Black-necked spitting cobra
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| Black Necked Spitting Cobra | |
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| File:Naja Nigricollis.jpg | |
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| Species: | N. Nigricollis
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| Binomial name | |
| Naja Nigricollis | |
- Common names: Spitting Cobra, Black Necked Spitting Cobra, Zebra Spitting Cobra (subspecies), Black Spitting Cobra (subspecies)
Naja nigricollis is a species of spitting cobra found in Sub Saharan Africa. It is feared throughout its range and has the capability of spraying venom at attackers as a defensive mechanism. There are three subspecies, as well as the nominate subspecies described here.
Description
Naja nigricollis is a long medium-bodied snake with a moderately distinct head; the shape of the head is due primarily to the two large venom glands found on each side of the head. The snake is generally grey with a solid black hood and head. The snake can also be solid black with red blotches on the hood. There are 21-23 dorsal scales at the mid-body, 182-196 ventral scales, and 54-66 subcaudal scales. This snake generally grows to a length of 120-220 cm but has been known to attain a length of over 280 cm. These sizes are subject to trends based on geographic location and subspecies. The subspecies N. n. nigricincta, also known as the Zebra Spitting Cobra, is given its name due to the dark crossbars that run the length of the snakes body. The subspecies N. n. woodi is solid black and is found only in the desert areas of Southern Africa. Both of the non-nominate subspecies are smaller than N. n. nigricollis, both subspecies average adult lengths of less than 150 cm. (more...)
Venom
The venom of Naja nigricollis is characteristic of the African spitting cobras. It retains the typical elapid neurotoxic properties while combining these with cytotoxins. This snake is potentially lethal and has been responsible for numerous human fatalities. Bite symptoms include severe external hemorrhaging and tissue necrosis around the bite area. Death generally occurs due to asphyxiation due to paralysis of the diaphragm. The murine LD50 of Naja nigricollis is 2 mg/kg SC and 0.03 mg/kg IV. The average venom yield of this snake is 150-350 mg.
Behavior
Unlike other snakes, Naja nigricollis can be either nocturnal or diurnal depending on the time of year, geographic location, and average daytime temperature. This adaptability allows the snake to better regulate its body temperature (important for a cold blooded animal) and to gain access to the most abundant food sources of a particular area. Naja nigricollis feeds primarily on small rodents such as rats and mice, but will also eat lizards and other snakes. It is preyed upon by numerous species of predatory bird, such as the secretary bird. Naja nigricollis is also a frequent target of the Banded Mongoose, which uses its superior speed and reflexes to attack and kill the snake.
This snake, like other spitting cobras is known for its ability to project venom at a potential threat. The venom is an irritant for the skin and eyes. If venom enters the eyes, symptoms include extreme burning pain, loss of coordination, partial loss of vision and permanent blindness. Naja nigricollis is known for its tendency to liberally spit venom with only the slightest provocation. However, this aggressiveness is counterbalanced by the fact that Naja nigricollis is less prone to bite than other related species.
This species is not often found in captivity, and wild caught individuals are generally nervous and prone to spitting. Captive bred animals tend to be much more docile and calm when compared to their wild caught counterparts. The keeping of this species should never be attempted by anyone without the proper education and experience.
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Taxonomy
| Subspecies | Common name | Geographic range | Regional Differences |
|---|---|---|---|
| N. n. nigricollis | Black Necked Spitting Cobra | Eastern Africa in Tanzania, Kenya, Uganda, Burundi, and Rwanda. South Western Africa in South Africa, Namibia, and Angola. | The nominate subspecies. |
| N. n. nigricincta | Zebra Spitting Cobra | Central and Northern Namibia and Southern Angola. | Grey brown, yellow, or pink with dark bands from head to tail. |
| N. n. woodi | Black Spitting Cobra | Central and Western Namibia, South Africa (Cape Province). | Solid black, or grey body with black hood and head. In some cases it is outwardly identical to N. n. nigricollis and can only be distinguished by size and range. |