Thursday, June 10, 2010

Introduction


In Sri Lanka majority of land snakes are non-venomous & do not have fangs, venom glands or venom. Venomous snakes are distinguished from non-venomous species by the presence of a pair of cephalic glands, which produce venom and enlarged Maxillary teeth called fangs. The snake bite venom contains powerful tissue destroying agents and toxins which are mainly directed against nerve and vascular tissue.

Classification of snakes on their venom toxicity

Highly venomous
Makes the person severely ill(systemic effects), Deadly.
Fangs are on the front of the upper jaw
Eg:All sea snakes in SL coastal waters, 2 Kraits(Common krait/Magamaruwa/Thel Karawala & Sri Lanka krait/Mudu Karawala), Cobra(Naya), Russell’s viper(Thith Polanga), Saw scaled viper(Weli Polanga) & Hump nosed viper(Polon Thelissa/Kunakatuwa).

Moderately venomous
Moderate systemic effects, rarely leads to death.
Fangs are on the front of the upper jaw
Eg: Four species of pit vipers including Green Pit viper (Pala Polanga)

Mildly venomous
No systemic effects may cause local adverse effects (wound), not deaths.
Fangs are on the back of the upper jaw
Eg: 12species of Colubridae family snakes. group includes two Ahaetulla species(Vine snake), 5 Boiga species (Mapila in Sinhala/Cat snakes), Dog faced water snake (Kunu diya kaluwa), Blossem krait(Nihaluwa), Ornate flying snake(Malsara), Sri lanka flying snake(Dagara danda) and Glossy marsh snake(Prevostage Diyabariya)

Non venomous
Majority in Sri Lanka falls in to this category
Do not have fangs
Eg: Rat snake(Geradiya), Ceylon Wolf snake