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Reptiles Guide

Elapids

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Elapidae
Egyptian cobra, Naja haje
 
Egyptian cobra, Naja haje
Scientific classification
Kingdom: Animalia
 
Phylum: Chordata
 
Subphylum: Vertebrata
 
Class: Reptilia
 
Order: Squamata
 
Suborder: Serpentes
 
Family: Elapidae
Boie, 1827

The Elapidae, or elapids, are a family of highly venomous snakes found in tropical and subtropical regions around the world, including the Indian Ocean and the Pacific. They are characterized by possessing a set of hollow, fixed fangs through which they inject venom, and come in a wide range of sizes, from only 18 cm (Drysdalia) up to 6 m in length (Ophiophagus). This group is currently comprised of two subfamilies.

Contents

Description

Outwardly, terrestrial elapids look similar to the colubridae: almost all have long and slender bodies with smooth scales, a head that is covered with large shields and not always distinct from the neck, and eyes with round pupils. In addition, their behavior is usually quite active and most are oviparous.

Sea snakes, which are also elapids, have adapted to a marine way of life in different ways and to various degrees. Characteristics can include laterally compressed bodies, rudder-like tails for swimming, the ability to excrete salt and give birth to live young (ovoviviparous). Some genera, including Hydrophis, have ventral scales that are much reduced in size. Others, like the olive sea snakes (Aipysurus sp.) can absorb oxygen from the surrounding water directly through their skin and may obtain 10-22% in this manner. The sea kraits (Laticauda sp.), seem to be the least well-adapted to an aquatic life, having wide ventral scales, a poorly developed tail fin and needing to return to land in order to mate and lay eggs (oviparous).

All elapids have a pair of proteroglyphous (hollow) fangs that are used to inject venom from glands located towards the rear of the upper jaws. Each of the two fangs is located at the front of the mouth on a largely immovable and short maxillary bone. When the mouth is closed, the fangs fit into grooved slots in the buccal floor. Due to this construction, elapids must actually bite in order to envenomate. This action is therefore not as quick as with the viperids, that can envenomate with only a quick, stabbing motion. Elapids use their venom both to immobilize their prey and in self-defense.

Venom

All elapids are venomous and many are potentially deadly. The venoms are mostly neurotoxic and are considered more dangerous than the mainly proteolytic viper venoms. Members include the Black Mamba (Dendroaspis polylepis), a species many regard as the world's most dangerous snake, the Fierce Snake (Oxyuranus microlepidotus), the most venomous land snake, but not Hydrophis belcheri, a sea snake and the most venomous snake of all, which is a member of the Hydrophiidae.

Taxonomy

The table below lists all of the elapid genera and no subfamilies. In the past, many subfamilies were recognized, or have been suggested for the Elapidae, including the Elapinae, Hydrophiinae (sea snakes), Micrurinae (coral snakes), Acanthophiinae (Australian elapids) and the Laticaudinae (sea kraits). Currently, none are universally recognized. It seems certain that the elapids will be broken up eventually, but there are still a number of unresolved issues as to how this should be done. One involves the former Hydrophiidae, a group for which Rasmussen (2002) provided evidence suggesting that its members are phylogenetically more related to other elapids than they are to each other.

The type genus for the Elapidae was originally Elaps, but that group was moved to another family. In contrast to what usually happens in botany, the Elapidae family was not renamed. In the meantime, Elaps was renamed Homoroselaps and moved back to the Elapidae. However, Nagy et al. 2005 regard it as a sister taxon to Atractaspis which should therefore have been assigned to the Atractaspididae.

Genera

Genus Authority Species Subsp.* Common name Geographic range
Acalyptophis Boulenger 1 0 Spiny-headed seasnake Gulf of Thailand, South China sea, coast of Guangdong and Strait of Taiwan, Indonesia, Philippines, New Guinea, New Caledonia, Australia (Northern Territory, Queensland, Western Australia)
Acanthophis Daudin, 9 2 Death adders Australia, New Guinea, Indonesia (Seram, Tanimbar)
Aipysurus Lacépède, 8 0   Timor Sea, South China Sea, Gulf of Thailand, coast of Australia (North Territory, Queensland, West Australia), New Caledonia, Loyalty Islands, southern New Guinea, Indonesia, western Malaysia, Vietnam
Aspidelaps Fitzinger, 2 5 Shieldnose cobras South Africa (Cape Province, Transvaal), Namibia, southern Angola, Botswana, Zimbabwe,Mozambique
Aspidomorphus Fitzinger 3 3 Collared adders New Guinea
Astrotia Fischer 1 0 Stoke's sea snake Coastal areas from west India and Sri Lanka through Gulf of Thailand to China Sea, west Malaysia, Indonesia east to New Guinea, north and east coasts of Australia, Philippines
Austrelaps Worrell 3 0 Australian Copperheads Australia (South Australia, New South Wales, Victoria, Tasmania)
Boulengerina Dollo 2 1 Water cobras Cameroon, Gabon, Democratic Republic of the Congo, Congo, Central African Republic, Tanzania, Equatorial Guinea, Rwanda, Burundi, Zambia
Bungarus Daudin 12 5 Indian kraits India (incl. Andaman Island), Myanmar, Nepal, Vietnam, Afghanistan, Pakistan, Sri Lanka, Bangladesh, Cambodia, Indonesia (Java, Sumatra, Bali, Sulawesi), Peninsular Malaysia, Singapore, Thailand
Cacophis Günther 4 0 Dwarf crowned snakes Australia (New South Wales, Queensland)
Calliophis Gray 11 18 Oriental coral snakes India, Bangladesh, Sri Lanka, Nepal, Indonesia, Cambodia, Malaysia, Singapore, Thailand, Burma, Brunei, Philippines, Vietnam, Laos, southern China, Japan (Ryukyu Islands), Taiwan
Demansia Gray 8 3 Venomous whip snakes New Guinea, continental Australia
Dendroaspis Schlegel 4 2 Mambas Kenya, Tanzania, Mozambique, Malawi, Zimbabwe, South Africa, Ghana, Togo, Benin, Nigeria, Cameroon, Guinea, Gabon, Principe (Gulf of Guinea), Central African Republic, Democratic Republic of the Congo, Congo, Uganda, Rwanda, Burundi, Equatorial Guinea, Angola, Sudan, Botswana, Burkina Faso, Eritrea, Senegal, Mali, Ethiopia, Ivory Coast, Namibia, Somalia, Swaziland, Zambia, Gambia, Guinea Bissau, Liberia, Ivory Coast, Sierra Leone
Denisonia Krefft, 1869 2 0 Ornamental snakes Central Queensland and central northern New South Wales, Australia
Disteira Worrell, 1961 4 0    
Drysdalia Worrell, 1961 3 0 Australian crowned snakes Australia
Echiopsis Fitzinger, 1843 2 0 Bardick snakes Australia
Elapognathus Boulenger, 1896 2 0 Little brown snakes Australia
Elapsoidea Bocage, 1866 9 7 Venomous garter snakes Senegal, South Africa, Mozambique, Namibia, Botswana, Zimbabwe, Swaziland, Gambia, Angola, Benin, Burkina Faso, Cameroon, Central African Republic, Chad, Ghana, Ivory Coast, Malawi, Mali, Mauritania, Niger, Nigeria, Uganda, Senegal, Sudan, Tanzania, Togo, Democratic Republic of the Congo, Congo, Zambia, Kenya, north Burundi, Rwanda, Ethiopia, Uganda, Somalia
Emydocephalus Krefft, 1869 2 0 Turtlehead sea snakes  
Enhydrina Gray, 1849 2 0 Beaked sea snakes  
Ephalophis M.A. Smith, 1931 1 0 Grey's sea snake  
Furina Duméril, 1853 5 0 Naped snakes  
Hemachatus Fleming, 1822 1 0 Spitting cobra South Africa, Zimbabwe, Lesotho, Swaziland
Hemiaspis Fitzinger, 1861 2 0 Swamp snakes  
Hemibungarus Peters, 1862 3 2 Asian coral snakes Taiwan, Japan (Ryukyu Islands)
Homoroselaps Jan, 1858 2 0 Harlequin snakes  
Hoplocephalus Wagler, 1830 3 0 Pale-headed snakes Eastern Australia
Hydrelaps Boulenger, 1896 1 0 Port Darwin seasnake  
Hydrophis Latreille, 1801 29 5 Asian sea snakes  
Kerilia Gray, 1849 1 1 Jerdon's sea snake  
Kolpophis M.A. Smith, 1926 1 0 Bighead sea snake  
Lapemis Gray, 1835 2 0 Shaw's sea snake  
Laticauda Laurenti, 1768 7 2 Sea kraits  
Leptomicrurus Schmidt, 1937 4 2 Blackback Coral Snake  
Loveridgelaps McDowell, 1970 1 0 Solomon's small-eyed snake  
Micropechis Boulenger, 1896 1 0 New Guinea small-eyed snake  
Micruroides Schmidt, 1928 1 2 Western coral snakes USA (Arizona, SW New Mexico), Mexico (Sonora, Sinaloa)
Micrurus Wagler, 1824 68 64 Coral snakes  
Naja Laurenti, 1768 21 5 Cobras  
Notechis Boulenger, 1896 2 4 Tiger snakes Southern Australia, including many offshore islands
Ogmodon Peters, 1864 1 0 Fiji cobra  
Ophiophagus Günther, 1864 1 0 King cobra Bangladesh, Myanmar, Cambodia, China, India, Andaman Islands, Indonesia, Laos, Thailand, Vietnam, west Malaysia, Philippines
Oxyuranus Kinghorn, 1923 2 1 Taipans Australia, New Guinea
Parahydrophis Burger & Natsuno, 1974 1 0 Northern mangrove sea snake  
Paranaja Loveridge, 1944 1 2 Many-banded snakes West/central Democratic Republic of the Congo, Congo, Cameroon
Parapistocalamus Roux, 1934 1 0 Hediger's snake  
Pelamis Daudin, 1803 1 0 Yellow-bellied sea snake  
Pseudechis Wagler, 1830 7 2 Black snakes (and king brown) Australia
Pseudohaje Günther, 1858 2 0 Forest cobras Angola, Burundi, Cameroon, Central African Republic, Democratic Republic of the Congo, Congo, Gabon, Ghana, Kenya, Nigeria, Rwanda, Uganda, Sierra Leone, Liberia, Ivory Coast, Togo, Nigeria
Pseudonaja Günther, 1858 8 3 Venomous brown snakes (and dugites) Australia
Rhinoplocephalus Müller, 1885 6 0    
Salomonelaps McDowell, 1970 1 0 Solomons coral snake  
Simoselaps Jan, 1859 14 3 Australian coral snakes  
Suta Worrell, 1961 10 2 Curl snake Australia
Thalassophina P. Schmidt, 1852 1 0 Schmidt's sea snake  
Thalassophis P. Schmidt, 1852 1 0 Anomalous sea snake  
Toxicocalamus Boulenger, 189 9 1 Forest snakes  
Tropidechis Günther, 1863 1 0 Rough-scaled snake Eastern Australia
Vermicella Gray, 1858 5 0 Bandy-bandies  
Walterinnesia Lataste, 1887 1 0 Black desert cobra Egypt, Israel, Lebanon, Syria, Jordan, Iraq, Iran, Kuwait, Saudi Arabia

*) Not including the nominate subspecies (typical form).

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