Hottentotta tamulus
Encyclopedia
Hottentotta tamulus, the Indian red scorpion (also known as eastern Indian scorpion), is a species of scorpion, belonging to the family Buthidae
. It occurs in most of India
, eastern Pakistan
and the eastern lowlands of Nepal
.
in 1798. The species name was apparently derived from the occurrence in the country of the Tamil people
of south-eastern India. It was later often referred to the genera
Buthus or Mesobuthus, although it was already correctly placed in Hottentotta by A. A. Birula in 1914, a referral that was confirmed again by F. Kovařík in 2007. Nevertheless, the binomen
Mesobuthus tamulus is traditionally widespread in the popular and scientific literature.
R.I. Pocock
(1900) distinguished five subspecies
according to coloration and distribution, but these are color-morphs (individuals with varying color) rather than subspecies.
and the mesosoma
. The walking legs and the tip of the pedipalp pincers are brighter colored (orange-yellow to light reddish-brown). The mesosoma
l tergites always bear three distinct carinae. Their habitus
is typical of buthid
scorpions, with rather small pedipalp
pincers, moderately thickened metasoma
l segments and a rather bulbous telson
with large stinger. The base of the pedipalp pincers (manus) is slightly more inflated in males than in females.
Symptoms of envenomation by this species include:
The venom mainly affects the cardiovascular and pulmonary system, eventually leading to a pulmonary oedema, which may cause death. Scorpion antivenom has little effect in clinical treatment but application of prazosin
reduces the mortality rate to less than 4%.
As in other scorpions, the venom of H. tamulus consists of a complex mixture of protein
s. Some major components have been isolated, including the toxin
tamapin
.
and habitat
preferences of this species. It is widespread across vegetated lowlands with subtropical to tropical, humid climate and often lives close to or in human settlements, especially in rural areas. As all other scorpions, H. tamulus is nocturnal, preying upon small invertebrates and even small vertebrates like lizard
s. Encounters with humans mainly occur during the night or early morning, when the scorpions accidentally crawl into beds or fall from ceilings.
Buthidae
Buthidae is the largest family of scorpions, containing about 80 genera and over 800 species as of mid-2008. Its members are known as, for example, thick-tailed scorpions and bark scorpions. There are a few very large genera , but also a high number of species-poor or monotypic ones...
. It occurs in most of India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
, eastern Pakistan
Pakistan
Pakistan , officially the Islamic Republic of Pakistan is a sovereign state in South Asia. It has a coastline along the Arabian Sea and the Gulf of Oman in the south and is bordered by Afghanistan and Iran in the west, India in the east and China in the far northeast. In the north, Tajikistan...
and the eastern lowlands of Nepal
Nepal
Nepal , officially the Federal Democratic Republic of Nepal, is a landlocked sovereign state located in South Asia. It is located in the Himalayas and bordered to the north by the People's Republic of China, and to the south, east, and west by the Republic of India...
.
Taxonomy
This species was named Scorpio tamulus by J.C. FabriciusJohan Christian Fabricius
Johan Christian Fabricius was a Danish zoologist, specialising in "Insecta", which at that time included all arthropods: insects, arachnids, crustaceans and others...
in 1798. The species name was apparently derived from the occurrence in the country of the Tamil people
Tamil people
Tamil people , also called Tamils or Tamilians, are an ethnic group native to Tamil Nadu, India and the north-eastern region of Sri Lanka. Historic and post 15th century emigrant communities are also found across the world, notably Malaysia, Singapore, Mauritius, South Africa, Australia, Canada,...
of south-eastern India. It was later often referred to the genera
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Buthus or Mesobuthus, although it was already correctly placed in Hottentotta by A. A. Birula in 1914, a referral that was confirmed again by F. Kovařík in 2007. Nevertheless, the binomen
Binomen
In zoological nomenclature, a binomen , is the two-part name of a species. The term was introduced in 1953, abolishing the previously used "binomial name" . A binomen consists of a generic name and a specific epithet...
Mesobuthus tamulus is traditionally widespread in the popular and scientific literature.
R.I. Pocock
Reginald Innes Pocock
Reginald Innes Pocock F.R.S. was a British zoologist.Pocock was born in Clifton, Bristol, the fourth son of Rev. Nicholas Pocock and Edith Prichard. He began showing interest in natural history at St. Edward's School, Oxford. He received tutoring in zoology from Sir Edward Poulton, and was allowed...
(1900) distinguished five subspecies
Subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
according to coloration and distribution, but these are color-morphs (individuals with varying color) rather than subspecies.
Description
H. tamulus specimen range in size from 50–90 mm. The coloration ranges from dark orange or brightly red-brown through dull brown with darker grey carinae (ridges) and granulation. Grey spots might be distributed irregularly across the cephalothoraxCephalothorax
The cephalothorax is a tagma of various arthropods, comprising the head and the thorax fused together, as distinct from the abdomen behind. The word cephalothorax is derived from the Greek words for head and thorax...
and the mesosoma
Mesosoma
The mesosoma is the middle part of the body, or tagma, of arthropods whose body is composed of three parts, the other two being the prosoma and the metasoma. It bears the legs, and, in the case of winged insects, the wings....
. The walking legs and the tip of the pedipalp pincers are brighter colored (orange-yellow to light reddish-brown). The mesosoma
Mesosoma
The mesosoma is the middle part of the body, or tagma, of arthropods whose body is composed of three parts, the other two being the prosoma and the metasoma. It bears the legs, and, in the case of winged insects, the wings....
l tergites always bear three distinct carinae. Their habitus
Morphology (biology)
In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....
is typical of buthid
Buthidae
Buthidae is the largest family of scorpions, containing about 80 genera and over 800 species as of mid-2008. Its members are known as, for example, thick-tailed scorpions and bark scorpions. There are a few very large genera , but also a high number of species-poor or monotypic ones...
scorpions, with rather small pedipalp
Pedipalp
Pedipalps , are the second pair of appendages of the prosoma in the subphylum Chelicerata. They are traditionally thought to be homologous with mandibles in Crustacea and insects, although more recent studies Pedipalps (commonly shortened to palps or palpi), are the second pair of appendages of the...
pincers, moderately thickened metasoma
Metasoma
The metasoma is the posterior part of the body, or tagma, of arthropods whose body is composed of three parts, the other two being the prosoma and the mesosoma. In insects, it contains most of the digestive tract, respiratory system, and circulatory system, and the apical segments are typically...
l segments and a rather bulbous telson
Telson
The telson is the last division of the body of a crustacean. It is not considered a true segment because it does not arise in the embryo from teloblast areas as do real segments. It never carries any appendages, but a forked "tail" called the caudal furca is often present. Together with the...
with large stinger. The base of the pedipalp pincers (manus) is slightly more inflated in males than in females.
Toxicity
This species is of great medical significance in densely populated areas of India and Nepal and occasionally causes human fatalities. It is rated the most lethal scorpion species in the world. Fatality rates of 8-40% have been reported in clinical studies, most victims are children.Symptoms of envenomation by this species include:
- Severe local pain
- VomitingVomitingVomiting is the forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose...
- Sweating
- PriapismPriapismPriapism is a potentially harmful and painful medical condition in which the erect penis or clitoris does not return to its flaccid state, despite the absence of both physical and psychological stimulation, within four hours. There are two types of priapism: low-flow and high-flow. Low-flow...
- CyanosisCyanosisCyanosis is the appearance of a blue or purple coloration of the skin or mucous membranes due to the tissues near the skin surface being low on oxygen. The onset of cyanosis is 2.5 g/dL of deoxyhemoglobin. The bluish color is more readily apparent in those with high hemoglobin counts than it is...
- UnconsciousnessUnconsciousnessUnconsciousness is the condition of being not conscious—in a mental state that involves complete or near-complete lack of responsiveness to people and other environmental stimuli. Being in a comatose state or coma is a type of unconsciousness. Fainting due to a drop in blood pressure and a...
- Muscular convulsions
- Breathlessness
- Pink frothy sputumSputumSputum is mucus that is coughed up from the lower airways. It is usually used for microbiological investigations of respiratory infections....
- Cardiac dysrhythmiaDysrhythmiaDysrhythmia is an American instrumental progressive metal band formed in Philadelphia, Pennsylvania in 1998. The band's music combines avant-garde elements of progressive rock and jazz with heavy metal...
- TachycardiaTachycardiaTachycardia comes from the Greek words tachys and kardia . Tachycardia typically refers to a heart rate that exceeds the normal range for a resting heart rate...
or bradycardiaBradycardiaBradycardia , in the context of adult medicine, is the resting heart rate of under 60 beats per minute, though it is seldom symptomatic until the rate drops below 50 beat/min. It may cause cardiac arrest in some patients, because those with bradycardia may not be pumping enough oxygen to their heart... - HypotensionHypotensionIn physiology and medicine, hypotension is abnormally low blood pressure, especially in the arteries of the systemic circulation. It is best understood as a physiologic state, rather than a disease. It is often associated with shock, though not necessarily indicative of it. Hypotension is the...
or hypertensionHypertensionHypertension or high blood pressure is a cardiac chronic medical condition in which the systemic arterial blood pressure is elevated. What that means is that the heart is having to work harder than it should to pump the blood around the body. Blood pressure involves two measurements, systolic and... - Acute myocarditisMyocarditisMyocarditis is inflammation of heart muscle . It resembles a heart attack but coronary arteries are not blocked.Myocarditis is most often due to infection by common viruses, such as parvovirus B19, less commonly non-viral pathogens such as Borrelia burgdorferi or Trypanosoma cruzi, or as a...
- Shock
The venom mainly affects the cardiovascular and pulmonary system, eventually leading to a pulmonary oedema, which may cause death. Scorpion antivenom has little effect in clinical treatment but application of prazosin
Prazosin
Prazosin, trade names Minipress, Vasoflex, Pressin and Hypovase, is a sympatholytic drug used to treat high blood pressure and Anxiety, PTSD and Panic Disorder. It belongs to the class of alpha-adrenergic blockers. Specifically, prazosin is selective for the alpha-1 receptors on vascular smooth...
reduces the mortality rate to less than 4%.
As in other scorpions, the venom of H. tamulus consists of a complex mixture of protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
s. Some major components have been isolated, including the toxin
Toxin
A toxin is a poisonous substance produced within living cells or organisms; man-made substances created by artificial processes are thus excluded...
tamapin
Tamapin
Tamapin is a toxin from the Indian Red Scorpion , which is a selective and potent blocker of SK2 channels.- Chemical structure & methods of isolation :...
.
Habitat and ecology
Despite its medical importance, few is known about the ecologyEcology
Ecology is the scientific study of the relations that living organisms have with respect to each other and their natural environment. Variables of interest to ecologists include the composition, distribution, amount , number, and changing states of organisms within and among ecosystems...
and habitat
Habitat
* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...
preferences of this species. It is widespread across vegetated lowlands with subtropical to tropical, humid climate and often lives close to or in human settlements, especially in rural areas. As all other scorpions, H. tamulus is nocturnal, preying upon small invertebrates and even small vertebrates like lizard
Lizard
Lizards are a widespread group of squamate reptiles, with nearly 3800 species, ranging across all continents except Antarctica as well as most oceanic island chains...
s. Encounters with humans mainly occur during the night or early morning, when the scorpions accidentally crawl into beds or fall from ceilings.
External links
- Images of various Hottentotta species, including H. tamulus: Exotics.nl.