Solifugae is an
orderIn scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...
of
ArachnidArachnids are a class of joint-legged invertebrate animals in the subphylum Chelicerata. All arachnids have eight legs, although in some species the front pair may convert to a sensory function. The term is derived from the Greek word , meaning "spider".Most arachnids are terrestrial...
a, containing more than 1,000 described
speciesIn biology, a species is:* a taxonomic rank or* a unit at that rank ....
in about 140
generaIn biology, a genus is a taxonomic unit used in the classification of living and fossil organisms. The term comes from Latin genus "descent, family, type, gender" , cognate with – genos, "race, stock, kin" ..In addition, genus is a taxonomic rank in the hierarchy In biology, a genus (plural:...
. The name derives from
LatinLatin is an Italic language originally spoken in Latium and Ancient Rome. Through the Roman conquest, Latin spread throughout the Mediterranean and a large part of Europe...
, and means
those that flee from the sun. The order is also known by the names Solpugida, Solpugides, Solpugae, Galeodea and Mycetophorae. Their
common nameA common name is a name in general use within a community; it is often contrasted with a scientific name...
s include
camel spider,
wind scorpion,
jerrymuglum,
sun scorpion and
sun spider. In southern Africa they are known by a host of names including
red romans,
haarskeerders and
baarskeerders, the latter two relating to the belief they use their formidable jaws to clip hair from humans and animals to line their subterranean nests.
Solifugae are not true spiders, which are from a different order, Araneae.
Solifugae is an
orderIn scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...
of
ArachnidArachnids are a class of joint-legged invertebrate animals in the subphylum Chelicerata. All arachnids have eight legs, although in some species the front pair may convert to a sensory function. The term is derived from the Greek word , meaning "spider".Most arachnids are terrestrial...
a, containing more than 1,000 described
speciesIn biology, a species is:* a taxonomic rank or* a unit at that rank ....
in about 140
generaIn biology, a genus is a taxonomic unit used in the classification of living and fossil organisms. The term comes from Latin genus "descent, family, type, gender" , cognate with – genos, "race, stock, kin" ..In addition, genus is a taxonomic rank in the hierarchy In biology, a genus (plural:...
. The name derives from
LatinLatin is an Italic language originally spoken in Latium and Ancient Rome. Through the Roman conquest, Latin spread throughout the Mediterranean and a large part of Europe...
, and means
those that flee from the sun. The order is also known by the names Solpugida, Solpugides, Solpugae, Galeodea and Mycetophorae. Their
common nameA common name is a name in general use within a community; it is often contrasted with a scientific name...
s include
camel spider,
wind scorpion,
jerrymuglum,
sun scorpion and
sun spider. In southern Africa they are known by a host of names including
red romans,
haarskeerders and
baarskeerders, the latter two relating to the belief they use their formidable jaws to clip hair from humans and animals to line their subterranean nests.
Solifugae are not true spiders, which are from a different order, Araneae. Like
scorpionScorpions are predatory arthropod animals of the order Scorpiones within the class Arachnida. There are about 2,000 species of scorpions, found widely distributed south of about 49° N, except New Zealand and Antarctica...
s and
harvestmenHarvestmen are eight-legged invertebrate animals belonging to the order Opiliones in the class Arachnida, in the subphylum Chelicerata of the phylum Arthropoda. , over 6,400 species of harvestmen have been discovered worldwide, although the real number of extant species may exceed 10,000...
, they belong to a distinct arachnid order.
Habitat
Most Solifugae inhabit warm and arid habitats, including virtually all deserts in both the
EasternThe Eastern Hemisphere, also Eastern hemisphere or eastern hemisphere, is a geographical term for the half of the Earth that is east of the Prime Meridian and west of 180° longitude. It is also used to refer to Europe, Asia, Africa, and Australia, vis-à-vis the Western Hemisphere, which includes...
and
Western HemisphereThe Western Hemisphere, also Western hemisphere or western hemisphere, is a geographical term for the half of the Earth that lies west of the Prime Meridian , the other half being the eastern hemisphere...
s, excluding
AustraliaAustralia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the continental mainland , the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans...
. Some species have been known to live in grassland or forest habitats.
Diet
Solifugae are
carnivorousA carnivore , meaning 'meat eater' , is an animal that derives its energy and nutrient requirements from a diet consisting mainly or exclusively of vertebrate and/or invertebrate animal tissue, whether through predation or scavenging...
or
omnivorousOmnivores are species that eat both plants and animals as their primary food source...
, with most species feeding on
termiteThe termites are a group of eusocial insects usually classified at the taxonomic rank of order Isoptera . Along with ants and some bees and wasps which are all placed in the separate order Hymenoptera, termites divide labour among gender lines, produce overlapping generations and take care of...
s,
darkling beetleDarkling beetles are a family of beetles found worldwide, estimated at more than 20,000 species. Many of the beetles have black elytra. Darkling beetles eat both fresh and decaying vegetation. Major predators include birds, rodents, sunspiders, and lizards...
s, and other small
arthropodAn arthropod is an invertebrate that has an exoskeleton , a segmented body, and jointed attachments called appendages. Arthropods are animals belonging to the Phylum Arthropoda , and include the insects, arachnids, crustaceans, and others...
s, although Solifugae have been videotaped consuming larger prey such as lizards. Prey is located with the pedipalps and killed and cut into pieces by the chelicerae. The prey is then liquefied and the liquid ingested through the pharynx. Although they do not normally attack humans, these chelicerae can penetrate human skin, and painful bites have been reported.
Reproduction
Reproduction can involve direct or indirect
spermThe term sperm is derived from the Greek word sperma and refers to the male reproductive cells. In the types of sexual reproduction known as anisogamy and oogamy, there is a marked difference in the size of the gametes with the smaller one being termed the "male" or sperm cell...
transfer; when indirect, the male emits a
spermatophoreA spermatophore is a capsule or mass created by males of various animal species, containing spermatozoa and transferred in entirety to the female's ovipore during copulation...
on the ground and then inserts it with his chelicerae in the female's genital pore. To do this, he flings the female on its back. The female then digs a burrow, into which it lays 50 to 200 eggs, depending on the species. These are guarded until they hatch. Because the female will not feed during this time, it will try to fatten itself beforehand, and a species of 5 cm has been observed to eat more than 100 flies during that time in the laboratory.
Anatomy
Solifugids are moderate to large arachnids, with the larger species reaching in length. The body is divided into a forward part, or prosoma, and a segmented
abdomenIn vertebrates such as mammals the abdomen constitutes the part of the body between the thorax and pelvis. The region enclosed by the abdomen is termed the abdominal cavity...
. The prosoma is divided into a relatively large anterior carapace, including the animal's eyes, and a smaller posterior section. Like other arachnids, they have eight legs, but the first pair are small, and used to feel the animal's surroundings, so that only the other six legs are used for running.
The most distinctive feature of Solifugae is their large
cheliceraeThe chelicerae are mouth parts of the Chelicerata, an arthropod subphylum that includes arachnids, Merostomata , and Pycnogonida . Chelicerae are pointed appendages which are used to grasp food, and are found in place of the chewing mandibles most other arthropods have...
, which are longer than the prosoma. Each of the two chelicerae are composed of two articles forming a powerful pincer; each article bears a variable number of teeth.
Solifugae also have long
pedipalpPedipalps , 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...
s, which function as sense organs similar to insects'
antennaeAntennae in biology have historically been paired appendages used for sensing in arthropods and crustaceans. More recently, the term has also been applied to cilium structures present in many cell types of eukaryotes....
and give the appearance of an extra pair of legs. The pedipalps terminate in eversible adhesive organs, which are used to capture flying prey, and for climbing. They
stridulateStridulation is the act of producing sound by rubbing together certain body parts. This behavior is mostly associated with insects, but other animals are known to do this as well, such as a number of species of snakes and spiders. A dedicated stridulation apparatus has also been discovered in males...
with their chelicerae, resulting in a rattling noise.
Like
pseudoscorpionA pseudoscorpion, , is an arachnid belonging to the order Pseudoscorpionida, also known as Pseudoscorpiones or Chelonethida....
s and harvestmen, they lack
book lungA book lung is a type of respiration organ used for atmospheric gas exchange and is found in arachnids, such as scorpions and spiders. Each of these organs is found inside a ventral abdominal cavity and connects with the surroundings through a small opening. Book lungs are not related to the lungs...
s, having instead a well-developed tracheal system that takes in air through three pairs of slits on the animal's underside. In some species there are very large central eyes that are capable of recognizing forms, and are used for hunting. Lateral eyes are only rudimentary, if present at all. Males are usually smaller than females, with longer legs.
Urban legends
Solifugae are the subject of many urban legends and exaggerations about their size, speed, behavior, appetite, and lethality. They are not especially large, the biggest having a leg span of perhaps 12 centimeters (5 in). They are fast on land compared to other invertebrates, the fastest can run perhaps , nearly half as fast as the fastest human sprinter. Members of this order of Arachnida apparently have no venom, with the possible exception of one species in
IndiaIndia, 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, and the most populous democracy in the world. Bounded by the Indian Ocean on the south, the Arabian Sea on the west, and the Bay of Bengal...
(see below) and do not spin webs.
In the
Middle EastThe Middle East is a region that spans southwestern Asia, southeastern Europe, and northeastern Africa. It has no clear boundaries, often used as a synonym to Near East, in opposition to Far East...
, it is widely rumored among American and coalition military forces stationed there that Solifugae will feed on living human flesh. The story goes that the creature will inject some
anaesthetizingAnesthesia, or anaesthesia , has traditionally meant the condition of having sensation blocked or temporarily taken away. This allows patients to undergo surgery and other procedures without the distress and pain they would otherwise experience...
venom into the exposed skin of its sleeping victim, then feed voraciously, leaving the victim to awaken with a gaping wound. Solifugae, however, do not produce such an anaesthetic, and they do not attack prey larger than themselves unless threatened. Other stories include tales of them leaping into the air, disemboweling
camelCamels are even-toed ungulates within the genus Camelus. The dromedary or Arabian camel has a single hump, and the Bactrian camel has two humps. They are native to the dry desert areas of western Asia, and central and east Asia, respectively...
s, screaming, and running alongside moving humvees; all of these tales are dubious at best.
Due to their bizarre appearance many people are startled or even afraid of them. This fear was sufficient to drive a family from their home when one was discovered in a soldier's house in
Colchester, EnglandColchester is a town and the largest settlement within the borough of Colchester in Essex, England.At the time of the census in 2001 it had a population of 104,390...
. The greatest threat they pose to humans, however, is their bite in self-defense when one tries to handle them. There is essentially no chance of death directly caused by the bite, but, due to the strong muscles of their
cheliceraeThe chelicerae are mouth parts of the Chelicerata, an arthropod subphylum that includes arachnids, Merostomata , and Pycnogonida . Chelicerae are pointed appendages which are used to grasp food, and are found in place of the chewing mandibles most other arthropods have...
, they can produce a proportionately large, ragged wound that is prone to infection.
Venom controversy
While the absence of venom in Solifugae was long thought a fact, there is a single published study of one species,
Rhagodes nigrocinctus, carried out in India in 1978 by a pair of researchers who did histological preparations of the chelicerae, and found what they believed to be epidermal glands. Extracts from these glands were then injected into lizards, where it induced paralysis in 7 of 10 tests. While this study has never been confirmed, and while other researchers have been unable to locate similar glands in other species, this particular species does appear to possess venom, although it is not known if there is any mechanism for introducing it into prey (recall that the researchers manually injected it into lizards).
Classification
There are twelve families belonging to the order Solifugae:
- Ammotrechidae
Ammotrechidae are a family of solifuges distributed in the Americas and the Caribbean Islands. They include 22 described genera and at least 83 species...
- Ceromidae
- Daesiidae
- Eremobatidae
- Galeodidae
- Gylippidae
- Hexisopodidae
- Karschiidae
- Melanoblossidae
- Mummuciidae
- Rhagodidae
- Solpugidae
The family Protosolpugidae is only known from one fossil species from the
PennsylvanianThe Pennsylvanian is in the ICS geologic timescale the youngest subperiod or upper subsystem of the Carboniferous period. It lasted from roughly to Ma . As with most other geochronologic units, the rock beds that define the Pennsylvanian are well identified, but the exact date of the...
.