Texas A&M University-Kingsville

MOMENT WITH AN EXPERT: 5 Things You Didn't Know About Snakes

KINGSVILLE - July 18, 2014

Contact: Adriana Garza-Flores
adriana.garza@tamuk.edu or 361-593-4979

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Dr. Elda Sanchez has dedicated her career to researching potential biomedical uses of the toxins in snake venom. She currently serves as assistant professor and Executive Co-Director of the National Natural Toxins Research Center—the only federally-funded Viper Research Center in the nation. Here she shares the answers to some of the questions she is asked about snakes most frequently.

Did you ever wonder why a snake flicks its tongue in and out and why its tongue is forked?  In order to detect prey or mates, snakes do a lot of their smelling with their tongues.  The tongue picks up scent particles in the air and the ground.  A special nerve-ending organ susceptible to smells called Jacobson’s organ, or vomeronasal organ, receives the scent particles from the tongue.  Nerves from the organ connect it to the olfactory lobe of the brain.  Particles captured on the tongue are passed through two small cavities on the roof of its mouth leading to the Jacobson’s organ. The forked tongue allows the passage of particle information through each cavity at the same time.

How do snakes deliver their venoms? Members of the Elapidae (e.g. cobras, coral snakes, taipans) and the Viperidae (e.g. rattlesnakes, copperheads, vipers) contain specialized venom fangs at the front of their mouths.  The fangs of the elapids are short and fixed and those of the vipers are long and hinged for folding when not in use.  The fangs are two hollow teeth, much like hypodermic needles, that fill with venom from two venom glands located on each side of the snake’s head.  Snake fangs are replaced continuously throughout a snake’s life which explains why snakes sometimes possess two fangs on a given side; however, only one set of fangs are functional at any given time. As one fang is shed, it is trapped in the fang sheath and at any time will fall off. This may explain “dry” bites, in which a snake will not inject venom or may inject very little when biting.  Approximately 50% of snakebites are “dry” bites.

Do venomous snakes capture all type of prey the same way? Venom is generally used the same way by all types of venomous snakes, to capture and digest.  Small and non-dangerous prey are struck and detained while the venom takes effect. Birds, , which can fly long distances before surrendering to the venom’s effect, are always detained.  Large prey, which could harm the snake while the venom takes full effect, are struck and then released, and the snake can then hunt down the dying prey with its tongue until the carcass is found.

Do all venomous snakes contain the same type of venom? Snake venoms contain many of the same components as human saliva, such as calcium, ammonia and magnesium as well as fats and mucus. In addition to these components, snake venom consists of dangerous molecules. Hemotoxins are molecules that attack the circulatory system and blood components, and neurotoxins are molecules  that attack the nervous system.  The hemotoxins can cause circulatory failure either through clotting (causing blockage of blood flow through the veins or arteries) or non-clotting (causing excessive blood loss).  The neurotoxins affect the nervous system controlling movement and breathing. In general, Viperidae venoms contain hemotoxins as their majority components, and Elapidae venoms are mainly neurotoxins. Hemotoxins are responsible for extensive bruising and tissue degradation whereas the neurotoxins cause paralysis. Nonetheless, venomous snakes can contain a mixture of both hemotoxins and neurotoxins in varying amounts.  It is also well known that venom even within the same species is different (i.e. one Southern Pacific rattlesnake can contain venom that is more potent than another individual Southern Pacific rattlesnake). These differences are contributed as a result of age or disparities in populations. In some cases, antivenoms are not capable of saving the lives of humans who have been envenomated by an individual snake whose venom of that species was used for the production of the antidote. This is why it is important to use venoms from various individual snakes of various geographical locations and ages when producing antivenoms.

Do the segments on the rattle found on rattlesnakes indicate the snake’s age? No, each segment represents a shed skin, and snakes may shed up to four or more times a year, and since the rattle is made of brittle material, it can easily be broken off.  Rattles are made of keratin, the same material found in our hair and nails. Therefore, rattles that contain more than 6 or 7 segments are rare in rattlesnakes found in the wild, but are often more common in those that are held in captivity.


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This page was last updated on: July 18, 2014