Why are some snakes deadlier than others?

Why venoms vary so much in their ability to kill or incapacitate potential prey animals?

Rattlesnake
Image: Pixabay

Snakes are infamous for having powerful venoms, a reality that makes them deadly predators and also horrible. Be that as it may, a few species, for example, cobras, boomslangs and rattlesnakes have undeniably more venom than they evidently require—in a single hold of venom, they can possibly kill thousands of their prey animals and a few grown-up people.

Be that as it may, not all venomous snakes are so dangerous. For instance, the marbled sea snake has just a little measure of exceptionally powerless venom, making it viably innocuous to anyone.

Why venoms differ so much in their capacity to kill or incapacitate potential prey creatures has long baffled scientists, with a few contending theories proposed as clarifications.

In a new study by that includes international collaboration led by scientists from the National University of Ireland, Galway, The University of St Andrews, Trinity College Dublin and the Zoological Society of London, scientists uncovered why the venom of some snakes makes them so much deadlier than others.

They compared records of venom potency and quantity for over 100 venomous snake species, ranging from rattlesnakes, cobras and the tree-dwelling boomslangs of Africa to sea snakes and burrowing asps. The came up with strong evidence that venoms have evolved to be more potent against animals that are closely related to the species that the snake commonly eats.

The research also showed that the amount of venom a snake has depends on both its size and the environment it lives in.

Dr. Kevin Healy, who conducted the research at the University of St Andrews explained, “These results make sense from an evolutionary viewpoint as we expect that evolution will have shaped venoms to be more efficient at killing the prey animals they are most often the target of the venom. You won’t find many mice in the sea so we wouldn’t expect a sea snake to evolve venom that is more effective at killing mice than fish.”

Associate Professor in Zoology at Trinity College Dublin, Dr. Andrew Jackson said, “Like all substances venom is dosage-dependent. Even alcohol, coffee and water can be toxic at high enough volumes so we needed to consider how much venom different species of snake produce and store in their venom glands. We found that big terrestrial species have the most venom, while smaller tree dwelling or aquatic species had the least. 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.”

Dr. Chris Carbone of the Institute of Zoology in the Zoological Society of London said, “Snakebites are a major health concern worldwide, with 2.7 million cases each year. Understanding how venom evolves may help us better identify the risks to humans from different snake groups, and also potentially from other venomous animals such as spiders, scorpions, centipedes, and jellyfish.”

The results of the study also have the potential to aid in our understanding when it comes to human snakebites.

Dr. Healy added: “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. 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.”

The study is reported in the journal Ecology Letters.