You are here:
The Elapidae ("cobra family": cobras, mambas, seasnakes and allies) consists of about 300 species in 61 genera, and includes some of the most dangerous snakes in the world. Most of these snakes are very fast and agile, and can be quite a handfull to work with. The Black mamba (Dendroaspis polylepis) for example, is the fastest snake in the world, reaching speeds of sometimes more than 10 miles per hour (4 - 5 meters per second). The Inland Taipan (Oxyuranus microlepidotus) is generally considered to be the most venomous snake in the world (drop for drop). Elapids have adapted to many different habitats, including borrowing and a marine environment (seasnakes). The fangs are positioned in the front of the upper jaw, and are relatively immobile (with exceptions in mambas (Dendroaspis), Taipans (Oxyuranus) and death adders (Acantophis)). Their sizes range from small (20 cm, Ogmodon) to immense (15 feet / 6 meters, king cobra).
The best known elapids are the cobras, which consists of 10 genera (Aspidelaps, Boulengerina, Dendroaspis, Elapsoidea, Hemachatus, Naja, Ophiophagus, Paranaja, Pseudohaje and Walterinnesia) and numerous species. All are found in Africa, with Naja (true cobras) ranging into Asia as well, Walterinnesia (desert black snake) ranging into Iran and Ophiophagus (king cobra) being fully Asian. Most are large snakes, (4 to 8 feet / 1.2 - 2.5 meters) with the king cobra being the largest, reaching 15 ft (5 m.), although these giant sizes are now rarely encountered in the wild, and most king cobras are between 8 and 12 feet (2 - 4 meters) long. Aspidelaps (dwarf cobras) Elapsoidae (gartersnakes) and Walterinnesia are the smallest genera, and don't usually grow bigger then 2 - 2.5 feet.
A characteristic of cobras is their fascinating hooding behavior, where they stand up and broaden their necks to impress, and hopefully scare off, potential attackers and predators. Everybody who has seen this behavior in real life, will affirm that this is spectacular behavior. it is often accompanied with loud hissing, and in the case of spitting cobras with multiple spits of venom aimed at the attacker. This behavior is especially astonishing in king cobras. Although their hood is not as broad as in their African cousins, they can stand up at impressive heights. Looking a king cobra almost straight in the eye face-to-face while just standing, is indeed a very impressive sight.
Seasnakes are elapid snakes that were once terristrial in nature. Two groups can be distuinguished: (i) one genus, Laticauda, which spends most of its adult life at sea but comes to the beach to lay eggs and bask (ii) the 'true' seasnakes, hydrophids, who spend all of their lives at sea and bear their young live. The latter group includes about 16 genera in 53 species. Laticauda and hydrophids represent two seperate invasions of the marine environment, since these two groups are not closely related in the elapid phylogeny. In both groups, their nearest sister-groups are terristrial. The hydrophids originated by an invasion of the marine environment by an ancestral Australian-Papuan terristrial elapid.
Seasnakes have many adaptations that enable them to survive marine environments. Where other snakes would die because of dehydration, seasnakes posses a salt-excreting gland under their tongue sheath that prevents this. It is thought that they drink some salt water, although it is much more likely that seasnakes drink the top layer of fresh water on the ocean after it has rained. Many zoos and private professional collecters have forgotten to provide their captive seasnakes with fresh water, which resulted in most not being able to keep their seasnakes alive. Another adaptation of seasnakes to life in the sea is the laterally compressed body and the flat 'fin-like' tail, that enables swimming. Except Laticauda, the seasnakes have also lost or greatly reduced ventral scales. These scales are necessary for terristrial locomotion.
They are spread across the pacific to the Western coasts of Central and South-America and south to New Zealand. None is kn own from the Atlantic Ocean, although the pelagic seasnake (Pelamis platurus) is a candidate for finding its way there.
Contrary to what many people believe, seasnakes do need to surface to breathe air. They have lungs, just as any other snake, and cannot stay under water for longer than 1 to 2 hours. They have modified lungs, that stretch almost the whole body, and are also able to take some oxygen from the seawater through their skin. Oxygen enters the body through tiny blood vessels that lie underneath the seasnakes' skin, and carbon dioxide diffuses out. Finally, their nostrils contain valves to prevent water from coming in when they are under water.
A widespread myth is that seasnakes have small mouths and not capable of biting humans, or biting through diving suits. This is wrong! Their mouths can open wide, as in other snakes, and enable them to swallow large fish whole. Another myth is that seasnakes have small fangs, but in fact the fangs can be just as large as other elapids. They are certainly capable of biting through most dive suits. The truth is, however, that most seasnakes are generally very timid creatures with a very curious nature. They will swim towards divers to satisfy this curiosity. Often they will go towards the goggles and look at it, it is as if they are able to see their mirror image. Most seasnakes won't bite, unless heavily provoked. Especially Laticauda has a reputation for being extremely docile.
As all other snakes, seasnakes need to shed their skin a few times per year. Laticauda does this on land, all others in the water. Seasnakes have heavily keeled scales, and they often rub their nooses against their own bodies to break the skin when they need to shed.
Mambas have a special place in my heart. As king cobras and taipans, mambas are very intelligent snakes. And they can be lethally fast, faster than any other snake in the world. They have a slim body, and move elegantly. Their fangs are rather large, and capable of some movement (rare among elapids). T Mamba venom acts really fast. In old days, the mortality rate of black mamba bites was 100%. African natives would not rarely cut off their finger immediately after being bitten by one. Honestly, this is not a bad idea if done (really) quickly. It off course depends on many other factors, like how far you are from a hospital. Nowadays we have relatively good antivenom available, so putting on a bandage would be a better idea.
There are 5 species of mamba: the black mamba (Dendroaspis polylepis), the Western green mamba (D. viridis), the Eastern green mamba (D. angusticeps) and two species of the Jameson's mamba (D. jamesoni). Except the black mamba, all are tree dwellers. The black mamba may reach 14 feet, and is the largest African venomous snake and the one to longest in the world (after the king cobra). It is a voracious snake, one that does not like to be caught. Understandably. Catching a black mamba requires lots of water, since you would be out of sweat in about 10 minutes. I consider the black mamba to be the most difficult snake in the world to catch, perhaps a shared first place with a coastal taipan (Oxyuranus scutellatus).
The other species of mambas are a bit more relaxed, but can also be very fast and highly dangerous. The Eastern green mamba is the most timid species of mamba.
Elapid venom primarily acts on the nervous system, causing rapid paralysis of skeletal and cardiac muscles in the thoracic cavity. These symptoms are caused by the post- and pre-synaptic neurotoxins. Paralysis of the respiratory system can occur within hours, and is preceded by other signs of neurological symptoms like ptosis (drooping of the eyelids). Other symptoms include dizziness, headaches, nausea etc.. Many elapid bites are painless, although not all. It is of uttermost importance to have access to artificial respiration quickly. Putting on a bandage quickly can slo be life saving. This bandage prevents the transport of the venom to the lymph nodes, where it will be taken up in the blood. People who had been bitten by very dangerous elapid snakes are known to have been symptom free for many hours because they wrapped on a bandage quickly. As soon as the bandage is removed, they may turn into shock. Therefore the bandage must only be removed slowly at the hospital, under careful monitoring, and with antivenom present.