Medically Significant Bites by “Colubrid” Snakes - "Venomous" Bites from Non-Venomous Snakes - page 244

(A)
(B)
Plate 4.95 (A and B) Eastern green or common mamba; Groen Mamba, Ilumangiu
( Dendroaspis angusticeps ) . The African genus Dendroaspis contains four species of fast-moving,
distinctive elapids. Dendroaspis angusticeps is medically important throughout its range (mid-East
Africa-eastern South Africa), but is a shy and retiring species that attains an average adult length
of approximately 1.80 m. However, its bite can be fatal; numerous life-threatening and fatal cases
have been well documented. Its venom (i.p. murine LD 50 ranges between 0.25 and 0.70 mg/kg)
has been thoroughly studied, and several three-finger-fold postsynaptic muscarinic neurotoxins/
α 2 -adrenocepter antagonists, natriuretic peptides as well as novel potassium ion channel/mixed
agonist/antagonizing toxins (dendrotoxins that sequentially suppress, then enhance acetylcholine
release, thereby excessively facilitating and ultimately “exhausting” synaptic transmission
resulting in paralysis), acetylcholinesterase inhibitors (fasciculins), and other components have
been characterized. These toxins are useful biomedical tools and may hold some potential as
therapeutics. Although these snakes have a distinct appearance, a casual observer may mistake
(especially from a distance) for D. angusticeps other similarly colored ophidian species such as the
green or “jungle phase” hazard level 1 colubrid, D. typus (compare Plate 4.95B with Plate 4.20A-
D), or one of the medically unimportant arboreal colubrines, such as the African green, bush, forest,
wood, or tree snakes, Philothamnus spp. (approximately 18 species). It is worth noting that one of
the other members of the genus Dendroaspis , the black mamba ( D. polylepis ), has been subjected
to much misinformed sensationalism. Although the body color of this snake is variable, it typically
is gray, and the common name is derived from the dark color of the buccal mucosa. It is a large
species (occasionally exceeding 3.5 m) with highly toxic venom (equal to the common Asian cobra,
Naja naja ; the i.p. murine LD 50 averaging 0.30 mg/kg) can be aggressive if molested; fatal bites are
well documented. The venom apparatus of these snakes is representative of the “proteroglyphous”
condition with fixed, erected, canaliculated fangs.
Photos copyright to Julian White.