Deadliness of snake venom linked to diet
Diet may decide the deadliness of a snake’s venom, according to research led by Irish scientists.
The researchers from NUI Galway and Trinity College Dublin were part of an international team. Their work could contribute to a greater understanding of the dangers of snakebites (2.5m people a year are bitten).
Their study, published today in the Ecology Letters journal, examined what affects the potency of the venom in different species of snake. The aim was to answer why some like cobras, boomslangs, or rattlesnakes have the potential to kill thousands of their prey or several humans, while others are effectively harmless to mankind or other relatively large animals.
The findings, from analysis of 102 species, suggest that the answer may lie in what a particular type of snake likes to eat, as the potency of snake venom was discovered to be prey-specific.
There was strong evidence that venoms have evolved to be more potent toward animals that are more closely related to the snake’s diet. For example, a species like the aquatic coral snake, which mainly eats fish, was most potent when measured on fish and lowest when measured on mice.
The study was part-funded by Science Foundation Ireland and a Higher Education Authority doctoral studies programme for earth and natural sciences.
Its lead author, NUI Galway lecturer, Kevin Healy, said the research could also help to predict the potency of venoms in species that have yet to be tested. It might also help pinpoint potentially useful healthcare applications.
“The next step is to see how well this model may predict the potency of venoms in groups that have yet to have their venoms tested,” said Mr Healy, who was at University of St Andrew’s, in Scotland, when the research was carried out.
“By using ecological and evolutionary data for available species, we may be able to use our approach as a tool to identify other species, which may have properties in their venoms that are useful for biomedical purposes, such as drug development,” he said.
The regularity with which a species encounters its prey was also highlighted by the researchers, who suggest this is a reason why the amount of venom produced and stored by each snake type can vary so widely.
“We found that big terrestrial species have the most venom, while smaller, tree-dwelling or aquatic species had the least,” said Andrew Jackson, associate professor in zoology at Trinity College Dublin.
“This difference may be due to how often a snake encounters its prey in these different environments, with terrestrial species requiring a larger reserve of venom to take advantage of the rarer opportunities to feed,” he said.
