genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...
of large
scorpions
Scorpions are predatory arachnids of the order Scorpiones. They have eight legs, and are easily recognized by a pair of grasping pincers and a narrow, segmented tail, often carried in a characteristic forward curve over the back and always end ...
belonging to the family
Scorpionidae
The Scorpionidae (burrowing scorpions or pale-legged scorpions) make up the superfamily Scorpionoidea. The family was established by Pierre André Latreille
Pierre André Latreille (; 29 November 1762 – 6 February 1833) was a French zool ...
tropical
The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in
the Southern Hemisphere at S. The tropics are also referred to ...
Africa
Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...
.
Taxonomy
The genus was introduced in 1876 by
Tamerlan Thorell
Tord Tamerlan Teodor Thorell (3 May 1830 – 22 December 1901) was a Swedish arachnologist.
Thorell studied spiders with Giacomo Doria at the Museo Civico di Storia Naturale de Genoa. He corresponded with other arachnologists, such as Octaviu ...
. Subsequent research subdivided the genus into five subgenera. In 2015 all five subgenera were raised to genus level.
Members of ''Pandinus'' are generally large scorpions (about 120–200 mm total length), which are dark to black colored, sometimes with paler
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 circul ...
and legs. The
pedipalp
Pedipalps (commonly shortened to palps or palpi) are the second pair of appendages of chelicerates – a group of arthropods including spiders, scorpions, horseshoe crabs, and sea spiders. The pedipalps are lateral to the chelicerae ("jaws") an ...
pincers are massive, while the metasoma is proportionally thin with a small vesicle and stinger (aculeus). They possess a stridulatory organ, composed of a rough area on the first segment (coxa) of the pedipalps and a 'scraper' made of bristles on the first segment of their first pair of walking legs. Scraping these bristles on the rough zone produces a scratching sound. Genera of the subfamily Scorpioninae are extremely similar to each other and ''Pandinus'' is especially close to the
Southeast Asia
Southeast Asia, also spelled South East Asia and South-East Asia, and also known as Southeastern Asia, South-eastern Asia or SEA, is the geographical south-eastern region of Asia, consisting of the regions that are situated south of mainlan ...
n genus ''
Heterometrus
''Heterometrus'', whose members are also known by the collective vernacular name giant forest scorpions, is a genus of scorpions belonging to the family Scorpionidae. It is distributed widely across tropical and subtropical southeastern Asia, in ...
''. They differ mainly in details of the stridulatory organ and sensory bristles (
trichobothria
Trichobothria (singular trichobothrium) are elongate setae ("hairs") present in arachnids, various orders of insects, and myriapods that function in the detection of airborne vibrations and currents, and electrical charge. In 1883, Friedrich Dahl ...
).
Toxicity
As in other Scorpionidae, the venom of ''Pandinus'' species is rather mild, and human fatalities are unknown. Symptoms are mostly restricted to local pain, described similar to those of a bee sting. At least ''P. imperator'' rarely stings at all, and often prefers to use its massive pincers for prey capture and even for defense. The defensive behavior of the other species is not yet studied in detail.
tropical
The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in
the Southern Hemisphere at S. The tropics are also referred to ...
low-land regions. They occur in
rain forest
Rainforests are characterized by a closed and continuous tree canopy, moisture-dependent vegetation, the presence of epiphytes and lianas and the absence of wildfire. Rainforest can be classified as tropical rainforest or temperate rainforest ...
,
gallery forest
A gallery forest is one formed as a corridor along rivers or wetlands, projecting into landscapes that are otherwise only sparsely treed such as savannas, grasslands, or deserts. The gallery forest maintains a more temperate microclimate above th ...
near rivers and other woodlands aside of savannah habitats. Arabian species also occur in
semiarid
A semi-arid climate, semi-desert climate, or steppe climate is a dry climate sub-type. It is located on regions that receive precipitation below potential evapotranspiration, but not as low as a desert climate. There are different kinds of semi- ...
climates. Soft, loamy soils seem to be preferred by most species, but ecology is only well known for the forest-living ''P. imperator''.
Conservational status
Two species of ''Pandinus'' (''P. imperator'', and ''P. gambiensis'') are the only scorpions listed by the
CITES
CITES (shorter name for the Convention on International Trade in Endangered Species of Wild Fauna and Flora, also known as the Washington Convention) is a multilateral treaty to protect endangered plants and animals from the threats of interna ...
Appendix II since 1995, due to overexploitation for pet trade from the wild. CITES
export quota
Non-tariff barriers to trade (NTBs; also called non-tariff measures, NTMs) are trade barriers that restrict imports or exports of goods or services through mechanisms other than the simple imposition of tariffs.
The Southern African Development C ...
s have been issued for ''P. imperator'' by several countries in West Africa (including
Benin
Benin ( , ; french: Bénin , ff, Benen), officially the Republic of Benin (french: République du Bénin), and formerly Dahomey, is a country in West Africa. It is bordered by Togo to the west, Nigeria to the east, Burkina Faso to the nort ...
,
Togo
Togo (), officially the Togolese Republic (french: République togolaise), is a country in West Africa. It is bordered by Ghana to the west, Benin to the east and Burkina Faso to the north. It extends south to the Gulf of Guinea, where its c ...
,
Niger
)
, official_languages =
, languages_type = National languagesChad). The CITES listing has been conceptually criticized for protecting two species, of which only one (''P. imperator'') is frequently exported for international pet trade. Even in countries with effective quotas, the origin of traded specimens either from farms or from the wild is hardly traceable. Beside of overharvesting, the species are most endangered by habitat destruction due to
deforestation
Deforestation or forest clearance is the removal of a forest or stand of trees from land that is then converted to non-forest use. Deforestation can involve conversion of forest land to farms, ranches, or urban use. The most concentrated ...
. Traded specimens are sometimes labelled ''"Pandinus africanus"''. This name is an invalid synonym for ''P. imperator'' and apparently used to avoid CITES regulations for this species. However, other - unlisted - species were also traded under this name.
In captivity
The large size, its docile and gregarious behaviour, partly diurnal activity and mild venom make ''P. imperator'' the most popular pet scorpion. After listing of the species in CITES, commercial scorpion farms have been established in several West African countries.