Spider phalanx

The Phalanx Spider is an unpredictable animal. Few of the desert inhabitants are so perplexing in their behavior and look like aliens. These arachnids have a bad reputation that is exaggerated by myths, superstitions and folk legends. But in fact, they are charming and mysterious animals, whose lifestyle is very different from other species. As frightening as phalanx spiders are in appearance and behavior, they are, fortunately, mostly harmless to humans and pets.

Origin of the species and description

Photo: Phalanx Spider

Photo: Phalanx Spider

The order includes over 1000 described species in 153 genera. Despite common names, they are neither true scorpions (Scorpiones) nor true spiders (Araneae). Disputes about their identity continue by experts. Are they really spiders or scorpions? For now, they will remain in this classification, but future research may lead to changes in status.

This group of arachnids has various common names, phalanxes, salpugs, bihorks, wind scorpions, sun spiders, etc. These distinctive creatures have several common names in English and African, many of which include the term “spider” or even “scorpion”. Although in their biological characteristics, these animals are something between scorpions and spiders.

Video: Phalanx spider

The only obvious similarity they share with spiders is that they have eight legs. Phalanges do not have venom glands and are not a threat to humans, although they are very aggressive, move quickly and can inflict a painful bite. The Latin name “solifugae” comes from “fugere” (to run; fly, run away) and “sol” (sun). The oldest fossil of the order, Protosolpuga carbonaria, was discovered in the USA in 1913 in Late Carboniferous deposits. In addition, samples are found in Burmese, Dominican, Baltic amber and Cretaceous layers in Brazil.

Fun fact: The term “solar spider” is applied to those species that are active during the day. In an effort to avoid the heat, they rush from shadow to shadow — often it is the shadow of a person. The result is an unsettling impression that they are chasing a person.

It appears that the female phalanx considers hair to be an ideal nest material. Some reports said they cut the hair off people's heads without knowing it. However, scientists refute this, the arachnid is not adapted to cut hair, and this statement is to remain a myth. And although salpugs do not fluoresce as brightly as scorpions, they do fluoresce under certain ultraviolet light of the correct wavelength and power.

Appearance and features

Photo: What a phalanx spider looks like

Photo: What a phalanx spider looks like

The body of a saltwort is divided into two parts:

  • prosoma (shell);
  • opisthosoma (abdominal cavity).

The prosoma consists of three sections:

  • propeltidium (head) contains chelicerae, eyes, pedipalps and the first two pairs of legs;
  • mesopeltidium contains a third pair of legs;
  • metapelptidium contains a fourth pair of legs.

Outwardly, it seems that the phalanx spider has 10 legs, but in fact, the first pair of appendages — these are highly developed pedipalps that are used for various functions such as drinking, catching, feeding, mating, and climbing. Only the three rear pairs of legs are primarily used for running. The most unusual feature of — unique organs at the tips of the legs. Some spiders can use these organs to climb vertical surfaces.

The first pair of legs are thin and short and are used as tactile organs (tentacles). The phalanges lack the patella (a leg segment found in spiders, scorpions, and other arachnids). The fourth pair of legs is the longest. Most species have 5 pairs of ankles, while juveniles have only 2-3 pairs. They were supposed to be sensory organs for detecting vibrations in the soil.

The body length varies from 10-70 mm, and the leg span is up to 160 mm. The head is large, supporting large strong chelicerae (jaws). The propeltidium (shell) is raised to accommodate the enlarged muscles that control the chelicerae. Because of this elevated structure, they are often referred to in the English-speaking segment as “camel spiders”. The chelicerae has a fixed dorsal digit and a movable ventral digit, both armed with cheliceral teeth for crushing prey. These teeth are one of the features used in identification.

Some species have very large central eyes. They can recognize shapes and are used for hunting and observing enemies. These eyes are remarkable for their internal anatomy. In many species, lateral eyes are absent, and where they are present at all, they are only rudimentary. The abdomen is soft and expandable, which allows the animal to eat a large amount of food. The body of many species is covered with bristles of various lengths, some up to 50 mm, resembling a shiny hairball. Many of these bristles are tactile sensors.

Where does the phalanx spider live?

Photo: Falanga spider in Russia

Photo: Phalanx spider in Russia

These arachnids are considered endemic indicators of desert biomes and live in very dry conditions. The hotter the better for them. Phalanx spiders survive in remote places where only a handful of living things can live. Their versatility in relation to their habitat is certainly the driving force behind their lives over millions of years. The only surprise is that they do not live in Australia at all. Although this mainland is a very hot place, however, no species has been found there.

The flexibility to the habitat allows the phalanx spider to populate some grasslands and forest areas as well. But even in such regions, they will look for the warmest places to live. On the territory of Russia, they were found on the Crimean Peninsula, the Lower Volga region (Volgograd, Astrakhan, Saratov regions, Kalmykia), as well as in Transcaucasia and the North Caucasus, in Kazakhstan, Kyrgyzstan (Osh region), Tajikistan, etc. In Europe, they are found in Spain, Portugal, Greece.

An interesting fact: There are 12 families, 140 genera and 1075 species of salpuga in the world. And in southern Africa, six families, 30 genera and 241 species are registered. Thus, 22% of the world stock of all phalanx spider species is found in the southern part of the African continent. The Northern Cape (81 species) and Namibia have the largest number of species. The Orange River does not restrict their distribution.

There are over 200 species of Solifugae in the New World. Only two families (Eremobatidae and Ammotrechidae) are found in North America. At least three species occasionally migrate to southern Canada. However, the zenith of Phalanx spider diversity is the Middle East.

Now you know where the Phalanx spider is found. Let's see what he eats.

What does the phalanx spider eat?

Photo: Poisonous Phalanx Spider

Photo: Poisonous Phalanx Spider

The insect never misses an opportunity to eat, even when the arachnid does not feel hungry. The animal accumulates fat on the body in order to survive those times when food becomes scarce. Phalanx spiders eat both living insects and those that have been found dead. They may consume snakes, lizards, rodents, beetles, and termites. However, what they will eat often depends on the location and time of year. They don't seem to have a problem foraging for food that is smaller than them. Salpugs mainly go hunting at night.

All species of phalanx spider are carnivorous or omnivorous. They are aggressive hunters and voracious eaters of everything that moves. Prey is found and captured by pedipalp tentacles, and killed and cut into pieces by chelicerae. The prey then liquefies and the liquid enters the mouth. Although they do not normally attack humans, their chelicerae can penetrate human skin and deliver painful bites.

The phalanx spider's diet consists of:

  • termites;
  • beetles;
  • spiders;
  • scorpions;
  • small land arthropods;
  • snakes;
  • rodents;
  • various insects;
  • small reptiles;
  • dead birds.

Phalanx spiders can prey on other predators such as bats, toads, and insectivores. Some species are exclusively termite predators. Some individuals sit in the shade and ambush prey. Others catch the prey and eat it while it is still alive, vigorously tearing the flesh with sharp movements of powerful jaws. In addition, the phalanx spider has cannibalism, they always attack their relatives and the strongest wins.

Peculiarities of character and lifestyle

Photo: Falanga spider in Astrakhan

Photo: Falanga spider in Astrakhan

Phalanx spiders are mostly nocturnal, but there are diurnal species that are usually brighter colors with light and dark stripes along the entire length of the body, while nocturnal species are yellowish brown and often larger than diurnal ones. Watching the phalanx, their crazy speed immediately becomes apparent. Because of her, they received the name “scorpion-wind.” They move over rough terrain or soft sand, which causes most other animals to get stuck or slow down. Phalanxes are also surprisingly good climbers.

Camel spiders are well adapted to arid environments. Covered with fine hairs, they are insulated from the heat of the desert. The sparse, longer bristles act as sensors to help locate prey when touched. Thanks to special receptors, they literally look for information about the substrate through which the animal passes and can even detect underground prey at shallow depths. This is one of the spider species that is difficult to spot. Not only do they have excellent camouflage, but they also love to hide. They can be found in any dark corner or under piles of planks or rocks.

Interesting fact: The phalanx spider is one of the fastest. It can move at a speed of 16.5 km per hour. But usually moves much more slowly when not in danger, and he does not have to rush to leave the danger zone.

Salpuga are difficult to get rid of because of the many hiding places they find in the house. Some families had to leave their homes after all attempts to successfully eradicate these camel spiders failed. Some species can make a hissing sound when they feel they are in danger. This is a warning to be able to get out of a difficult situation.

Social structure and reproduction

Photo: Falanga spider in Kazakhstan

Photo: Falanga spider in Kazakhstan

Given their general aggressiveness, the question arises of how phalanx spiders reproduce without killing each other. Indeed, the “rapid approach phase” during courtship can be mistaken for an attempt at cannibalism. The female may push away the challenger and run away or adopt a submissive posture. The male grabs her by the middle of her body and massages her with his jaws, and also strokes her with pedipalps and the first pair of legs.

He may pick her up and carry her a short distance, or simply continue courting at the initial point of contact. He eventually secretes a drop of sperm from his genital opening, presses it against his jaws, and uses his chelicerae to force the sperm into the woman's genital opening. Mating rituals vary among different families and may involve direct or indirect transfer of sperm.

Fun fact: Phalanx spiders live fast and die young. Their average life expectancy is barely more than one year.

The female then digs a hole and lays her eggs and leaves them in the hole. Batches can range from 20 to 264 eggs. Some species guard them until they hatch. About eleven days after being laid, the eggs hatch. Offspring go through eight instars before reaching adulthood. Transitional age — is the interval between molts. Like all arthropods, phalanx spiders must periodically shed their exoskeleton in order to grow.

Natural enemies of the phalanx spider

Photo: What a phalanx spider looks like

Photo: What a phalanx spider looks like

Although most often considered voracious predators, phalanx spiders can also be an important addition to the diet of many animals found in arid and semi-arid ecosystems. Birds, small mammals, reptiles, and arachnids are among the animals recorded as predators of the salt pug. The phalanges have also been observed feeding on each other.

Owls are probably the most common birds of prey, preying on large phalanx species. In addition, New World vultures and Old World larks and wagtails have been observed preying on these arachnids. In addition, remains of a chelicerae have also been found in bustard droppings.

Several small mammals include phalanxes in their diet:

  • big-eared fox (O. megalotis);
  • common genet (G. genetta);

  • South African fox (V. chama);
  • African civet (C. civetta);
  • black-backed jackal ( C. mesomelas).

Phalanxes have been found to be the fourth most common prey item for the Texas striped gecko (Coleonyx brevis), after termites, cicadas, and spiders. Some researchers claim that African reptiles feed on them, but this has not yet been confirmed.

Arthropod predators on the spider phalanx are not easily quantified. Two cases of arachnids (Araneae) predators have been recorded in Namibia. Nearly every story about violent fights between phalangeal spiders and scorpions is fiction. These messages are connected with the influence of man on the confrontation of these animals, organized in special conditions. In natural environments, the degree of their aggressiveness towards each other is unclear.

Population and species status

Photo: Phalanx spider in Crimea

Photo: Phalanx spider in Crimea

The desert lifestyle of the phalanx spider does not allow us to accurately determine the prevalence of populations of its species. Solifugae — have become the subject of many myths and exaggerations about their size, speed, behaviour, appetite and bite lethality. Members of this order have no venom and do not spin webs.

Interesting fact: The phalanx spider is generally believed to feed on living human flesh. The mythical story says that the creature injects some kind of anesthetic poison into the exposed skin of a sleeping victim, and then voraciously feeds on their flesh, as a result, the victim wakes up with a gaping wound.

However, these spiders do not produce such an anesthetic, and like most creatures with a survival instinct, they do not attack prey larger than themselves, except in a defense or offspring situation. Due to their bizarre appearance and the fact that they make a hissing sound when they feel threatened, many people are afraid of them. However, the biggest threat they pose to humans is — this is their bite in self-defense.

The phalanx spider leads a violent lifestyle, therefore it is not recommended as a pet. The nomadic lifestyle sometimes brings the phalanx spider into houses and other dwellings. There is no cause for alarm, so the arachnid can be placed in a container and taken outside. Not a single death has been recorded directly caused by the bite, but due to the strong muscles of their chelicerae, they can make a proportionately large, lacerated wound in which infection can develop. Only one species, Rhagodes nigrocinctus, has poison, but its bite is not harmful to humans.

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