Solifugae facts for kids

Quick facts for kids Solifugae Temporal range: Late Carboniferous–recent PreЄ Є O S D C P T J K Pg N
Solifuge from Arizona
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Subphylum:	Chelicerata
Class:	Arachnida
Order:	Solifugae Sundevall, 1833
Families
See text

Solifuges are fascinating creatures that belong to the group of arachnids, just like spiders and scorpions. You might know them by their other names, such as solifuges, sun spiders, camel spiders, or wind scorpions. There are over 1,000 different kinds, or species, of solifuges found around the world. Most of them live in dry climates like deserts. They are known for being quick and for their unique appearance. Don't worry, they are not dangerous to humans.

What are Solifuges?

The name "Solifugae" comes from Latin words. Sol means "sun" and fugere means "to flee." So, their name means "those that flee from the sun." These animals have many common names. People call them sun spiders, wind scorpions, or camel spiders. In some places, they are even called "hair cutters" because of old myths. These myths say they cut hair to use in their nests.

Body and Features

Solifuges are medium to large arachnids. Their bodies can be a few millimeters to several centimeters long. The largest species can reach up to 15 centimeters (about 6 inches) including their legs. However, their body length is usually around 5 to 7 centimeters (2 to 3 inches). Some small species are less than 1 centimeter long.

Like spiders, solifuges have two main body parts. The front part is called the prosoma, or head-chest area. The back part is the abdomen, or opisthosoma, which has 10 segments. The abdomen is very flexible and can stretch a lot. This allows them to eat a large amount of food. Unlike spiders, solifuges do not have a narrow "waist" connecting their body parts. They also do not have spinnerets or make silk. This means they cannot spin webs.

The prosoma includes the head, mouthparts, and where the legs and pedipalps attach. It is covered by a shield called a carapace. This shield has three parts. The front part holds their eyes, large jaws (chelicerae), pedipalps, and the first two pairs of legs. The back parts hold the third and fourth pairs of legs. Solifuges do not have a "tail" like scorpions do.

A diagram showing the parts of a solifuge's body

Amazing Jaws: Chelicerae

One of the most striking features of solifuges is their large chelicerae. These are their powerful jaws. In many species, these jaws are longer than the rest of their front body part. Each of the two jaws works like a strong pincer, similar to a crab's claw. They have several teeth, which vary by species.

These jaws are surprisingly strong. They can cut hair or feathers from animals they eat. They can even cut through thin bones of small birds. Many solifuges can make a rattling noise with their jaws. This is called stridulation.

Close-up views of a solifuge's jaws (chelicerae)

Legs and Sensing Tools

Solifuges appear to have five pairs of legs. However, only the four back pairs are considered true legs. Each true leg has seven segments.

The first pair of leg-like parts are actually pedipalps. They only have five segments. Solifuges use their pedipalps like antennae to sense things. They also use them for moving, eating, and fighting. When they walk, their pedipalps are held out to detect obstacles or prey. This makes them look like an extra pair of legs. The front true legs are often smaller and thinner. They also help with sensing, working with the pedipalps. At the tips of their pedipalps, solifuges have a special suction organ. This helps them catch prey, drink water, and climb smooth surfaces. Only the three back pairs of legs are mainly used for running.

On the underside of their last pair of legs, solifuges have unique fan-shaped structures. These are called malleoli, or racket organs. These paired organs are chemoreceptors, meaning they detect chemicals. They are like the special sensing organs found in scorpions. Males often have larger malleoli.

The underside of a solifuge, showing breathing holes (spiracles) and sensing organs (malleoli)

How They Breathe and See

Unlike some other arachnids, solifuges do not have "book lungs." Instead, they have a well-developed tracheal system. This system is like tiny tubes that carry air throughout their body. They breathe air in and out through several small openings called spiracles. These are located on their body and abdomen. They breathe in a special way, similar to insects. They close their spiracles for a while, then open them to exchange gases.

Solifuges have a pair of large central eyes on the front of their head-chest area. These are called median ocelli. They are close together and covered by a dome-shaped lens. These eyes help them see. They also have a pair of smaller, less developed side eyes. These lateral ocelli might help them detect movement or changes in light.

Solifuge eyes with tiny bristles

Solifuges show some differences between males and females. Males are often smaller and have longer legs. Males also have a pair of flagella, which look like backward-curling bristles. These are found on each jaw (chelicera). Scientists believe these flagella are related to mating, but their exact purpose is still being studied.

A male solifuge in South Africa. Notice the flagella near the tips of its jaws.

Resting Periods: Diapause

Solifuges sometimes go through periods of rest. This is called diapause. During diapause, they become less active. They do this when conditions are not good for them, such as during heavy rain or cold weather. This resting helps them survive until better times. Scientists are still learning a lot about this behavior.

Where Solifuges Live

Most solifuges live in warm, dry places. You can find them in the tropics and subtropical deserts. They live in the Americas, Southern Europe, Africa, the Middle East, and South Asia. Interestingly, you won't find these animals in Australia and Madagascar.

Within deserts, solifuges live in many different small areas. These include sand dunes, flat sandy areas, floodplains, and rocky hillsides. Some also live in desert shrublands and mountain valleys. Besides deserts, some solifuges live in dry grasslands and forests.

Some solifuge species stay in one place. These often dig burrows underground and live there. Other species move around a lot. They spend most of their time on the surface. They might hide in cracks or under rocks and plants when they need shelter.

Life and Habits

What Solifuges Eat and How They Hunt

Solifuges are carnivores, meaning they eat meat. They are not picky eaters and will hunt a wide variety of prey in their environment. For most species, insects make up most of their diet. However, they are known to eat almost anything they can catch. This includes other arachnids like spiders and scorpions. They also eat other arthropods like millipedes. Sometimes, they even catch small lizards, birds, and mammals. Solifuges are very hungry eaters. Adult females sometimes eat so much they can't walk for a while!

When searching for food, most solifuges move quickly, tapping their pedipalps on the ground to feel their way. Some species, like those that eat termites, prefer to stay still. Solifuges use many senses to find prey. They see movement with their eyes, feel with bristles, smell with their malleoli, and sense vibrations. The senses they use most depend on the species. While all hunt on the ground, some are good climbers, finding prey on trees, shrubs, and buildings.

A Gluvia dorsalis solifuge eating a cabbage bug.

Solifuges hunt their prey using three main ways: stalking, chasing, or ambushing. They grab prey with their pedipalps or strong jaws (chelicerae). If using pedipalps, they catch prey with suction cups. Then, they quickly pull it to their jaws to chew. These movements are very fast. Before eating, solifuges often remove hard parts like insect heads or wings.

Solifuges eat food differently based on its shape. Long prey is chewed from one end. Rounder prey is chewed by rotating their body. This chewing turns food into a liquid paste, which they then swallow. Solifuges that are very hungry eat faster. Larger solifuges also eat faster than smaller ones.

Life Cycle and Reproduction

Solifuges usually reproduce once a year. During mating, the male transfers a special packet of sperm to the female. He uses his jaws (chelicerae) to do this.

After mating, the female digs a burrow. She then lays 50 to 200 eggs inside. Some species will guard their eggs until they hatch. The female does not eat much during this time. So, she tries to eat a lot beforehand to store energy. One female solifuge was seen eating over 100 flies in the lab before laying eggs. Solifuges go through several stages as they grow. These include egg, postembryo, several nymph stages, and finally, adults.

Classification

Solifuges are an order of arachnids. There are over 1,200 species in 146 genera. These are grouped into 16 different families. Scientists divide solifuges into two main groups, or suborders. These are the Australosolifugae, which mostly live in the Southern Hemisphere. The other group is the Boreosolifugae, which mostly live in the Northern Hemisphere. This suggests that these groups came from different ancient landmasses.

Solifuges and People

People have known about solifuges for a very long time. Ancient writers mentioned "four-jawed spiders." There are even old stories about them causing problems in desert areas. During World War I and World War II, soldiers in places like Egypt and Libya would sometimes watch fights between solifuges and scorpions for entertainment.

A scorpion (left) fighting a solifuge (right)

Clearing Up Myths: Urban Legends

Solifuges are the subject of many exaggerated stories. These stories often make them seem much bigger, faster, hungrier, or more dangerous than they are.

• Size: They are not especially large. The biggest ones have a leg span of about 12 centimeters (5 inches).
• Speed: They are fast for invertebrates, reaching speeds of about 16 kilometers per hour (10 mph).
• Venom: Solifuges do not have venom glands. They also don't have fangs like spiders or stingers like scorpions to deliver venom. So, they are not venomous.
• Bites: While a large solifuge might give a painful nip with its strong jaws, it's not medically serious. There's no evidence of them causing significant harm to humans.
• Chasing people: If a solifuge seems to be chasing you, it's actually trying to stay in your shadow! They prefer to stay out of direct sunlight.

Because of their unusual spider-like look and quick movements, solifuges can sometimes startle people. But remember, they are harmless to humans.

See also

In Spanish: Solífugos para niños