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Naja is a genus of venomous elapid commonly known as (or " true cobras"). Various species occur throughout Africa, Southwest Asia, South Asia, and Southeast Asia. Several other elapid species are often called "cobras", such as the king cobra and the rinkhals, but they are not "true cobras", in that they do not belong to the genus Naja. (1993). 9780916984281, Society for the Study of Amphibians & Reptiles. 522 pp.. . ISBN 9780916984281
Until recently, the genus Naja had 20 to 22 species, but it has undergone several taxonomic revisions in recent years, so sources vary greatly. Wide support exists, though, for a 2009 revision that synonymised the genera Boulengerina and Paranaja with Naja. According to that revision, the genus Naja now includes 38 species.
Several Naja species, referred to as , have a specialized venom delivery mechanism, in which their Proteroglypha, instead of ejecting venom downward through an elongated discharge orifice (similar to a hypodermic needle), have a shortened, rounded opening in the front surface, which ejects the venom forward, 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, and it is used primarily as a defense mechanism. The venom has little or no effect on unbroken skin, but if it enters the eyes, it can cause a severe burning sensation and temporary or even permanent blindness if not washed out immediately and thoroughly.
A recent study showed that all three spitting cobra lineages have evolved higher pain-inducing activity through increased phospholipase A2 levels, which potentiate the pain-inducing action of the cytotoxins present in most cobra venoms. The timing of the origin of spitting in African and Asian Naja species corresponds to the separation of the human and chimpanzee evolutionary lineages in Africa and the arrival of Homo erectus in Asia. The authors therefore hypothesize that the arrival of bipedal, tool-using primates may have triggered the evolution of spitting in cobras.
The Caspian cobra ( N. oxiana) of Central Asia is the most venomous Naja species. According to a 2019 study, the mouse via intravenous injection value for Naja oxiana (Iranian specimens) was estimated to be 0.14 mg/kg (0.067-0.21 mg/kg) more potent than the Sympatry Pakistani Naja naja karachiensis and Naja naja indusi found in far north and northwest India and adjacent Pakistani border areas (0.22 mg/kg), the Thailand Naja kaouthia (0.2 mg/kg), and Naja philippinensis at 0.18 mg/kg (0.11-0.3 mg/kg). (1984) listed a subcutaneous value of 0.2 mg/kg (0.16-0.47 mg/kg) for N. oxiana. The crude venom of N. oxiana produced the lowest known lethal dose (LCLo) of 0.005 mg/kg, the lowest among all cobra species ever recorded, derived from an individual case of envenomation by intracerebroventricular injection. The Naja annulata's was estimated to be 0.17 mg/kg via IV according to Christensen (1968). The Philippine cobra ( N. philippinensis) has an average murine of 0.18 mg/kg IV ( Tan et al, 2019). Minton (1974) reported 0.14 mg/kg IV for the Philippine cobra. (1974). 9780398030513, C.C. Thomas. ISBN 9780398030513 256 pp. The Samar cobra ( Naja samarensis), another cobra species endemic to the southern islands of the Philippines, is reported to have a of 0.2 mg/kg, similar in potency to the ( Naja kaouthia) which also have a of 0.2 mg/kg. The Indian cobra that are Sympatry with N. oxiana, in Pakistan and far northwest India, also have a high potency of 0.22 mg/kg.
Other highly venomous species are the forest cobras and/or water cobras ( Boulengerina subgenus). The murine intraperitoneal of Naja annulata and Naja christyi venoms were 0.143 mg/kg (range of 0.131 mg/kg to 0.156 mg/kg) and 0.120 mg/kg, respectively. Christensen (1968) also listed an IV of 0.17 mg/kg for N. annulata. The Chinese cobra ( N. atra) is also highly venomous. Minton (1974) listed a value of 0.3 mg/kg intravenous (IV), while Lee and Tseng list a value of 0.67 mg/kg Subcutis (SC). The of the Cape cobra ( N. nivea) according to Minton, 1974 was 0.35 mg/kg (IV) and 0.4 mg/kg (SC). The Senegalese cobra ( N. senegalensis) has a murine of 0.39 mg/kg (Tan et al, 2021) via IV. The Egyptian cobra ( N. haje) of locality had an IV of 0.43 mg/kg (0.35–0.52 mg/kg).
Many factors influence the differences in cases of fatality among different species within the same genus. Among cobras, the cases of fatal outcome of bites in both treated and untreated victims can be quite large. For example, mortality rates among untreated cases of envenomation by the cobras as a whole group ranges from 6.5–10% for N kaouthia. to about 80% for N. oxiana. Mortality rate for Naja atra is between 15 and 20%, 5–10% for N. nigricollis, 50% for N. nivea, 20–25% for N. naja, In cases where victims of cobra bites are medically treated using normal treatment protocol for elapid type envenomation, differences in prognosis depend on the cobra species involved. The vast majority of envenomated patients treated make quick and complete recoveries, while other envenomated patients who receive similar treatment result in fatalities. The most important factors in the difference of mortality rates among victims envenomated by cobras is the severity of the bite and which cobra species caused the envenomation. The Caspian cobra ( N. oxiana) and the Philippine cobra ( N. philippinensis) are the two cobra species with the most toxic venom based on studies on mice. Both species cause prominent neurotoxicity and progression of life-threatening symptoms following envenomation. Death has been reported in as little as 30 minutes in cases of envenomation by both species. N. philippinensis purely neurotoxic venom causes prominent neurotoxicity with minimal local tissue damage and pain and patients respond very well to antivenom therapy if treatment is administered rapidly after envenomation. Envenomation caused by N. oxiana is much more complicated. In addition to prominent neurotoxicity, very potent cytotoxic and Cardiotoxicity components are in this species' venom. Local effects are marked and manifest in all cases of envenomation: severe pain, severe swelling, bruising, blistering, and tissue necrosis. Renal damage and cardiotoxicity are also clinical manifestations of envenomation caused by N. oxiana, though they are rare and secondary. The untreated mortality rate among those envenomed by N. oxiana approaches 80%, the highest among all species within the genus Naja. Antivenom is not as effective for envenomation by this species as it is for other Asian cobras within the same region, like the Indian cobra ( N. naja) and due to the dangerous toxicity of this species' venom, massive amounts of antivenom are often required for patients. As a result, a monovalent antivenom serum is being developed by the Razi Vaccine and Serum Research Institute in Iran. Response to treatment with antivenom is generally poor among patients, so mechanical ventilation and endotracheal intubation is required. As a result, mortality among those treated for N. oxiana envenomation is still relatively high (up to 30%) compared to all other species of cobra (<1%).
Two recent molecular phylogenetic studies have also supported the incorporation of the species previously assigned to the genera Boulengerina and Paranaja into Naja, as both are closely related to the forest cobra ( Naja melanoleuca).; ; Miguel Vences; Branch, W.R.; ; ; (2005). "Molecular systematics of African Colubroidea (Squamata: Serpentes)". pp. 221–228. In: ; ; (editors) (2005). African Biodiversity: Molecules, Organisms, Ecosystems. Proceedings of the 5th International Symposium on Tropical Biology. Bonn: Museum Koenig. In the most comprehensive phylogenetic study to date, 5 putative new species were initially identified, of which 3 have since been named.
The controversial amateur herpetologist Raymond Hoser proposed the genus Spracklandus for the African spitting cobras.Raymond Hoser (2009). " Naja, Boulengerina and Paranaja". Australasian Journal of Herpetology 7: 1–15. Wallach et al. suggested that this name was not published according to the Code and suggested instead the recognition of four subgenera within Naja: Naja for the Asiatic cobras, Boulengerina for the African forest, water and burrowing cobras, Uraeus for the Egyptian and Cape cobra group and Afronaja for the African spitting cobras. International Commission on Zoological Nomenclature issued an opinion that it "finds no basis under the provisions of the Code for regarding the name Spracklandus as unavailable".
Asiatic cobras are believed to further be split into two groups of southeastern Asian cobras ( N. siamensis, N. sumatrana, N. philippinensis, N. samarensis, N. sputatrix, and N. mandalayensis) and western and northern Asian cobras ( N. oxiana, N. kaouthia, N. sagittifera, and N. atra) with Naja naja serving as a basal lineage to all species. (preprint).
Medical importance
The Naja species are a medically important group of snakes due to the number of bites and fatalities they cause across their geographical range. They range throughout Africa (including some parts of the Sahara where Naja haje can be found), Southwest Asia, Central Asia, South Asia, East Asia, and Southeast Asia. Roughly 30% of bites by some cobra species are dry bites, thus do not cause envenomation (a dry bite is a bite by a venomous snake that does not inject venom). Brown (1973) noted that cobras with a higher rates of 'sham strikes' tend to be more venomous, while those with a less toxic venom tend to envenomate more frequently when attempting to bite. This can vary even between specimens of the same species. This is unlike related elapids, such as those species belonging to Dendroaspis (mambas) and Bungarus (kraits), with mambas tending to almost always envenomate and kraits tending to envenomate more often than they attempt 'sham strikes'.
Mahmoud Latifi (1984). 9780916984229, Society for the Study of Amphibians & Reptiles. ISBN 9780916984229 156 pp.
Taxonomy
The genus contains several of closely related and often similar-looking species, some of them only recently described or defined. Several recent taxonomic studies have revealed species not included in the current listing in ITIS:
Species
N. anchietae Bocage, 1879 0 Anchieta's cobra (Angolan Cobra) Angola, Botswana, Namibia, Zambia, eastern Zimbabwe N. annulata Buchholz & Wilhelm Peters, 1876 1 Banded water cobra Cameroon, the Central African Republic, the Democratic Republic of the Congo (Zaire), the Republic of Congo, Equatorial Guinea, Gabon, Rwanda, and the province of Cabinda in Angola N. annulifera W. Peters, 1854 0 Snouted cobra Botswana, Malawi, Mozambique, South Africa, Swaziland, Zambia, Zimbabwe † Naja antiqua , 1976 0 Miocene-aged strata of Morocco N. arabica , 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 the Democratic Republic of the Congo (Zaire), the Republic of Congo, and the province of Cabinda in Angola N. fuxi , Gernot Vogel, & , 2022 0 Brown banded cobra China, Myanmar, Laos, Thailand, Vietnam N. guineensis Broadley, Trape, Laurent Chirio, & Wüster, 2018 0 Black forest cobra Ghana, Guinea, Guinea-Bissau, the Ivory Coast, Liberia, Sierra Leone, Togo N. haje Carl Linnaeus, 1758 0 Egyptian cobra Tanzania, Kenya, Somalia, Ethiopia, Uganda, South Sudan, Sudan, Cameroon, Nigeria, Niger, Burkina Faso, Mali, Senegal, Mauritania, Morocco, Algeria, Tunisia, Libya, and Egypt † Naja iberica , 1985 Miocene-aged strata of Spain 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 Fernand Angel, 1922 0 Mali cobra (Katian spitting cobra) Benin, Burkina Faso, Cameroon, Ghana, Guinea, the Ivory Coast, Mali, Gambia, Mauritania, Niger, Nigeria, Senegal, Togo N. mandalayensis Slowinski & Wüster, 2000 0 Mandalay spitting cobra (Burmese spitting cobra) Myanmar (Burma) N. melanoleuca Hallowell, 1857 0 Forest cobra Angola, Benin, Cameroon, the Central African Republic, the Republic of Congo, the Democratic Republic of the Congo (Zaire), Equatorial Guinea, Gabon, Nigeria N. mossambica W. Peters, 1854 0 Mozambique spitting cobra extreme southeastern Angola, Botswana, Malawi, Mozambique, Somalia, northeastern Namibia, South Africa, Swaziland, Tanzania (including Pemba Island), Zambia, Zimbabwe N. multifasciata (Franz Werner, 1902) 0 Many-banded cobra Cameroon, Congo, the Democratic Republic of the Congo (Zaire), Gabon N. naja (Linnaeus, 1758) 0 Indian cobra (spectacled cobra) Bangladesh, Bhutan, India, Nepal, Pakistan, Sri Lanka N. nana & Trape, 2020 0 Dwarf water cobra Democratic Republic of Congo N. nigricincta Bogert, 1940 1 Zebra spitting cobra Angola, Namibia, South Africa N. nigricollis Johan Reinhardt, 1843 0 Black-necked spitting cobra Angola, Benin, Burkina Faso, Burundi, Cameroon, the Central African Republic, Chad, the Democratic Republic of the Congo (Zaire) (except in the central region), Congo, Ethiopia, Gabon, Gambia, Ghana, Guinea-Bissau, Guinea, the 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 & Broadley, 2003 0 Nubian spitting cobra Chad, Egypt, Eritrea, Niger, Sudan N. obscura & Trape, 2023 0 Obscure cobra Egypt N. oxiana (Karl Eichwald, 1831) 0 Caspian cobra Afghanistan, northwestern India, Iran, Kyrgyzstan, Pakistan, Tajikistan, Turkmenistan, Uzbekistan N. pallida Boulenger, 1896 0 Red spitting cobra Djibouti, Ethiopia, Kenya, Somalia, Tanzania N. peroescobari Ceríaco, Marques, Andreas Schmitz & Bauer, 2017 0 São Tomé forest cobra, cobra preta São Tomé and Príncipe (São Tomé) N. philippinensis Taylor, 1922 0 Philippine cobra the Philippines (Luzon, Mindoro) † Naja romani (Hofstetter, 1939) 0 † Miocene-aged strata of France, Germany, Austria, Russia, Hungary, Greece and Ukraine. N. sagittifera Wall, 1913 0 Andaman cobra India (the Andaman Islands) N. samarensis W. Peters, 1861 0 Samar cobra the Philippines (Mindanao, Bohol, Leyte, Samar, Camiguin) N. savannula Broadley, Trape, Chirio & Wüster, 2018 0 West African banded cobra Benin, Burkina Faso, Cameroon, Chad, Gambia, Ghana, Guinea, the Ivory Coast, Mali, Niger, Nigeria, Senegal, Togo N. senegalensis Trape, Chirio & Wüster, 2009 0 Senegalese cobra Benin, Burkina Faso, Ghana, Guinea, Guinea-Bissau, the Ivory Coast, Mali, Niger, Nigeria, Senegal N. siamensis Laurenti, 1768 0 Indochinese spitting cobra Cambodia, Laos, Thailand, Vietnam N. sputatrix Friedrich Boie, 1827 0 Javan spitting cobra Indonesia (Java, the Lesser Sunda Islands, East Timor) N. subfulva Laurent, 1955 0 Brown forest cobra Angola, Burundi, Cameroon, the Central African Republic, Chad, the Republic of Congo, the Democratic Republic of the Congo (Zaire), Ethiopia, Kenya, Malawi, Mozambique, Nigeria, Rwanda, Somalia, South Africa, South Sudan, Tanzania, Uganda, Zambia, Zimbabwe N. sumatrana J. Müller, 1887 0 Equatorial spitting cobra Brunei, Indonesia (Sumatra, Borneo, Bangka, Belitung), Malaysia, the Philippines (Palawan), southern Thailand, Singapore
† Extinct
T Type species
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