The only Sri Lankan member of the reptile Family Boidae, the Sri Lankan Sand Boa (Gongylophis conicus brevis) is a small but stout species which only grows up to approximately 0.5 m in length. They are relatively shorter than the pythons and the females are generally larger than the males in body size.
Boas posses rudimentary hind limbs, the extremities of which are visible as claws-like processes on either side of the vent; and most members of the family lack labial pits in the lips and posses keeled body scales.
Sand Boas are viviparous – meaning, the females give birth to live young. Considered a nocturnal species, they are normally slow moving, very sluggish snakes. They are a terrestrial species, whose distribution is restricted to some coastal areas of the country (mainly in the semi arid zones), where it inhabits the scrublands and sand dunes.
Often mistaken at first glance for either the Indian python or the deadly Russell’s viper, this uncommon, non-venomous species can be found in the Yala coastal area.
Text reference: www.srilankanreptiles.com/Snakes/Boas.html