Naja | ||||||||||||||||||
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A cobra
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Scientific classification | ||||||||||||||||||
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Naja is a genus of venomous snakes belonging to the Elapidae family and ranging from Africa to the Middle East, Central Asia, South Asia (Indian subcontinent), Southeast Asia, and far East Asia. 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 23 species, but has undergone several taxonomic revisions in recent years, so sources vary greatly.[1]
The generic name naja is a Latinisation of the Sanskrit word nāgá (नाग) meaning "cobra" or snake.
Different Naja species range in length and most are relatively slender-bodied snakes. Most species are capable of attaining lengths of 1.84 m (6.04 ft). Maximum lengths for some of the larger species of cobra is around 3.1 m (10.17 ft), with the Forest cobra being the longest species.[2][3] All have a characteristic ability to raise the front quarters of their bodies off the ground and flatten their necks to form a hood to appear larger to a potential predator.
All species in the genus Naja are capable of delivering a fatal bite in a human. Most species have strongly neurotoxic venom, which attacks the nervous system, causing paralysis, but many also have cytotoxic features which causes swelling and necrosis and has a significant anticoagulant effect. Some also have cardiotoxic components to their venom.
Several Naja species, referred to as spitting cobras, have developed a specialized venom delivery mechanism, in which their front fangs, instead of releasing venom through the tips (similar to a hypodermic needle), have a rifled opening in the front surface which allows the snake to propel the venom out of the mouth. While typically referred to as spitting, the action is more like squirting. The range and accuracy with which they can shoot their venom varies from species to species, but it is used primarily as a defense mechanism. Once sprayed onto a victim's skin, the venom acts as a severe irritant. If it is introduced to the eye, it can cause a severe burning sensation and temporary or even permanent blindness if not cleaned out immediately and thoroughly.
Murine (mice) subcutaneous (SC) LD50 values for some cobra species include 0.20 mg/kg for Naja philippinensis (Philippine cobra) which is considered to be the most venomous species, 0.40 mg/kg for Naja oxiana (Central Asian cobra), 0.80 mg/kg for Naja naja (Indian cobra),[4] 1.15 mg/kg for Naja haje (Egyptian cobra), 2.0 mg/kg for Naja nigricollis (Black-necked spitting cobra), 0.72 mg/kg for Naja nivea (Cape cobra),[5] and 0.53 mg/kg for Naja atra (Chinese cobra).[6]
Some murine intravenous (IV) LD50 values include 0.29 mg/kg for Naja melanoleuca (Forest cobra), 0.345 mg/kg for Naja atra (Chinese cobra), 0.373 mg/kg for Naja kaouthia (Monocled cobra), and 0.96 mg/kg for Naja oxiana (Central Asian cobra).[5]
The murine intraperitoneal (IP) LD50 of Naja annulata (Banded water cobra) and Naja christyi (Congo water cobra) venoms were 0.143 and 0.120 mg/kg, respectively.[7] Other IP LD50 values include Naja haje (Egyptian cobra) at 0.185 mg/kg, for Naja kaouthia (Monocled cobra) it's 0.225 mg/kg, for Naja naja (Indian cobra) it's 0.315 mg/kg, for Naja melanoleuca (Forest cobra) it's 0.324 mg/kg, for Naja nivea (Cape cobra) it's 0.4 mg/kg, for Naja nigricollis (Black-necked spitting cobra) it's 0.4 mg/kg, and for Naja pallida (Red spitting cobra) it's 2.0 mg/kg.[5]
The genus contains several species complexes of closely related and often similar species, some of them only recently described or defined. Several recent taxonomic studies have revealed species not included in the current listing in ITIS:[1]
Two recent molecular phylogenetic studies have also supported the incorporation of the species normally assigned to the genera Boulengerina and Paranaja into Naja, as both are closely related to the forest cobra (Naja melanoleuca) [11][12]
Species[1] | Authority[1] | Subsp.*[1] | Common name | Geographic range |
---|---|---|---|---|
N. anchietae | Bocage, 1879 | 0 | Anchieta's cobra | Angola, Botswana, Namibia, Zambia, eastern Zimbabwe |
N. annulata | (Buchholz and Peters, 1876) | 1 | Banded water cobra, Ringed water cobra | Cameroon, Central African Republic, Democratic Republic of Congo, Republic of Congo, Equatorial Guinea, Gabon, Rwanda, and the province of Cabinda in Angola |
N. annulifera | Peters, 1854 | 0 | Snouted cobra | Botswana, Malawi, Mozambique, South Africa, Swaziland, Zambia, Zimbabwe |
N. arabica | Scortecci, 1932 | 0 | Arabian cobra | Oman, Saudi Arabia, Yemen |
N. ashei | Wüster & Broadley, 2007 | 0 | Ashe's spitting cobra, Giant spitting cobra | Southern Ethiopia, Kenya, Somalia, eastern Uganda |
N. atra | Cantor, 1842 | 0 | Chinese cobra | Southern China, Northern Laos, Taiwan, northern Vietnam |
N. christyi | (Boulenger, 1904) | 0 | Congo water cobra | Democratic Republic of Congo, Republic of Congo, and in the province of Cabinda in Angola |
N. haje | (Linnaeus, 1758) | Egyptian cobra | Algeria, Burkina Faso, Cameroon, Central African Republic, northern Democratic Republic of the Congo, Chad, Egypt, Eritrea, Ethiopia, Kenya, Libya, Mali, Mauritania, Morocco, Niger, Nigeria, Somalia, Sudan, Tanzania, Togo, Tunisia, Uganda, Western Sahara | |
N. kaouthia | Lesson, 1831 | 0 | Monocled cobra | Bangladesh, Bhutan, Burma, Cambodia, southern China, eastern India, Laos, northwestern Malaysia, Nepal, Thailand, southeastern Tibet, Vietnam |
N. katiensis | Angel, 1922 | 0 | West African spitting cobra, Katien spitting cobra, Mali cobra | Benin, Burkina Faso, Cameroon, Ghana, Guinea, Ivory Coast, Mali, Gambia, Mauritania, Niger, Nigeria, Senegal, Togo |
N. mandalayensis | Slowinski & Wüster, 2000 | 0 | Mandalay spitting cobra, Burmese spitting cobra | Burma |
N. melanoleuca | Hallowell, 1857 | 0 | Forest cobra | Angola, Benin, Burkina Faso, Burundi, Cameroon, Central African Republic, Chad, Democratic Republic of the Congo (Zaire), Congo, Ethiopia, Gabon, Ghana, Gambia, Guinea, Guinea Bissau, Ivory Coast, Kenya, Liberia, Malawi, Mali, Mozambique, Niger, Nigeria, Rwanda, Sao Tom`e, Senegal, Sierra Leone, Somalia, South Africa, Sudan, Tanzania, Togo, Uganda, Zambia, Zimbabwe |
N. mossambica | Peters, 1854 | 0 | Mozambique spitting cobra | Extreme SE Angola, Botswana, Malawi, Mozambique, Somalia, NE Namibia, South Africa, Swaziland, Tanzania (including Pemba Island), Zambia, Zimbabwe |
N. multifasciata | Werner, 1902 | 2 | Many-banded cobra, Burrowing cobra | Cameroon, Central African Republic, Democratic Republic of the Congo (Zaire), Equatorial Guinea, Gabon, Republic of Congo (Congo) |
N. najaT | (Linnaeus, 1758) | 0 | Indian cobra, Spectacled cobra | Bangladesh, Bhutan, India, Nepal, Pakistan, Sri Lanka |
N. nigricincta | Bogert, 1940 | 1 | Zebra spitting cobra | Angola, Namibia, South Africa |
N. nigricollis | Reinhardt, 1843 | 0 | Black-necked spitting cobra | Angola, Benin, Burkina Faso, Burundi, Cameroon, Central African Republic, Chad, Democratic Republic of the Congo (except in the center), Congo, Ethiopia, Gabon, Gambia, Ghana, Guinea Bissau, Guinea, Ivory Coast, Kenya, Liberia, Mali, Mauritania, Namibia, Niger, Nigeria, Rwanda, Senegal, Sierra Leone, Sudan, Tanzania, Somalia, Togo, Uganda, Zambia |
N. nivea | (Linnaeus, 1758) | 0 | Cape cobra, Yellow Cobra | Botswana, Lesotho, Namibia, South Africa |
N. nubiae | Wüster & Broadly, 2003 | 0 | Nubian spitting cobra | Chad, Egypt, Eritrea, Niger, Sudan |
N. oxiana | (Eichwald, 1831) | 0 | Central Asian cobra, Caspian cobra, Oxus cobra, Russian cobra | Afghanistan, North-west India, Iran, Kyrgyzstan, Pakistan, Tajikistan, Turkmenistan, Uzbekistan |
N. pallida | Boulenger, 1896 | 0 | Red spitting cobra | Djibouti, Ethiopia, Kenya, Somalia, Tanzania |
N. philippinensis | Taylor, 1922 | 0 | Philippine cobra | Northern Philippines (Luzon, Mindoro) |
N. sagittifera | Wall, 1913 | 0 | Andaman cobra | India (Andaman Islands) |
N. samarensis | Peters, 1861 | 0 | Samar cobra, Peters' cobra, Visayan cobra, Southeastern Philippine cobra | Southern Philippines (Mindanao, Bohol, Leyte, Samar, Camiguin) |
N. senegalensis | Trape, Chirio & Wüster, 2009 | 0 | Senegalese Cobra | Benin, Burkina Faso, Ghana, Guinea, ?Guinea-Bissau, ?Ivory Coast, Mali, Niger, Nigeria, Senegal |
N. siamensis | Laurenti, 1768 | 0 | Indochinese spitting cobra, Isan spitting cobra, Black and white spitting cobra | Cambodia, Laos, Thailand, Vietnam |
N. sputatrix | F. Boie, 1827 | 0 | Javan spitting cobra, Indonesian cobra | Indonesia (Java, Lesser Sunda Islands, East Timor) |
N. sumatrana | Müller, 1887 | 0 | Equatorial spitting cobra, Golden spitting cobra, Sumatran spitting cobra | Brunei, Indonesia (Sumatra, Borneo, Bangka, Belitung), Malaysia, Philippines (Palawan), southern Thailand, Singapore |
*) Not including the nominate subspecies.
T) Type species.[13]