Elapids – An Introduction to the Family Elapidae and the Genus Naja
The Elapidae are certainly one of the most interesting families of snakes . Some of the most iconic and feared snake species, like the cobras, king cobras and mambas belong to this family.
Elapids are generally long and slender snakes and they are all truly venomous. Their head is usually not visibly separated from their body and they are easily mistaken for non-venomous colubrid snakes.
In this article, I want to introduce you to this fascinating family of snakes and tell you everything you need to know about them. This will include a detailed description of their classification, venom apparatus and venom composition and toxicity. I will also introduce the most fascinating elapid genus, which are the cobras.
Classification and basic Information
The Elapidae are the largest species complex of “true” venomous snakes. By “true” venomous snakes, all non-rear fanged venomous snakes are meant. Of course, rear fanged venomous colubrids are also often highly venomous snakes but they lack a sophisticated venom delivery system which is why they are classified differently.
Currently, there are about 325 species and 61 genera recognized in the two families of the sea snakes (Hydrophiidae) and the land-based Elapids (Elapidae). Although they are taxonomically quite different, the Hydrophiidae and Elapidae were originally classified as one family and are very simlilar.
Elapids are very active snakes and can often be seen hunting for their prey during the day. Compared to viper, they are more defensive, but also more predictable since their active body langue tell you how the snake feels. They may not have such advanced Venom delivery mechanisms like the Viperidae, but they do not need it.
Elapids will actively look for prey and sense their presence with the flickering tongue, often ending up chasing their prey. After striking, Elapids usually hold on to their victim and sometimes start swallowing while its still alive. Their fast acting, potent venom makes in impossible for the victim to defend itself.
Elapids are front fanged venomous, or proteroglyphous snakes. Proteroglyphous teeth means that their venom fangs are positioned in the front of their mouth and that they are, unlike a viper tooth, fixed and cannot be folded back. This also means that the fangs have to be very short, often no longer than half a centimetre. The fangs are formed like an injection needle with a small hollow duct connected to the venom gland.
Because of their short teeth, some people often question whether elapids can even pierce the skin of their prey enough for the venom to reach they preys internal system or bite through something like a jacked. The answer is no and yes, Elapids can indeed easily bite through a jacked. Just pierce your jacked with a short needle, it is almost the same and will get almost anywhere. And no, Elapids may not be able to sink their teeth in as deep as Vipers, but they do not need to reach the blood stream or tissue below the skin since their venom composition is different and targets different bodily systems. Sometimes, all it takes is a scratch for the venom to reach exactly the places it has to reach – your lymphatic system just below the skin. You may not even realize that the deadly toxins have entered your body…
Some elapids on this planet are among the deadliest creatures alive. Why these snakes have developed such incredible potent toxins remain an evolutionary riddle. But we do know quite a lot about the composition and effects of Elapidae envenomation, although we are still just scratching the surface of this research area.
For the most part, Elapidae venoms target the nervous system and neuron junctions to efficiently shut down the communication in their victims’ body. Some venoms may include hemotoxic factors, but unlike viper toxins, these snakes almost never cause necrosis, haemorrhages or severe tissue damage.
Elapid venom travels at first through the lymphatic system, which is located directly underneath the skin, before it enters the blood stream. Their venom also consist mainly of Enzymes such as Kunitz peptides, Acetylcholine inhibitors (Acetylcholinesterase) and alpha – and beta – neurotoxic Phospholipases A1 and A2. The largest group is probably made of neurotoxic three-finger peptides, which efficiently shut down the preys’ nervous system. An elapids Victim may die of shock, complete cardiac arrest due to flaccid paralysis or shut down of nervous system.
Neurotoxic Phospholipases A1 and A2
These enzymes induce nerve cell damage by binding irreversibly to the motor nerve terminals of the victims leading to impaired or completely inhibited release of the neurotransmitter acetylcholine. This depletion of transmission will then quickly lead to the complete degeneration of the nerve terminal, which will induce flaccid paralysis and cardiac arrest in the bite victim. The generation of the terminal occurs in three steps; first, when the enzyme binds to the terminal the release of acetylcholine is stopped. Second, the enzyme induces a sudden overflow of the neurotransmitter which is followed by complete inhibition of the neuromuscular junction.
Neurotoxic three finger toxins
This complex group of enzymes get their name from their physical structure which resembles a hand with three fingers. This toxin also messes up the release of acetylcholine and other neurotransmitters, but in a slightly different manner. On the one hand, they can bind to the peptide acetylcholinesterase, which is responsible for regulating acetylcholine release, causing a huge overflow of nerve stimulation which leads to spastic paralysis, a condition where the victims’ muscles start twitching uncontrollably. On the other hand, these enzymes may also act as beta-neurotoxic neurotransmitter inhibitors, which leads to similar effects as the phospholipase envenomation.
Now I want to introduce the three most interesting Elapidae genus in my opinion which are the cobras.
Cobras are among the most feared and worth-shipped creatures on earth. In India and Indonesia they are worth-shipped as gods or holy animals, while they are feared for their hoods and attitude all over the rest of the world. I believe that all together, they are just still very misunderstood and fascinating animals. The genus of true cobras goes by the Latin classification Naja and includes currently 36 species (constantly changing). Contrary to popular believes, the King Cobra (Ophiophagus hannah) is actually not a true cobra. It is called the King Cobra because it behaves similarly and feeds on other snakes, including other cobras.
The cobras hood is iconic all over the world. However, few people actually understand what it means. Cobras hood as a defensive method to avoid biting because venom production is energy consuming.
A snake will have to increase it metabolism for up to 20% to refuel their venom gland while your only speed up your about 3% during heavy exercisisng. So, the snakes do not want to waste their precious venom on some stupid attacker, which is why it spreads the skin around its neck to intimidate the opponent. It wants to bring across a message, namely that it is larger that it actually is and fierce and venomous. It wants to intimidate its opponent enough to scare him off without a bite.
Sadly, many snake charmers use this defensive behaviour for showman purposes. Snakes do not have outer ears, which means the animal is completely unaware of the flute music playing but just provoked by the movement of the flute and put in distress. Many snakes are defanged cruelly or get their mouth stitched up to make them harmless. Snake charming is an incredibly cruel activity and does only harm the animal in many ways.
In my opinion, spitting cobras are some of the most fascinating animals on this planet. They have developed a completely different defensive strategy which is still and evolutionary mystery.
Unlike most other elapids, their fangs have an enlarged and elongated opening which enables them to spray their toxins out of their mouth in a controlled stream. This occurs with incredible accuracy; spitting cobras can hit their opponents’ eyes precisely from up to 5m away, inducing incredible pain and partial blindness which enables the snake to escape.
When spitting cobras are confronted, they will first hood like all other cobras and warm their opponent but they are far less tolerant – get too close and you will experience pain like you never have before. Some African spitting cobra species are known for being exceptionally defensive and aware, sometimes not even bothering to hood before they used their incredible defence.
Because they use their venom for such a special purpose, their venom composition has evolved in a slightly different direction. Although they are still mainly neurotoxic, their venom includes some peptide commonly found in vipers which induce cytotoxicity and incredible pain trough severe tissue damage in the eyes of the attacker. It is also evolutionary evidence for the defensive use of venom in snakes.
I hope you enjoyed this short introduction to this fascinating family of snakes. If you are interested in further information on this topic, your should check out my “Venomous Snakes” section or head to the “Venomous Snakes Literature” reviews and get yourself a lot of first hand information and knowledge from experts.
If you are interested in my sources, click HERE!