The Cold Blooded News

The Newsletter of the Colorado Herpetological Society

Volume 28, Number 2; February, 2001

Venomous Snakes, Pick Your Poison

By Ed Ferrer

Reprinted from The Monitor, the newsletter of the Hoosier Herpetological Society, Vol.11, No.11, November 2000.

Snakes, as a group, are often feared by the general public. One of the "reasons" these often irrational people give when asked about their fear of snakes is that they are afraid any snake they see might be "poisonous". Whenever I am showing my snakes in a program, someone will always ask me if any of my snakes are "poisonous". For the record, if something is "poisonous" it is taken orally and if it is "venomous" it is injected. Therefore, snakes that can inflict a fatal or damaging bite should be referred to as "venomous" and not "poisonous". Such widespread fear and misinformation often leads to the killing of any snake on sight by the general public due to their intolerance brought on by fear and ignorance. This is truly unfortunate because venomous snakes are some of the most unique and fascinating members of the animal kingdom. Most herpetologists consider the venomous snakes to be the most highly evolved and advanced of all snake species. The venomous snakes can be divided into three distinct groups based on the mechanism for injecting venom. Let's take a closer look at these special serpents.

The first group I would like to view is often overlooked when the topic of venomous snakes is discussed. This group is known as the "opisthoglyphs" and includes all snakes that are rear-fanged. The rear-fanged snakes are often forgotten because many of these species are not very dangerous to humans. For example, members of the genus Heterodon (hognose snakes) have enlarged rear teeth designed for the purpose of "deflating" frogs and toads, produce a mildly toxic venom that is basically harmless to humans. (They almost never bite when disturbed but instead go into a threat display and then play dead.) Some species of night snakes from the genus Hypsiglena have a toxic saliva that seems to be very effective on their prey of choice, primarily lizards, but is basically harmless to us. However, this rear-fanged group includes the boomslang, Dispholidus typus, one of the deadliest snakes in the world.

The proteroglyphs have fixed front fangs. This group contains some of the deadliest snakes in the world. Included in this group are the cobras, mambas, and coral snakes. A few snakes in this group have fangs that have small discharge orifices facing frontward through which two thin streams of venom can be projected toward its enemies. The venom from these spitting cobras has caused permanent blindness in some of its victims. Sea snakes are also included in this group and have some of the most toxic venom (drop for drop) in the world. The king cobra, Ophiophagus hannah, is regarded by many experts to be the most intelligent of all snakes. Evidence of their advanced development is their habit of often remaining with one mate for life, building a nest for their eggs, and guarding the mound-like nest site against possible predators. The king cobra produces an incredibly virulent venom that can easily kill a person. In fact, it has been recorded that one king cobra even bit and killed an elephant!

The third group, the solenoglyphs, are often regarded as the most advanced of the venomous snakes because of their unique envenomating apparatus. They possess two large, curved fangs in front of their mouths that spring forward when the mouth is opened and fold back into small cavities in the roof when the mouth is closed. These fangs can be operated independently, especially when used "pulling" a prey item downward into its gullet. These fangs are shed every now and then and are replaced by newer ones located just behind the current ones. These snakes are thought to be the fastest-striking of all venomous serpents. They don't grab a prey as much as they "stab" them. Often they can lung, strike, and resume a defensive posture in one swift motion before the victim even realizes what has happened. This groups includes rattlesnakes, copperheads, cottonmouths, vipers, and adders.

These venomous snakes represent the very pinnacle of snake evolution. These often misunderstood creatures are superbly adapted for success in the natural world. Since the venom they possess is primarily used to subdue their prey, they usually try not to waste it. In fact when encountered by humans, they will usually retreat slowly if given a chance. If cornered, they may strike as a warning. Often these strikes are what is known as "dry bites", meaning that venom is withheld. However, there are no guarantees when these serpents are encountered in the wild. If you are bitten, you should go immediately to the closest hospital for treatment. DO NOT TRY FIRST AID REMEDIES! Above all we should remember that these shy, reclusive creatures hunt mostly mice, rats, and other rodent pests that do much more damage to us than the occasional snake bite. Most of these amazing reptiles are becoming endangered or threatened because of misguided extirtation efforts and habitat destruction. Hopefully we can learn enough about these fascinating serpents to appreciate and respect their place in nature before they are lost forever.

Reference: Venomous Snakes of the World. W.P. Mara, T.F.H. Publications, Inc. 1995.