Intraspecific variation in the venom composition of wild Vipera berus from two English populations

Intraspecific variation in snake venom composition (protein and peptide toxins) has been documented on numerous occasions, predominantly within the families Viperidae and Elapidae. Known sources of this variation include: snake age, size, sex, feeding ecology, population geography and abiotic ecological factors associated with changing seasons. Such variation has been studied before in venoms of the European adder (Vipera berus) from Eastern European and Russian populations. However, the venoms of wild, British V. berus and their potential variation have never been studied. Two potential sources of British V. berus venom variation were investigated (differing population geography/ecology and snake sex). The two ecologically distinct wild V. berus populations sampled in this study are located in the English counties of Staffordshire and Essex. Reverse Phase High Performance Liquid Chromatography (RP-HPLC) analysis was used in isolation to separate V. berus venoms into their respective components. Venom composition data analysis involved a combination of Multivariate Analysis (MVA) and hypothesis testing. Subsequent results revealed that venom components varied between all samples. Based on the MVA, some of this venom component variation is attributed to potentially differing population ecology. Hypothesis testing (nonparametric Mann Whitney U test) revealed that the abundance of venom components varied significantly with V. berus sex. Experience gained during this study’s venom collection field work and the results of RP-HPLC analysis will contribute to further research. This includes the search for pharmacologically active venom components, not only in V. berus but also other snake species. Furthermore, this study contributes to addressing whether or not there is the need for locality specific V. berus antivenom development. Knowledge of snake venom composition intraspecific variation being fundamental to antivenom design, production and administration.