Adder

Adders are in the groups of venomous snakes. Adders belong to the viper family Viperidae. The Australo-Papuan death adders are viper snake belongs to the cobra family Elapidae. As per the research, the name adder may be given to many snakes of various families. For example, the Heterodon is also known as hognose snakes are the harmless North American genus.  The adder snakes under the viper family are the European common adder, Puff adders and the Night adders. 

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Adder meaning venomous snake. The above image shows a type of adder, which has a slender body located near the field.

Types of Adders and Their Characteristics 

Adder meaning venomous snake. Huge varieties of adders are present in the world. Adders are kept in different families.  The scientific name of the European common adder or European viper is V.berus. These snakes are often mentioned in literature work. European common adders are one of the stout-bodied snakes, which is spread over in Europe and Asia. Can also encounter in the north of the Arctic circle in Norway. The European vipers can grow up to the maximum length of about 85 cm and they are usually in grey to brown with the dark zigzag band on the back and spots on the sides. The common milk adders include frogs, young birds and small mammals in their diet. These species rarely bite human beings. 

The scientific name of the puff adder is B. arietans. The puff adders are the large venomous snakes that are widely found in the semiarid regions of Africa and Arabia. They usually arise warning by inflating their body and creating loud hissing. The puff adders can grow up to the length of about 1 to 1.5 meters and are in grey to dark brown in colour with thin yellow chevrons on their back. The puff adders are the thick-bodied snake with a potentially lethal bite. So, while approaching the puff adders they can stay put, rather than flee. 

Causus are the night adders, which are small venomous vipers that are found only in the sub - Saharan African region. They can grow up to a maximum length of about 1 metre. The night adders are active at night and feed nearly exclusively on frogs and toads.

Acanthophis are the death adders, that are related to the slender-bodied cobras. Usually, the death adders are in viper like appearance with thick bodies, short tails and broadheads. The death adders can reach a maximum length of about 45 to 90cm. Usually, death adders are grey or brownish in colour with darker crosswise bands on their bodies. Habitat of death adders is spread over in the desert to the rainforest in Australia and New Guinea.   A. antarcticus is mostly found in the more temperate regions and maritime eastern and southern coasts of Australia.  The taxonomy of the death adders are still uncertain and death adders from New Guinea have been kept under three species A. praelongus, A. laevis, and A. rugosus. 

A. pyrrhus is the desert death adder that is found only in arid areas of Australia.

Usually, the death adders are sedentary predators and their major prey are frogs, lizards and small mammals. Death adders can give birth to 10 - 30 young snakes at the end of every gestation period. The death adders are the dangerous snakes, which can produce a potent venom, that can cause the death of one-half of untreated cases.

De Vis' banded snake is also known as sand adders. The sand adders are the endemic species, that are found in certain regions of eastern Australia. They are much suitable for both dry and wet habitats. Mud adders are sluggish snakes inhabiting low-lying areas. They prefer to stay in the soil cracks or deep cavities and are active during nights to catch frogs for feed. At the end of each gestation period, the snakes will produce five to 11 species. Usually, the sand adders are of two types, they are Dwarf sand adder and Namib dwarf sand adder. 

The scientific name of the Eastern milk adder is  Lampropeltis triangulum triangulum. The milk adders are the nonvenomous snakes located in eastern and central North America. The eastern milk adders have slender bodies with an average length of about 60 to 91 cm. They have smooth shiny snakes.  The milk adders have heavy red or reddish-brown blotches over a grey base along the dorsal surface of the body and a black-on-white checkerboard pattern on the belly. They can lay about 6 to 24 eggs at the end of each gestation period. 

The scientific name of horned adders is Bitis caudalis. The horned adders are the venomous viper snakes, that can encounter from the region of southwest Africa. They have a unique structure like a single, large horn-like scale over each eye. The horn adders can encounter from the desert and semiarid scrubs. The average length of horn adders is about 30 to 40 cm. 

Venom of Adders 

Because of the rapid growth of the human population and maximum invasion of land decreases the range of species and bites became relatively common. Domestic animals and livestock became frequent victims of the adders. In Great Britain, the adder’s invasion of domestic animals and human beings are most common during the month of March to October. According to the study, people in Sweden are experiencing an average of thousand three hundred biting cases per year, in that about 12% of the cases require hospitalisation. About eight different antivenoms are available in the market to treat patients who have been victims of adders. In Norway, about 200 to 500 causes are reported with the bites of snakes in a year and on average one death from the snakes are registered for every ten years.  Occasionally the bites of adders became life-threatening to the small children and even adults are facing many discomforts in their life. 

In 2003, Mallow et al described the venom toxicity of adders and found that the toxicity of adders is relatively low while comparing to the other viper. In 1974, cite Minton reported the  LD50 value for mice should be 0.55 mg/kg IV,  0.80 mg/kg IP and 6.45 mg/kg SC. Later he tested the minimum lethal dose of venom for a guinea pig was 40–67 mg. While using the Daboia russelii venom on guinea pigs, it required only  1.7mg. In 1973, Brown found and provided the higher subcutaneous LD50 range between 1.0 to 4.0 mg/kg. Researchers found various experiments and found medicine to get relief from adder's venom. The length of recovery time may vary, sometimes it may take up to a year.  

Local symptoms usually experienced by people, on being a victim of adders are intense pain, followed by swelling and a tingling sensation after a few minutes to 30 minutes. The blood present in the blisters is not common. Within a few hours, the pain may spread throughout the body and may create tenderness and inflammation of the body. Later,  Reddish lymphangitic lines and bruising may appear on the skin and this may cause the whole limb to become swollen and bruised within 24 hours. For adults, the swelling may spread to the trunk and sometimes it will spread to the entire body for the children. In the rare case, the bites of adders may cause necrosis and intracompartmental syndromes 

Systemic symptoms caused by bites of adders may result in anaphylaxis and can be dramatic. The systemic symptoms usually occur after the bite of adders may cause even after an hour. Symptoms for these diseases are nausea, vomiting and retching, abdominal colic and diarrhoea, incontinence of urine and faeces, sweating, fever, vasoconstriction, tachycardia, lightheadedness, loss of consciousness, blindness, shock, angioedema of the face, lips, gums, tongue, throat and epiglottis, urticaria and bronchospasm. If these symptoms are left untreated, then they may persist or fluctuate for up to 48 hours. In some cases, they may cause cardiovascular failure. Death adders are highly toxic adders, which can inject an average of 40 to 100mg of venoms in a single bite. The average reported  LD50 of venom was about 0.4–0.5 mg/kg subcutaneous. They are completely neurotoxic and neither have hemotoxins nor mycotoxins like other venomous snakes venom. 

Sometimes, the bites of death adders may also cause paralysis in the first step and later it may lead to a complete shutdown of the respiratory system within six hours. Symptoms occurring immediately after injecting the venom by death adders can be controlled by using antivenom of death adder. Anticholinesterases are also preferable to use during envenomation, which breaks the synaptic blockade by making acetylcholine more available to the parasympathetic nervous system, thus reduces the effects of the venom.

Before introducing antivenom, about 50% of the population, who became victims of death adders died. Availability of antivenom for the bite of death adder reduced the envenomation symptoms and saved the lives of many people. 

Hibernation in Adders

Like other animals, adders prefer to go for hibernation. Most of the Adders will hibernate from October to march. During the hibernation period, they congregate in areas known as hibernacula. They act as a frost-free refuge until the spring. Some species which are undergoing hibernation for the long term causes adverse damage. 

Usually, the male adder snakes emerge from hibernation first. Usually, the male snakes are required to bask in the sunlight to be a successful breed for the whole year. They will spend nearly two months relaxing in sunlight in order to maintain their body metabolism. So that they can produce sperm even after the winter slumber.  Later the female adders will emerge in late April to May and continue their reproduction agenda with the active male adders. During the breeding season, the adders entwining themselves around one another and start dancing. But the dancing is not the part of courtship, the male and female wrestling for territorial disputes. The stronger one wins the weaker ones and the victor of the duel will mate with the female and may spend a couple of days with her.

Conservation of Adders

The count of puff adders is comparatively high in this world. Still, the exact count of the puff adders are not been evaluated by the IUCN Red List or the Convention of International Trade in Endangered Species (CITES). 

The black or European adders are kept as the threatened species in the International Union for Conservation of Nature's Red List.  United kingdom is playing important role in protecting the species count by the Scottish Wildlife Trust. 

According to the IUCN’s Red List, the death adders are kept in the stable list. According to the Queensland Department of Environment and Heritage Protection study, common death adder species are named as vulnerable species. And other species are facing a great decline in their numbers because of the development of habitats of human beings. Still, the detailed information about many adders is not present in the IUCN list.