Abstract:
The Russell‘s viper, Daboia russelii has a relict distribution over large areas of Indian Sub
Continent, Taiwan and the Lesser Sunda islands. Russell‘s viper is distributed with varying
densities and occurrence throughout many natural and modified habitats in Sri Lanka. Bite of
this species is associated with a high incidence of morbidity and mortality in Sri Lanka. There
is scanty of information available about Russell‘s viper in Sri Lanka. Thus, preliminary study
was carried out using clinical data obtained from the twenty eight patients admitted due to
Russell‘s viper bite in General Hospitals in the Gampaha District. Further, thirty five DNA
samples were collected from the tail tip of specimens of the Russell‘s viper from Gampaha,
Kandy, Rathnapura, Galle, Anuradhapura and Kurunagala districts for molecular
phylogeny. Then fragment of mtDNA sequencing fragments of cytochrome b genes were
amplified. PCR and products were subjected. DNA sequencing for molecular analysis using
raxmlGUI software.
Results revealed that the clinical features following Russell‘s viper envenomation are
follows; local swelling 86%, local necrosis 7%, coagulopathy 75%, neurotoxicity 32%,
nephrotoxicity 14% and cardiac effects 3%. Mortality of Russell‘s viper bites are caused by
complications like renal failure, neurotoxicity, respiratory failure, disseminated intravascularcoagulation,
heart failure and other cardiotoxic effects.
Alignment of Sequences of Cytochrome-b gene by maximum likelihood analysis
revealed that two strongly supported monophyletic clades corresponding to Sri Lanka and the
Indian subcontinent. However, Sri Lankan Russell‘s viper was nested within the clade of
Indian Russell‘s viper group. There was genetic divergence (2%) between the Indian clades
and the Sri Lankan clade. However, these haplotypes do not show any geographically
significant pattern. Thus, it could be suggested that Indian and Sri Lankan Russell‘s viper are
genetically closely related and origin may be India or Sri Lanka. Further studies are being
carried out on morphometric, molecular taxonomic and venomous differences in different
geographic location within the Sri Lanka and Asian region.
