Isabel Cantú
For humans, saliva helps us break down our food, as do our teeth, and moisturizes our mouths. Now imagine if that saliva was toxic, a unique and deadly mixture capable of paralyzing someone if you were to bite them. You can release it through hollow sockets in your teeth or have fangs equipped with grooves that transport it for you. This is what has evolved in venomous snakes and is the reason why so many are feared around the world, sometimes having a few drops of their venom marked as being lethal enough to kill one-hundred people. It is easy to write off venom as just being dangerous, but why is it so dangerous? Understanding snake venom makes snakes all the less intimidating and all the more awe-inspiring.
Snake venom can differ subtly depending on the snake you study, and rightfully so. Venom’s composition varies from species to species, snake to snake. At the basic level it’s an uneven liquid mixture of different enzymes, lipids, metal ions, and proteins. It is certainly not the most seamless combination of ingredients, but it provides a basis for some of the most deadly snake venoms in the world. Potent venoms make their move on individual cells, chewing off cell membranes and disrupting the blood clotting process while breaking up communication between nerve tissues. One neurotoxin in particular, taipoxin, is what makes an Inland Taipan snake’s venom lethal enough to be crowned the unfortunate title of “most toxic.” It is able to disrupt motor neuron functions to the point where anything bitten will face asphyxiation, dying under an hour—this time limit applies to bitten humans as well, although the symptoms are slightly different.
An inland taipan, one of the most venomous snakes in the world
It is a common idea that all snakes push their venom through their hollow fangs, where the venom then pours into a bite and into the bloodstream of an animal or person. This is how some snakes deliver venom, but it is definitely not the most popular nor the most effective method. Many snakes have fangs that are not just curved teeth with a smooth outer surface—the fangs have grooves. These are what should really be feared much more than the teeth, as the high surface tension of the venom keeps it from going anywhere but down the tooth and towards the bite. If it weren’t for this venom slide, it would be possible to brush away the venom and prevent it from entering the bloodstream. Once it does reach the tissues, it is readily absorbed and begins to terrorize the cells.
Snake venom did not actually evolve from a snake ancestor, but rather from a lizard ancestor before snakes evolved from them. This most likely took place around 200 million years ago when the need to immobilize prey before it could run away was the key to venom evolution. So snakes took the idea of venom from lizards and put their own malicious spin on it, turning it into the horrific concoction that it is today. Yet we only know so much about venom despite understanding its origins—the in-betweens of what exactly venom is and how it can be used are foggy. We know the bulk about venom from studying only three snake families: Elapidae, Hydrophiidae, and Viperidae, despite this only being a fraction of the total number of venomous snake families.
Rattlesnakes are one such snake with hollow fangs to force venom into a bite
For what are easily some of the most beautifully decorated reptiles, venomous snakes are undoubtedly not the kind of creature you want to wind up face-to-face with. Their venom ranges from mild to extremely lethal, all beginning with a base mixture of enzymes and proteins. To think that venom can change not only between species, but between individual snakes in the same species, goes to show that it is not as straightforward as many might think. Venom can switch from viscous to a smooth liquid going down the grooves of a fang to a painful bite, and may even include neurotoxins like taipoxin that increase its potency. The key to precaution is to understand the ins-and-outs of what venom is and how it can affect your cells, tissues, and organs. Despite the fact that we pull the majority of our knowledge from only three snake families, it is enough to realize that snakes have left a creative and devilish mark in the world of venom.
Works Cited
Image Credit:
https://commons.wikimedia.org/wiki/File:Oxyuranus_microlepidotus_IMG_5067_Inland_taipan.jpg , License: Creative Commons Legal Code, Author: Bjoertvedt
https://upload.wikimedia.org/wikipedia/commons/a/a5/Timber_Rattlesnake_045.jpg , License: Creative Commons Legal Code, Author: Ltshears
Educational Questions:
Q. What exactly is venom?
A. In simplistic terms, venom is a mixture of proteins, metal ions, enzymes, and lipids, altogether a liquid that is the basis for the deadliest venoms we know of.
Q. Do snakes deliver venom to prey through their hollow fangs?
A. This is how some snakes will release venom, but it’s not effective given how the venom is not guaranteed to make it into the bloodstream of prey. Instead a lot of snakes have grooves on their fangs that keep the venom from going anywhere but into a bite.
Q. How did snakes evolve to have venom?
A. Most likely from a lizard ancestor that lived about 200 million years ago, when it was necessary to develop a way to immobilize prey before they could escape.