Jameson's mamba

Jameson's mamba was first described as Elaps jamesoni in 1843 by Thomas Traill, a Scottish doctor, zoologist and scholar of medical jurisprudence. The specific epithet is in honour of Robert Jameson, Traill's contemporary and the Regius Professor of Natural History at the University of Edinburgh where Traill studied. In 1848, German naturalist Hermann Schlegel created the genus Dendroaspis, designating Jameson's mamba as the type species. The generic name is derived from the Ancient Greek words (, 'tree') and ( 'asp'). The genus was misspelt as Dendraspis by French zoologist Auguste Duméril in 1856, and went generally uncorrected by subsequent authors. In 1936, Dutch herpetologist Leo Brongersma corrected the spelling to the original. In 1936, British biologist Arthur Loveridge described a new subspecies D. jamesoni kaimosae, from a specimen collected from the Kaimosi Forest in western Kenya, observing that it had fewer subcaudal scales and a black (rather than green) tail. Analysis of the components of the venom of all mambas places Jameson's mamba as sister species to the western green mamba (Dendroaspis viridis), as shown in the cladogram below. ==Description==

Jameson's mamba is a long and slender snake with smooth scales and a tail which typically accounts for 20 to 25% of its total length. The total length (including tail) of an adult snake is approximately . It may grow as large as . The general consensus is that the sexes are of similar sizes, although fieldwork in southeastern Nigeria found that males were significantly larger than females. Jameson's mamba has between 15 and 17 rows of dorsal scales at midbody, 210 to 236 () jamesoni) or 202 to 227 ventral scales ( kaimosae), 94 to 122 ( jamesoni) or 94 to 113 ( kaimosae) divided subcaudal scales, and a divided anal scale. Its mouth is lined with 7 to 9 (usually 8) supralabial scales above and 8 to 10 (usually 9) sublabial scales below, the fourth ones located over and under the eye. Its eyes have three preocular, three postocular and one subocular scale. ==Distribution and habitat==

Jameson's mamba occurs mostly in Central Africa and West Africa, and in some parts of East Africa. Found in primary and secondary rainforests, woodland, forest-savanna and deforested areas at elevations of up to high, Jameson's mamba is an adaptable species; it persists in areas where there has been extensive deforestation and human development. It is often found around buildings, town parks, farmlands and plantations. Jameson's mamba is a highly arboreal snake, more so than its close relatives the eastern green mamba and western green mamba, and significantly more so than the black mamba. ==Behaviour and ecology==

Jameson's mamba is a highly agile snake. Like other mambas it is capable of flattening its neck in mimicry of a cobra when it feels threatened, and its body shape and length give an ability to strike at significant range. Generally not aggressive, it will typically attempt to escape if confronted. Jameson's mamba is oviparous; the female lays a clutch of 5–16 eggs; in Nigeria laying was recorded from April to June, and most likely soon after November in Uganda. ==Venom==

Jameson's mamba is classified as a Snake of Medical Importance in Sub-Saharan Africa by the World Health Organization, although there are few records of snakebites. Snake bites are rare in cities but more common in forested areas in countries such as the Democratic Republic of the Congo; the country's poor infrastructure and lack of facilities render access to antivenom difficult. Like other mambas, the venom of the Jameson's mamba is highly neurotoxic. and are thought to cause symptoms such as sweating. Unlike that of many snake species, the venom of mambas has little phospholipase A2. Treatment The speed of onset of envenomation means that urgent medical attention is needed. Tetanus toxoid is sometimes administered, though the main treatment is the administration of the appropriate antivenom. Trivalent and monovalent antivenoms for the black, eastern green, and Jameson's mambas became available in the 1950s and 1960s. ==See also==