja kaouthia venom is a long neurotoxin, α-cobratoxin
; the minor α-neurotoxin is different from cobrotoxin in one residue
.
In case of intravenous injection the median lethal dose tested in mice is 0.373 mg / kg, and 0.225 mg per kg in case of intraperitoneal injection
.
Envenomation
usually presents predominately with extensive local necrosis
and systemic manifestations to a lesser degree. Drowsiness, neurological and neuromuscular symptoms will usually manifest earliest; hypotension
, flushing of the face, warm skin, and pain around bite site typically manifest within one to four hours following the bite; paralysis
, ventilatory failure or death could ensue rapidly, possibly as early as 60 minutes. The presence of fang marks does not always imply that envenomation actually occurred.
in the west through to China
, Vietnam
and Cambodia
, also occurs in the Malay Peninsula
and is native to Bangladesh
, Bhutan
, Myanmar
, Laos
, Nepal
, and Thailand
. They are found up to elevations of 1000 m (3,280.8 ft) above sea level, and prefer habitats associated with water, such as paddy field
s, swamp
s, and mangrove
s, but are also found in grasslands, shrublands, and forests, in agricultural land and human settlements, including cities.
They prey on a wide range of animals, such as rodents, toads, lizards, birds and their eggs, sometimes even their own species
.
Females lay between 16 and 33 egg
s per clutch. Incubation periods range from 55 to 73 days. Young are independent as soon as they hatch.
, however, collection from the wild is minimal and not likely to be causing significant population declines.
Since then, several monocled cobras were described under different scientific names:
Several varieties of monocled cobras were described under the binomial Naja tripudians between 1895 and 1913.
In 1940, Malcolm Arthur Smith
classified the monocled cobra as a subspecies of the spectacled cobra under the trinomial Naja naja kaouthia.
Naja
Naja is a genus of venomous elapid snakes. Although there are several other genera that share the common name, Naja are the most recognized and most widespread group of snakes commonly known as cobras. The genus Naja consists of 20 to 22 species, but has undergone several taxonomic revisions in...
species, which is widespread across central
Central Asia
Central Asia is a core region of the Asian continent from the Caspian Sea in the west, China in the east, Afghanistan in the south, and Russia in the north...
and southern Asia. It has been assessed as Least Concern
Least Concern
Least Concern is an IUCN category assigned to extant taxon or lower taxa which have been evaluated but do not qualify for any other category. As such they do not qualify as threatened, Near Threatened, or Conservation Dependent...
by IUCN owing to its large distribution, tolerance of a broad range of habitats, including anthropogenically altered environments, and its reported abundance. No major threats have been reported, and the species is not thought to be undergoing a significant population decline.
Characteristics
The monocled cobra has an O-shaped, or monocellate hood pattern, unlike that of the Indian cobraIndian Cobra
Indian Cobra or Spectacled Cobra is a species of the genus Naja found in the Indian subcontinent and a member of the "big four", the four species which inflict the most snakebites in India. This snake is revered in Indian mythology and culture, and is often seen with snake charmers...
. Coloration in young is more constant. They are olivaceous or brownish to black above with or without a yellow or orange-coloured O-shaped mark upon the hood. They have a black spot on the lower surface of the hood on either side, and one or two black cross-bars on the belly behind it. The rest of the belly is usually of the same colour as the back, but paler. As age advances, they become paler, and when adult are brownish or olivaceous. Adult monocled cobras reach a length of 135 to 150 cm (53.1 to 59.1 in) with a tail length of 23 cm (9.1 in). Many larger specimens have been recorded, but they are rare. They have 25 to 31 scales
Snake scales
Snakes, like other reptiles, have a skin covered in scales. Snakes are entirely covered with scales or scutes of various shapes and sizes. Scales protect the body of the snake, aid it in locomotion, allow moisture to be retained within, alter the surface characteristics such as roughness to aid in...
on the neck, 19 to 21, usually 21, on the body, and 17 or 15 on the front of the vent. They have 164 to 196 Ventral scales
Ventral scales
In snakes, the ventral scales are the enlarged and transversely elongated scales that extend down the underside of the body from the neck to the anal scale. When counting them, the first is the anteriormost ventral scale that contacts the paraventral row of dorsal scales on either side...
and 43 to 58 subcaudal scales
Subcaudal scales
In snakes, the subcaudal scales are the enlarged plates on the underside of the tail. These scales may be either single or divided and are preceded by the anal scale....
.
The elongated nuchal ribs enable cobras to expand the anterior of the neck into a “hood”. When threatened, they will raise the anterior portions of their bodies, spread their hood, usually hiss loudly, and strike in an attempt to bite and defend themselves. A pair of fixed anterior fangs is present. Monocled cobras are non-spitting. Adults are a maximum of 2.3 metres (7.5 ft) in length. The dorsal surface may be yellow, brown, gray, or blackish and with or without ragged or clearly defined cross bands. The throat is usually immaculate and followed by a dark band. The ventral surface is the same color as the dorsal but the sub-caudals are light with dark edges.
Other sources mention 27-33 scale rows around the hood, 21 ahead of mid-body, and 170 to 197 ventral scales, 46 to 61 subcaudal scales.
Venom
The median lethal dose is 0.28-0.33 mg per gram of mouseMouse
A mouse is a small mammal belonging to the order of rodents. The best known mouse species is the common house mouse . It is also a popular pet. In some places, certain kinds of field mice are also common. This rodent is eaten by large birds such as hawks and eagles...
body weight. The major toxic components in cobra venom
Venom
Venom is the general term referring to any variety of toxins used by certain types of animals that inject it into their victims by the means of a bite or a sting...
s are postsynaptic neurotoxin
Neurotoxin
A neurotoxin is a toxin that acts specifically on nerve cells , usually by interacting with membrane proteins such as ion channels. Some sources are more general, and define the effect of neurotoxins as occurring at nerve tissue...
s, which block the nerve transmission by binding specifically to the nicotinic acetylcholine receptor
Acetylcholine receptor
An acetylcholine receptor is an integral membrane protein that responds to the binding of acetylcholine, a neurotransmitter.-Classification:...
, leading to flaccid paralysis
Paralysis
Paralysis is loss of muscle function for one or more muscles. Paralysis can be accompanied by a loss of feeling in the affected area if there is sensory damage as well as motor. A study conducted by the Christopher & Dana Reeve Foundation, suggests that about 1 in 50 people have been diagnosed...
and even death by respiratory failure. The major α-neurotoxin in Naja kaouthia venom is a long neurotoxin, α-cobratoxin
Cobratoxin
α-Cobratoxin is a substance of the venom of certain Naja cobras. It is a muscle-type nicotinic acetylcholine receptor antagonist, which causes paralysis by preventing the binding of acetylcholine to the nAChR.-Source:...
; the minor α-neurotoxin is different from cobrotoxin in one residue
Residue (chemistry)
In chemistry, residue is the material remaining after a distillation or an evaporation, or to a portion of a larger molecule, such as a methyl group. It may also refer to the undesired byproducts of a reaction....
.
In case of intravenous injection the median lethal dose tested in mice is 0.373 mg / kg, and 0.225 mg per kg in case of intraperitoneal injection
Intraperitoneal injection
Intraperitoneal injection or IP injection is the injection of a substance into the peritoneum . IP injection is more often applied to animals than humans...
.
Envenomation
Envenomation
Envenomation is the process by which venom is injected into some animal by the bite of a venomous animal. Many kinds of animals, including mammals , reptiles , spiders , insects , employ venom for hunting and for self defense...
usually presents predominately with extensive local necrosis
Necrosis
Necrosis is the premature death of cells in living tissue. Necrosis is caused by factors external to the cell or tissue, such as infection, toxins, or trauma. This is in contrast to apoptosis, which is a naturally occurring cause of cellular death...
and systemic manifestations to a lesser degree. Drowsiness, neurological and neuromuscular symptoms will usually manifest earliest; hypotension
Hypotension
In physiology and medicine, hypotension is abnormally low blood pressure, especially in the arteries of the systemic circulation. It is best understood as a physiologic state, rather than a disease. It is often associated with shock, though not necessarily indicative of it. Hypotension is the...
, flushing of the face, warm skin, and pain around bite site typically manifest within one to four hours following the bite; paralysis
Paralysis
Paralysis is loss of muscle function for one or more muscles. Paralysis can be accompanied by a loss of feeling in the affected area if there is sensory damage as well as motor. A study conducted by the Christopher & Dana Reeve Foundation, suggests that about 1 in 50 people have been diagnosed...
, ventilatory failure or death could ensue rapidly, possibly as early as 60 minutes. The presence of fang marks does not always imply that envenomation actually occurred.
Distribution and habitat
Monocled cobras are distributed from IndiaIndia
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
in the west through to China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
, Vietnam
Vietnam
Vietnam – sometimes spelled Viet Nam , officially the Socialist Republic of Vietnam – is the easternmost country on the Indochina Peninsula in Southeast Asia. It is bordered by China to the north, Laos to the northwest, Cambodia to the southwest, and the South China Sea –...
and Cambodia
Cambodia
Cambodia , officially known as the Kingdom of Cambodia, is a country located in the southern portion of the Indochina Peninsula in Southeast Asia...
, also occurs in the Malay Peninsula
Malay Peninsula
The Malay Peninsula or Thai-Malay Peninsula is a peninsula in Southeast Asia. The land mass runs approximately north-south and, at its terminus, is the southern-most point of the Asian mainland...
and is native to Bangladesh
Bangladesh
Bangladesh , officially the People's Republic of Bangladesh is a sovereign state located in South Asia. It is bordered by India on all sides except for a small border with Burma to the far southeast and by the Bay of Bengal to the south...
, Bhutan
Bhutan
Bhutan , officially the Kingdom of Bhutan, is a landlocked state in South Asia, located at the eastern end of the Himalayas and bordered to the south, east and west by the Republic of India and to the north by the People's Republic of China...
, Myanmar
Myanmar
Burma , officially the Republic of the Union of Myanmar , is a country in Southeast Asia. Burma is bordered by China on the northeast, Laos on the east, Thailand on the southeast, Bangladesh on the west, India on the northwest, the Bay of Bengal to the southwest, and the Andaman Sea on the south....
, Laos
Laos
Laos Lao: ສາທາລະນະລັດ ປະຊາທິປະໄຕ ປະຊາຊົນລາວ Sathalanalat Paxathipatai Paxaxon Lao, officially the Lao People's Democratic Republic, is a landlocked country in Southeast Asia, bordered by Burma and China to the northwest, Vietnam to the east, Cambodia to the south and Thailand to the west...
, Nepal
Nepal
Nepal , officially the Federal Democratic Republic of Nepal, is a landlocked sovereign state located in South Asia. It is located in the Himalayas and bordered to the north by the People's Republic of China, and to the south, east, and west by the Republic of India...
, and Thailand
Thailand
Thailand , officially the Kingdom of Thailand , formerly known as Siam , is a country located at the centre of the Indochina peninsula and Southeast Asia. It is bordered to the north by Burma and Laos, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the...
. They are found up to elevations of 1000 m (3,280.8 ft) above sea level, and prefer habitats associated with water, such as paddy field
Paddy field
A paddy field is a flooded parcel of arable land used for growing rice and other semiaquatic crops. Paddy fields are a typical feature of rice farming in east, south and southeast Asia. Paddies can be built into steep hillsides as terraces and adjacent to depressed or steeply sloped features such...
s, swamp
Swamp
A swamp is a wetland with some flooding of large areas of land by shallow bodies of water. A swamp generally has a large number of hammocks, or dry-land protrusions, covered by aquatic vegetation, or vegetation that tolerates periodical inundation. The two main types of swamp are "true" or swamp...
s, and mangrove
Mangrove
Mangroves are various kinds of trees up to medium height and shrubs that grow in saline coastal sediment habitats in the tropics and subtropics – mainly between latitudes N and S...
s, but are also found in grasslands, shrublands, and forests, in agricultural land and human settlements, including cities.
Ecology and behaviour
Monocled cobras are most active at dusk and night, but are also found basking during daytime. If disturbed, they tend to head for cover. When provoked, they raise their forebody, extending the hood and hiss. They strikes only when threatened.They prey on a wide range of animals, such as rodents, toads, lizards, birds and their eggs, sometimes even their own species
Cannibalism
Cannibalism is the act or practice of humans eating the flesh of other human beings. It is also called anthropophagy...
.
Females lay between 16 and 33 egg
Egg (biology)
An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...
s per clutch. Incubation periods range from 55 to 73 days. Young are independent as soon as they hatch.
Threats
Monocled cobras are harvested for the skin tradeWildlife trade
The international wildlife trade is a serious conservation problem, addressed by the United Nations' Convention of International Trade in Endangered Species of Wild Fauna and Flora CITES, which currently has 175 member countries called Parties. The 15th meeting of the Parties took place in Doha,...
, however, collection from the wild is minimal and not likely to be causing significant population declines.
Conservation
Naja kaouthia is listed on CITES Appendix II. In places the distribution of this species coincides with protected areas, probably providing small safeguards.Taxonomic history
In 1831, Lesson first described the monocled cobra as a beautiful snake that is well distinct from the spectacled cobra, with 188 ventral scales and 53 pairs of caudal scales.Since then, several monocled cobras were described under different scientific names:
- In 1834, John Edward GrayJohn Edward GrayJohn Edward Gray, FRS was a British zoologist. He was the elder brother of George Robert Gray and son of the pharmacologist and botanist Samuel Frederick Gray ....
published Thomas HardwickeThomas HardwickeMajor-General Thomas Hardwicke was an English soldier and naturalist who was resident in India from 1777 to 1823. After returning to England he collaborated with John Edward Gray in the publication of Illustrations of Indian Zoology .At the age of 22, he joined the East India Company...
’s first illustration of a monocled cobra under the trinomialTrinomial nomenclatureIn biology, trinomial nomenclature refers to names for taxa below the rank of species. This is different for animals and plants:* for animals see trinomen. There is only one rank allowed below the rank of species: subspecies....
Naja tripudians var. fasciata. - In 1839, Thomas Cantor described a brownish monocled cobra with numerous faint yellow transverse stripes and a hood marked with a white ring under the binomialBinomial nomenclatureBinomial nomenclature is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin grammatical forms, although they can be based on words from other languages...
Naja larvata, found in Bombay, Calcutta and AssamAssamAssam , also, rarely, Assam Valley and formerly the Assam Province , is a northeastern state of India and is one of the most culturally and geographically distinct regions of the country...
.
Several varieties of monocled cobras were described under the binomial Naja tripudians between 1895 and 1913.
- Naja tripudians var. scopinucha 1895
- Naja tripudians var. unicolor 1876
- Naja tripudians var. viridis 1913
- Naja tripudians var. sagittifera 1913
In 1940, Malcolm Arthur Smith
Malcolm Arthur Smith
Malcolm Arthur Smith was a herpetologist and physician working in the Malay Peninsula.-Early life:He was interested in reptiles and amphibians from an early age...
classified the monocled cobra as a subspecies of the spectacled cobra under the trinomial Naja naja kaouthia.
- Naja kaouthia kaouthia – Deraniyagala, 1960
Further reading
- Wüster, Wolfgang (1993) A century of confusion: Asiatic cobras revisited. Vivarium 4 (4): 14–18
- Cox, Merel J. (1995) Naja kaouthia Herpetological Review 26 (3): 156–157
- Kyi, S. W., Zug, G. R. (2003) Unusual foraging behaviour of Naja kaouthia at the Moyingye Wetlands Bird Sanctuary, Myanmar. Hamadryad 27 (2): 265–266
- Wüster, W. Thorpe, R.S. (1991) Asiatic cobras: Systematics and snakebite. Experientia 47: 205–209
- Wüster, W., Thorpe, R.S., Cox, M.J., Jintakune, P., Nabhitabhata, J. (1995) "Population systematics of the snake genus Naja (Reptilia: Serpentes: Elapidae) in Indochina: Multivariate morphometrics and comparative mitochondrial DNA sequencing (cytochrome oxidase I)". Journal of Evolutionary Biolology 8: 493–510
- Wüster, W. (1996) Taxonomic changes and toxinology: Systematic revisions of the Asiatic cobras (Naja naja complex). Toxicon 34 (4): 399–406
- Wüster, W. (1998) The cobras of the genus Naja in India Hamadryad 23 (1): 15–32
