Myths, Bites, and Habitats,
By Anders Nielsen, Ph.d.
The camel spider belongs to the order Solifugae of the class Arachnida. It is related to both spiders and scorpions but is neither.The Greeks were the first to recognize camel spiders as an individual group of animals and gave them the name phalangium because they appear to have five legs.[1].
Camel Spiders vs. Scorpions and Insects
Camel spiders are related to the other arthropods, but several hundred million years ago a divergence occurred between the two lines. They really are different; for example, the breathing system of camel spiders is similar to that observed in insects.[2].
This breathing system is with trachea, which allows for a relatively fast oxygen uptake when necessary, and hence the ability to move fast.
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They are not dangerous, but because of their appearance and the many myths circulating about them, primarily made up by soldiers deployed in Iraq and Afghanistan, camel spider have a reputation as brutal and merciless desert animals.
Californian Camel Spider
This video is probably from California. It is a family camping in the desert, and the guy finds a camel spider in a bag. You can see how the camel spider seeks the shade all the time, and that it is rather fast. It is not very big either, and it is absolutely not dangerous to humans.
Camel Spider Eating a Mouse
This video shows a full grown camel spider eating a small mouse. As the video in the video section also shows, camel spiders are capable of catching and killing fairly large animals. Its strong chelicerae allow it to crush any prey of a reasonable size it encounters. As they are rather fast, they have no problem tracking down a hurt or unwary animal or even ambushing a fast moving animal. Since camel spiders only eat meat, they are not interested in leafs, etc. The movements it makes while eating is to breathe through its trachea. The type of species in this video (Rhagodes) is not found in the USA, but they can be imported as pets.
Man eats camel spider
Camel spider fight
Camel spiders are also known as sun spiders, beard cutters (due to their large jaws), wind spiders, and wind scorpions. The name solifugid means “escaping from the sun,” which is very characteristic of camel spiders in terms of behavior.
USA Distribution
There are two families of Camel spiders in North America. Both contain numerous sub-species. However, as camel spiders are only found in deserts, grasslands and beach dunes. On a micro-habitat level habitats that are considered xeric. In the 2006 issue of Journal of Arachnology[5], a list with places where camel spiders were found is listed. The places where you are most likely to eoncounter a solifugae are: California, Texas, New Mexico, Texas, Colorado, Nebraska, Wyoming, Oklahoma, Nevada, Montana, North Dakota and South Dakota.
Myths About Camel Spiders
The myths circulating about their size, that they can grow as large as dinner plates, never disappear because of the infamous hoax image showing two camel spiders tied together.
The hissing sound they can make also generates various myths. It creates the hissing sound by a stridulatory organ.[3].
A recent study showed that the stridulatory organ had a similar morphology in all developmental stages of the camel spider. The conclusion from the study was that the hissing had a defensive purpose (ibid).
Habitat - Fleeing From the Sun
Camel spiders prefer dry, sandy areas and are found in Northern Africa and in the Middle East, including Iraq and Afghanistan. In these semi-arid environmental conditions they follow the shade whenever their sensory organs sense it.
Camel spiders, like solifugids, are nocturnal animals. Soldiers claim that camel spiders chase people in the Iraqi desert but it is, of course, the shadow that the animals are seeking.
Bites
Camel spiders are neither dangerous nor venomous, and humans have nothing to fear from them. The myth about how dangerous camel spider bites are is purely an anecdote. Although a bite is probably painful, only the bacteria in its mouthpart is capable of hurting you.
Diet
Camel spiders are carnivorous and eat a variety of animals that they kill with their strong chelicerae. Its diet includes small rodents, spiders, insects, termites, and small reptiles.
They are not strong enough to capture and kill large mammals, but occasionally they catch undersized birds.
Hunting
Camel spiders can move at velocities of almost ten miles per hour. Their oxygen uptake capacity is high, which explains why they can move that fast. A side-effect of their high metabolic activity is a short life-span.
Fight Between Camel Spider and Scorpion
Obviously, it is not American soldiers who arranged the battle.
Appearance
When stretched out, camel spiders can reach a length of five inches, although the average size is somewhere between one-half inch to three inches. Their abdomens have 11 segments, and there is no intermediary segment separating the head from the abdomen. They have two clearly visible eyes and five so called “racket organs.” These organs are probably rudimentary eyes, as scorpions have five very small eyes.
Camel spiders are covered with hairs and spines that allow them to move quickly and sense vibrations in their surroundings.
Mating Behavior
In his study from 1966, Martin Huma[4] divided the mating habits of solfugids into three phases. The first phase is the attack phase, the second phase is the contact phase, and the third phase is the transfer phase. In the attack phase, either the male or female assumes an attacking position by raising the first pair of legs. In this phase, the male initiates the contact phase by a jump forward towards the female. This either results in a combat between the two or a complete submission by the female where the male grabs her with his chelicerae. If she does not fight him so much that he flees, the male will copulate with the female to impregnate her with offspring.
The presented phylogenetic tree indicates how camel spiders share the same common ancestor as spiders and scorpions.
Systematics of Arachnids
The Solifugae Order and Its Evolution
The picture above shows how camel spiders are related to both scorpions and true spiders. It is obvious that they are more closely related to scorpions.
Arachnida consists of ten orders (see below) of which the camel spider (solifugae) is one of them. Within the camel spiders, there are approximately 900 species in six different families.
Table: Various orders Within the Class Arachnida
| Acari | Mites and ticks |
| Araneae | True spiders |
| Opiliones | Harvestmen |
| Palpigradi | Micro-whip scorpions |
| Pedipalpi | Whip Scorpions |
| Pseudoscorpiones | Pseudoscorpions |
| Ricinulei | Ricinulids |
| Scorpiones | Scorpions |
| Solifugae | Camel Spiders |
Camel Spiders vs. Spiders and Scorpions
Although camel spiders look similar to spiders and scorpions, they are different. They do not have venom or silk glands, and they kill and chew their prey with their powerful jaws.
References
1 Fred Punzo, The biology of Camel-spiders (Arachnida, Solifugae) (1998)
2 Lighton & Fielden, Gas Exchange in Wind Spiders (Arachnida, Solphugidae): Independent Evolution of
Convergent Control Strategies in Solphugids and Insects. J. of Insect Physiol Vol 42(4), pp 347-357 (1996)
3 Hruskova-Martisova et al., Analysis of the stridulation in solifuges (Arachnida : Solifugae).
J. of insects behavior 21(5) pp. 440-449 (2008)
4 Muma, Martin H., MATING BEHAVIOUR IN THE SOLPUGID GENUS EREMOBATES BANKS.
J. of Animal Behaviour 14(2&-3) pp. 346-350 (1966)
5 Jack O. Brookhart and Irene P. Brookhart, Annotated Checklist of Continental North American Solifugae with Type Depositories,Abundance, and Notes on Their Zoogeography.
J. of Arachnology 34(2) pp. 299-330 (2006)
Web resources
BBC video
Sun scorpions in Canada
Scorpions of South Africa
Camel spider picture
C.S. info and pictures
