African spitting cobra
| African spitting cobra | ||||||||||||
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Black colored specimen of the African spitting cobra |
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| Well nigricollis | ||||||||||||
| Reinhardt , 1843 |
The African spitting cobra ( Naja nigricollis ), also known as the black-necked spitting cobra or black-necked cobra , is a species of the real cobras (genus Naja ) that is widespread on the African continent.
features
The African spitting cobra reaches an average body length of 1.5 to 2.0 meters, but can also be up to 2.7 meters long. This makes it the largest species of the African spitting cobra . The coloration of the snakes is highly variable and regionally different. The usual shape is a single color, dark olive-brown to gray-brown or black on the top and is so similar to the Mozambique spitting cobra ( Naja mossambica ). The belly side is colored yellow to reddish, on the throat the snake has a wide black band. The zebra spitting cobra ( Naja nigricolis nigricincta ), a subspecies, is conspicuously striped and has 50 to 85 black horizontal stripes on a light brown or pink body and 32 other horizontal stripes on the tail, all of which are present on both the back and the belly . The head of these animals is solid black. The third subspecies, Naja nigricollis woodi , has a solid black body.
The head of the snake has six, rarely seven, upper lip shields , of which the third, rarely the fourth, is connected to the eyes. In addition, the snakes have two fore-eye shields and three rear-eye shields as well as 2 + 4 or 2 + 5 temporal shields . The lower edge of the mouth gap is formed by nine, rarely eight or ten lower lip shields . The African spitting cobra has 17 to 23 rows of dorsal scales in the middle of the body. The ventral side is covered with 176 to 228 ventral shields , which are followed by an undivided anal shield and 54 to 74 paired under tail shields . In the meantime, the zebra spitting cobra has been separated from Naja nigricollis and listed as a separate species with the two subspecies Naja nigricincta nigricincta and Naja nigricincta woodi (WÜSTER et al., 2007).
distribution and habitat
The African spitting cobra is common in large parts of tropical Africa south of the Sahara, from Senegal to Somalia and to the southeast to Angola . The nominate form lives in the entire distribution area, including in East Africa in Tanzania , Kenya , Uganda , Burundi and Rwanda as well as in south-western Africa in Namibia , Angola and South Africa . The subspecies Naja nigricollis woodi occurs in central and western Namibia and in the Cape Province in South Africa while Naja nigricolis nigricincta can be found in central and northern Namibia and southern Angola.
The preferred habitat can be highly variable and includes dry and humid savannah areas , sandy desert areas, stony scree and dry watercourses as well as the Karoo area in South Africa .
Way of life
The African spitting cobra is mostly nocturnal and therefore only catches prey at night. During the day it hides in termite burrows , rodent burrows, hollow trees and tree stumps as well as in the root area of trees. The young, however, are diurnal. Like other cobras, the African spitting cobra is primarily ground-living, but it can also climb well. It can also be found regularly in human settlements and often hunts in the area of chicken yards . It feeds on small prey such as amphibians, lizards, smaller snakes, rodents, and birds.
As a spitting cobra , it is able to inject its venom against a potential enemy when threatened, whereby this species can spit over distances of up to three meters. She lifts her head off the ground and spreads her neck, which is narrower in her than in other cobras. The fangs have a venom canal that opens outwards at the tip of the tooth and thus enables the animals to “spit” their poison. The poison has no effect on the skin, but it stings the eyes and can cause permanent blindness .
The snake lay eggs ( oviparous ), the females lay 8 to 20 eggs.
Poisonous effect
The potentially deadly poison of the cobras and thus that of the African spitting cobra is primarily a postsynaptic nerve (neurotoxin) and cellular poison (cytotoxin). The poisons of the African spitting cobra and the Mozambique spitting cobra have a property that is atypical for elapids in that they cause severe local tissue damage. Bite survivors may therefore have severe wounds or even lose bitten extremities.
Systematics
The African spitting cobra is a species of the real cobras (genus Naja ), which are distributed in around 22 species in Asia and Africa.
In addition to the nominate form, there is also a subspecies with Naja nigricollis woodi . The Naja nigricolis nigricincta , which has long been listed as a subspecies, was assigned the status of its own species as a result of DNA sequence analyzes of the species group around Naja nigricollis : Naja nigricincta .
supporting documents
- ↑ a b c d e f g Johan Marais: Complete Guide To Snakes Of Southern Africa. Struik Publishers 2005; Pp. 110-113. ISBN 978-1-86872-932-6 ( scan from Google Books (incorrectly named) )
- ↑ a b c d e f Mark O'Shea: Venomous Snakes of the World. New Holland Publishers 2008; P. 73. ( Scan from Google Books )
- ^ Dietrich Mebs: Poison animals. A handbook for biologists, toxicologists, doctors and pharmacists . Wissenschaftliche Verlagsges. Stuttgart; 3., rework. u. exp. Edition (March 22, 2010): 292-294.
- ↑ Wüster, W, Crookes, S, Ineich, I, Mané, Y, Pook, CE, Trape, JF, Broadley, DG (2007) The phylogeny of cobras inferred from mitochondrial DNA sequences: Evolution of venom spitting and the phyleogeography of the African spitting cobras (Serpentes: Elapidae: Naja nigricollis complex). Molecular Phylogenetics and Evolution, 45: 437-453
literature
- Mark O'Shea: Venomous Snakes of the World. New Holland Publishers 2008; P. 73. ( Scan from Google Books )
- Johan Marais: Complete Guide To Snakes Of Southern Africa. Struik Publishers 2005; Pp. 110-113. ISBN 978-1-86872-932-6 ( scan from Google Books (incorrectly named) )
- Dietrich Mebs: Poisonous animals. A handbook for biologists, toxicologists, doctors and pharmacists . Wissenschaftliche Verlagsges. Stuttgart; 3., rework. u. exp. Edition (March 22, 2010): 292–294.
