AW Arachnid Book Whip Spiders Amblypygi Photos & Description

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AW Arachnid Book Whip Spiders Amblypygi Photos & Description

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Amblypygi is an order of invertebrate animals belonging to the class Arachnida. They form a separate order of arachnids alongside the spiders, scorpions and others.
Amblypygids are also known as whip spiders and tailless whip scorpions (not to be confused with whip scorpions that belong to the Arachnid order Thelyphonida). The name "amblypygid" means "blunt rump", a reference to a lack of the flagellum ("tail"). Whip spiders, also known as tailless whip scorpions, are a conspicuous group of bizarre, dorsoventrally flattened arachnids with raptorial pedipalps and a pair of extremely elongate, antenniform first legs. They are harmless to humans. Amblypygids possess no silk glands or venomous fangs. They rarely bite if threatened, but can grab fingers with pedipalps, resulting in thorn-like puncture injury.

They are found in tropical and subtropical regions worldwide. There are 17 genera and 136 species worldwide, with four genera and seven species native to southern Africa. Found mainly in the tropics and subtropics, occurring under rocks, in crevices and under bark.
Genera native to southern Africa:
All these genera are in the family Phrynichidae.
Damon: An African genus of 10 species, four of which are native to southern Africa.
Phrynichodamon: One species, Phrynichodamon scullyi, which is native to South Africa (Northern Cape) and Namibia.
Euphrynichus: Two species with one, Euphrynichus bacillifer, native to southern Africa. Its overall distribution includes Zimbabwe, Malawi, DRC, Angola, Tanzania, Kenya and Madagascar.
Xerophrynus: One species, Xerophrynus machadoi, which is native to Namibia and Angola.

Amblypygids range from 7.6 to 60 cm in size according to legspan. Their bodies are broad and highly flattened, with a solid carapace and a segmented abdomen. They have a pair of median eyes at the front of the carapace, located just above the chelicerae (in a manner somewhat similar to that of crustaceans), and possessed three smaller eye pairs placed further back on each side, for a total of eight eyes.
Amblypygids possess medium to poor eyesight. Their pedipalps, which serve as sensors for many related arachnids, are modified for grabbing and retaining prey, much like those of a mantis. The first pair of legs act as sensory organs and are not used for walking. The sensory legs are very thin and elongate, have numerous sensory receptors, and can extend several times the length of body. Typically, the animal holds one of these legs out in front of it as it moves, and uses the other to probe the terrain to the side.
Amblypygids often move about sideways on their six walking legs, with one "whip" pointed in the direction of travel while the other probes their other sides. Prey are located with these "whips", captured with pedipalps, then masticated with chelicerae.
Courting rituals involve the male depositing stalked spermatophores, which have one or more sperm masses at the tip, onto the ground, and using his pedipalps to guide the female over them. She gathers the sperm and lays fertilized eggs into a sac carried under the abdomen. When the young hatch, they climb up onto the mother's back; any which fall off before their first moult will not survive.
Amblypygids will consume any appropriately sized prey. Most of their diet likely consists of insects. Like many opportunistic predators, amblypygids can survive for two or three weeks without food. Before, during and after molting they generally do not feed. Like any other arachnid, an amblypygid will molt several times during its life.


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Index to Whip Spiders (Order Amblypygi)

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Index to Whip Spiders (Order Amblypygi)

Phrynichidae (Whip-spiders)
Damon variegatus Tailless Whip-spider


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Re: Index to Africa Wild Insect & Invertebratae Books

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Tailless Whip-spider Damon variegatus
Order: Amblypygi. Family: Phrynichidae

Image © Heksie
Satara, Kruger National Park

Image © Pumbaa
Kruger National Park

The genus Damon is endemic to subsaharan Africa or the Afrotropical region, there are ten species of Damon , which is the most diverse genus of whip spiders on the African continent and includes the largest amblypygid species in the region. Damon johnstonii, Damon medius and Damon tibialis (all formerly placed in the genus Titanodamon ), reach body lengths of 30–40 mm, and their antenniform legs may span 440 mm. Most species of Damon are epigean, spending the day in the cracks and crevices of rock outcrops, beneath stones, exfoliations, the peeling bark of trees, or in the holes of tree trunks, and only venturing out at night in search of prey.

The genus can be divided into two groups. The West African group comprises four large and impressive species – D. johnstonii, D. medius, D. tibialis and Damon uncinatus – ranging from Senegal along the West African coastline to the western part of the Congo, where they inhabit rainforests, caves and mesic savanna. These species are characterised by their large size (30–40 mm) and the presence of ventral sac covers.
The East African or Damon variegatus group is distinguished from the West African group by the absence of ventral sac covers, by their characteristic spermatophores, and by their generally smaller size (25–30 mm). The largest species is D. diadema (reaching nearly 30 mm). Species of this group range from the eastern part of the Congo and Sudan, through Kenya and Tanzania, to South Africa and Namibia, where they occur in a variety of habitats including rainforests, caves, savannas and even the semi-desert of northern Namibia and southern Angola.
Most species of the D. variegatus group are geographically localised. Damon longispinatus is known only from Tanzania. Damon gracilis is restricted to northwestern Namibia and southwestern Angola. Damon annulatipes inhabits forests along the escarpment and eastern coast of South Africa, Swaziland and probably southern Mozambique. Damon diadema is recorded from eastern Tanzania and Kenya, extending northwards into Ethiopia and Somalia. Damon brachialis occurs in Malawi, Mozambique, Zambia and Zimbabwe. Compared to the other species, D. variegatus exhibits a broad distribution from the Congo, through western Tanzania and Zimbabwe, to South Africa and Namibia.

Description
Damon variegatus is one of the larger whip spiders, up to 25 mm. Oval-shaped body, legs extended. It has eight legs with the first pair being referred to as antenniform legs. They are longer than the other three pairs of walking legs. The carapace and abdomen are flattened. The pedipalps (leg-like mouthparts), are spiky in order to hold prey. Males have larger pedipalps; females may be slightly larger in overall size, but have smaller pedipalps. They have four pairs of eyes, one pair at the front of the body and the other three pairs farther back on the sides. It ranges from brown to black to beige in colour.
D. variegatus displays considerable morphological variation across its wide distribution range. Specimens from southern populations are smaller than those from the Congo, and have fewer antenniform leg segments (28–30 tibial segments in South Africa, 29–30 in Zimbabwe, 30–31 in the Congo). Specimens from various populations also differ in the shade, intensity and patterning of their colouration, e.g. Namibian specimens are more vividly coloured than specimens from localities east of the Kalahari sand system.

Distribution
In South Africa, this species is not found on the Highveld south of the Magaliesberg. In the east, below the escarpment, the distribution extends as far south as Grahamstown.

Image

Damon variegatus is very agile and can move quickly and unexpectedly causing consternation and fright to people =O: . These spider-like creatures look very fearsome, but are actually harmless.

Links: Systematics of the Damon variegatus group of African whip spiders (Chelicerata: Amblypygi): Evidence from behaviour, morphology and DNA. Lorenzo Prendini, Peter Weygoldt, Ward C. Wheeler

Image © BluTuna

Image © BluTuna
Balule, Kruger National Park


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