The Viperidae (vipers) are a family of venomous snakes found in most parts of the world, excluding Antarctica, Australia, New Zealand,Madagascar, Hawaii, various other isolated islands, and north of the Arctic Circle. All have relatively long, hinged fangs that permit deep penetration and injection of venom. Four subfamilies are currently recognised. They are also known as viperids. The name "viper" is derived from the Latin word, vipera, -ae, which means "viper".
Mexican west coast rattlesnake
All viperids have a pair of relatively long solenoglyphous (hollow) fangs that are used to inject venom from glands located towards the rear of the upper jaws, just behind the eyes. Each of the two fangs is at the front of the mouth on a short maxillary bone that can rotate back and forth. When not in use, the fangs fold back against the roof of the mouth and are enclosed in a membranous sheath. The left and right fangs can be rotated together or independently. During a strike, the mouth can open nearly 180° and the maxilla rotates forward, erecting the fangs as late as possible so that the fangs do not become damaged, as they are brittle. The jaws close upon impact and the muscular sheaths encapsulating the venom glands contract, injecting the venom as the fangs penetrate the target. This action is very fast; in defensive strikes, it will be more a stab than a bite. Viperids use this mechanism primarily for immobilization and digestion of prey. Secondarily, it is used for self-defence, though in cases with nonprey, such as humans, they may give a dry bite (not inject any venom). A dry bite allows the snake to conserve their precious reserve of venom, because once it has been depleted, it takes time to replenish, leaving the snake vulnerable.
Almost all vipers have keeled scales, a stocky build with a short tail, and due to the location of the venom glands, a triangle-shaped head distinct from the neck. The great majority have vertically elliptical, or slit-shaped, pupils that can open wide to cover most of the eye or close almost completely, which helps them to see in a wide range of light levels. Typically, vipers are nocturnal and ambush their prey.
Compared to many other snakes, vipers often appear rather sluggish. Most are ovoviviparous, giving birth to live young, but a few lay eggs.
Viperid snakes are found in the Americas, Africa, and Eurasia. In the Americas, they are native from southern Canada, through theUnited States, Mexico, Central America, and into South America. The adder branch of the Viperidae family contains the only venomous snake found in Great Britain. Wild viperids are not found in Australia.
A rattlesnake skull, showing the long fangs used to inject venom
Viperid venoms typically contain an abundance of protein-degrading enzymes, called proteases, that produce symptoms such as pain, strong local swelling and necrosis, blood loss from cardiovascular damage complicated by coagulopathy, and disruption of the blood-clotting system. Death is usually caused by collapse in blood pressure. This is in contrast to elapid venoms that generally contain neurotoxins that disable muscle contraction and cause paralysis. Death from elapid bites usually results from asphyxiation because the diaphragm can no longer contract. However, this rule does not always apply; some elapid bites include proteolytic symptoms typical of viperid bites, while some viperid bites produce neurotoxic symptoms.
Proteolytic venom is also dual-purpose: firstly, it is used for defense and to immobilize prey, as with neurotoxic venoms; secondly, many of the venom's enzymes have a digestive function, breaking down molecules in prey items, such as lipids, nucleic acids, and proteins. This is an important adaptation, as many vipers have inefficient digestive systems.
Due to the nature of proteolytic venom, a viperid bite is often a very painful experience and should always be taken seriously, though it may not necessarily prove fatal. Even with prompt and proper treatment, a bite can still result in a permanent scar, and in the worst cases, the affected limb may even have to be amputated. A victim's fate is impossible to predict, as this depends on many factors, including the species and size of the snake involved, how much venom was injected (if any), and the size and condition of the patient before being bitten. Viper bite victims may also be allergic to the venom and/or the antivenom.
These snakes are capable of making decisions on how much venom to inject depending on the circumstances. In all cases, the most important determinant of venom expenditure is generally the size of the snake, with larger specimens being capable of delivering much more venom. The species is also important, since some are likely to inject more venom than others, may have more venom available, strike more accurately, or deliver a number of bites in a short time. In predatory bites, factors that influence the amount of venom injected include the size of the prey, the species of prey, and whether the prey item is held or released. The need to label prey for chemosensory relocation after a bite and release may also play a role. In defensive bites, the amount of venom injected may be determined by the size or species of the predator (or antagonist), as well as the assessed level of threat, although larger assailants and higher threat levels may not necessarily lead to larger amounts of venom being injected.
Hemotoxic venom takes more time than neurotoxic venom to immobilize prey, so viperid snakes need to track down prey animals after they have been bitten, in a process known as "prey relocalization". Vipers are able to do this via certain proteins contained in their venom. This important adaptation allowed rattlesnakes to evolve the strike-and-release bite mechanism, which provided a huge benefit to snakes by minimizing contact with potentially dangerous prey animals. However, this adaptation then requires the snake to track down the bitten animal to eat it, in an environment full of other animals of the same species. Western diamondback rattlesnakes (Crotalus atrox) respond more actively to mouse carcases that have been injected with crude rattlesnake venom.
The western diamondback rattlesnake Crotalus atrox, the venom of which contains proteins allowing the snake to track down bitten prey
When the various components of the venom were separated out, the snakes responded to mice injected with two kinds of disintegrins. These disintegrin proteins are responsible for allowing the snakes to track down their prey.
That Viperidae family as attributed to Oppel (1811), as opposed to Laurenti (1768) or Gray (1825), is subject to some interpretation. However, the consensus among leading experts is that Laurenti used viperae as the plural of vipera (Latin for "viper", "adder", or "snake") and did not intend for it to indicate a family group taxon. Rather, it is attributed to Oppel, based on his Viperini as a distinct family group name, despite the fact that Gray was the first to use the form Viperinae.
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courtesy to : www.reptilesmagazine.com/Snake-Species/Gaboon-Viper/
Adult Size: Commonly attains 3½ to 4½ feet in length; occasionally may attain 6 feet. This snake has a proportionately immense girth.
Range: Most abundant in central and east Africa but of spotty distribution as far south as Zimbabwe and Zululand.
Habitat: Montane forests, coastal forests and scrubby coastal dunes.
Captive Lifespan: 12 to 20 Years
Care Level: Advanced
If not the most magnificent African venomous snake, it is certainly the most magnificent of the African viperine species. There are two subspecies, The East African, B. g. gabonica with small nasal horns and two dark triangles beneath each eye and the West African, B. g. rhinoceros with large nasal horns and a single triangle beneath each eye. Despite the immense size of this viper its ground and pattern colors of last autumnâs fallen leaves renders it nearly invisible on the forest floor. This is a slow moving snake that often crawls in a straight line (rectilinear movement). If startled or threatened it may coil but will as often merely freeze in place and depend on camouflage to avoid detection. This nocturnal snake is generally quiescent during the hours of daylight when it can seldom be induced to bite. It is more active and apt to bite at night. And you must keep in mind that a Gaboon can strike upwards or to the sides as well as forward.
Many of the gaboon vipers that are offered for sale are either wild collected or âfarmedâ in Africa. These should be checked for internal parasites. Sadly, many of these imports are also very badly dehydrated when received by hobbyists and it is imperative that they be induced to drinkâ”quickly and copiously. Even if the water dish is low and of broad diameter the Gaboon Viper may not recognize it for what it is. This lack of recognition can often be cured by roiling the waterâs surface with an aquarium air stone activated by a small vibrator pump. Eventually the gaboon will recognize even still waters for what they are.
A single gaboon viper can be housed in a 75 gallon capacity terrarium but larger is better; a pair should have a terrarium of at least 125 gallon capacity and again, larger is better. Although a substrate may be of folded newspaper, several thicknesses of paper towels, or aspen shavings, to truly appreciate the beauty and camouflage colors of this snake a bottom covering of cypress shavings and/or dried leaves is suggested. A hidebox may be used by a juvenile gaboon viper but adults usually merely sit quietly in the open. A receptacle of fresh, clean water must be present.
Daytime illumination should be provided. A temperature gradient should be provided these snakes. The cool end of the terrarium can be about 76 degrees Fahrenheit and the hot end about 85 degrees. A daytime hot spot of about 92 to 95 degrees should be provided by a basking lamp. Gaboon vipers are active all winter long. It does not require temperature manipulation to breed gaboon vipers. Often times breeding interests will be aroused by a passing frontal system that lowers barometric pressure. A gentle misting at this time may stimulate them further.
A litter may contain from 10 to more than 40, 9 to 14 inch long neonates.
Captive gaboon vipers thrive on suitably sized prekilled mice (baby snakes) or rats (adult snakes).
Small gaboons may be moved with a snakehook; large individual are so heavy that to move them safely you will need 2 snakehooks, one fore and one aft.
Most specimens are wild-caught and should be thoroughly vetted for intestinal and other parasites, neck problems and paramyxovirus infection (âstar-gazing diseaseâ). They also may be severely dehydrated and need to be soaked as they adapt to the terrarium. The terrarium should be at least equal to the length of the snake, so plan for roughly 4 feet square for an adult. It should be about 3 feet high, with a basking light placed toward the top of the terrarium. For a substrate use 2 inches of sphagnum moss, orchid bark or any other material that can hold a high moisture content. The terrarium should be waterproofed. Provide a large, shallow water bowl in which the snake can soak; change the water regularly. The temperature should be kept low, just 70 to 78 degrees Fahrenheit. Persistent temperatures over 80 degrees can lead to dehydration and death. A lockable hide box is essential.
Rhinoceros vipers spend much of the day partially hidden in the substrate and are most active at night. They take a variety of prey, ranging from hopper mice for young specimens to rats for large adults. Difficult feeders may take gerbils when other rodents are refused. In the wild, frogs and fish also are eaten.
The venom of the rhinoceros viper is considered to be relatively weak and is more likely to cause severe tissue damage than death, but certainly a bite is not pleasant. Antivenin for gaboon vipers works for this species as well.
Adult Size: 2½ to 3 feet long, with a very stout body
Range: Found widely across central tropical Africa from Guinea and Liberia on the western coast through the Congo to Kenya.
Habitat: Rhinoceros vipers are a species of deep rain forests and often are associated with forest pools and low areas that flood regularly. It is a very sedentary ambush predator but a climbs surprisingly well.
Captive Lifespan: 8 to 12 Years
Care Level: Advanced
courtesy to : www.reptilesmagazine.com/Snake-Species/Rhinoceros-Viper/
Other and recommended websites :
Gaboon Care Information
courtesy to : www.gaboonviper.org/gaboon-care-information/
Hids and Decorations
When keeping any venomous snake I suggest keeping the decorations in the cage to a minimum. I
like to see where the sharp end of the snake is at all times. Gaboons do not need a hide spot if they are being kept on a natural substrate because they get enough security just by shuffling their way under the mulch or whatever natural bedding you use. If you opt to use paper towels you should offer some sort of hide spot.
There are a lot of FALSE statements flying around the internet and other sourses, about the “tameness” and “placidness” of the gaboon viper. They are by NO means tame. A gaboon viper can
lure you into thinking they are tame because of their “laziness”. As mentioned before the are an ambush predator and that is the nature of the beast. They will bite if you put yourself within its strike range. Gaboons are some of the hardest, fastest striking snakes in the world and they can do it from any position they are laying in. Their agility is unbelievable. Their strike can be almost acrobatic.Their accuracy is scary. In all of my years of keeping venomous snakes I have never seen one miss its intended target.
No venomous snake should ever be handled without the proper tools. Hooks are a must when handling the gaboon viper. A large animal up to 2 feet will ride a single hook without much fuss. Adults should be handled with two hooks to avoid breaking ribs and huge adults should be handled with hooks that have a wide surface area like the MidWest custom python hook. Inexperienced handlers should never attempt to tail a gaboon. They can strike back over their bodies. Another tool that aids in the handling these guys especially when giving meds and force feeding are clear tubes. They are perfect for when a situation calls for a more hands on approach.. Trap boxes are also suggested.
Bitis Gabonica Venom
Gaboon venom contains:
Anticoagulants (not specified)
Heamorrhagins (zinc metalloproteinase)
Cardiotoxins (not specified)
Necrotoxins (not specified)
Neurotoxins (not specified)
Cytotoxins (not specified)
Gaboon vipers can deliver severe envenomations and have a high lethality potential. Rate of envenomation is between 60% to 80%. Untreated lethality rate is unknown but most likely very high.
Local effects include pain, severe swelling, bruising, blistering and bleeding. Local necrosis can be moderate to severe. General effects include headache, nausea, vomiting, abdominal pain, diarrhea, dizziness, collapsing, and convulsions.
A bite also causes minor neurotoxic paralysis.
Coagulopathy and hemorrhages are very common causing internal bleeding which is one of the major clinical effects. Cardio toxicity is also a major clinical effect. Shock secondary to fluid shifts due to local tissue damage is likely in severe cases.
Info on the venom content was taken from the WHC Clinical Toxicology Resources.
An LD50 of 12.5 and a venom yield of up to 600mg makes this a very serious species as far as a bite goes. Lucky for us they are not very aggressive and when handled correctly bites are not too common. Antivenin should be kept on site when maintaining exotic venomous species. AV used for gaboon bites is called SAIMR polyvent. From experience I know that gaboon vipers have an immunity to their own venom. One of my females bit a male during feeding. There was clear signs of an envenomation at first. The male suffered nothing more than a swollen head and this subsided after a few days and some cleaning up of the wounds.
The gaboon viper is not a snake to be kept by the beginner or inexperienced venomous snake keeper. They can be extremely dangerous in the wrong hands and should only be left to the experience hot keepers.
All of this info can be used to keep the East African gaboon viper (Bitis gabonica gabonica). Their captive requirements are exactly the same and East African gaboon vipers will thrive under these same guide lines.
Please not that this care sheet is in no way condoning the keeping of the gaboon viper or any venomous snake. The info was simply posted for those experienced enough to competently and safely maintain the gaboon viper in a captive situation.
West African Gaboon Vipers
Handling Bitis gabonica (Gaboon Viper)
west african gaboon viper bite.!
west african gaboon viper( Bitis rhinoceros)
Working with Rhino Vipers
Rhino Viper care "sheet"
African Gaboon Vipers
Working with Rhino Vipers
Rhinoceros Viper (Bitis nasicornis)
Caleb feeding rhino viper
Rhino Viper (Bitis nasicornis) venom extraction at KRZ.
Further Reading :
by Linda George (Author)
by R.D. Bartlett (Author), Kenneth Wray (Author)
by Dick Visser (Author)
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