Tail-less whip scorpion (Phrynichus jayakari)
|Also known as:||tailess whip scorpion, whip spider|
|Size||Total length: 5 - 7 cm (2)|
Body length: 3 - 5 cm (2)
Modified front appendages: up to 25 cm (2)
Phrynichus jayakari has yet to be classified by the IUCN.
The tail-less whip scorpion Phrynichus jayakari is spider-like in appearance and, as the common name of this group of arachnids suggests, it lacks a tail (2).
The body of Phrynichus jayakari is relatively flat, with a narrow waist, and is covered by an undivided carapace that is wider than it is long (3). It has a single pair of eyes at the front of the body and three eyes along both sides (2).
Phrynichus jayakari differs from the other arachnids (a group which includes spiders and scorpions) in that it uses only six of its limbs to walk rather than eight, as the front pair are instead modified into very long sensory organs (2). In spite of its rather threatening appearance, Phrynichus jayakari is in fact totally harmless and does not possess venom glands or a sting (3).
While there is no specific information on the range of Phrynichus jayakari, it is known to have been collected in northern Oman (4) and from the United Arab Emirates (5).
Tail-less whip scorpions generally occur in tropical and sub-tropical regions, where they live under stones, leaves, bark or in rock crevices and caves (4) (6).
Like other members of the Amblypygi (whip spiders and tail-less whip scorpions), Phrynichus jayakari is primarily nocturnal and emerges at night in search of food or a mate (6). It has a sideways ‘crab-like’ walking gait, with one its long modified legs always pointing in the direction it is walking (7). Phrynichus jayakari uses its pedipalps to capture insect prey and also during courtship and mating (7).
Although not much is known about the specific mating rituals of Phrynichus jayakari, in other species of tail-less whip scorpions sperm is generally transferred from male to female via the use of a spermatophore (8). Males first perform an elaborate courtship dance before depositing a spermatophore and manoeuvring the female over it. The sperm is then transferred to the female’s genital opening and is used to fertilise the eggs. The female lays between 6 and 60 eggs, and these remain in a sac attached to the female’s underside until they hatch (7).
Despite there being a market for tail-less whip scorpions as pets, the percentage captured for this purpose is currently thought to pose no threat to the overall population (3).
There are currently no known conservation measures in place for Phrynichus jayakari.
More information on conservation in the United Arab Emirates:
Environment Agency - Abu Dhabi:
This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
- Carapace: in arthropods (insects, crabs etc), the fused head and thorax (the part of the body located near the head) also known as ‘cephalothorax’.
- Fertilisation: the fusion of gametes (male and female reproductive cells) to produce an embryo, which grows into a new individual.
- Nocturnal: active at night.
- Pedipalps: in arachnids (a group including spiders and scorpions), a pair of appendages which are modified for many uses, such as killing and manipulating prey, mating, defence and sensory perception.
- Spermatophore: a capsule or mass of sperm transferred from a male to a female during mating, for example in certain insects, arthropods and cephalopods (octopuses and squids).
ITIS (July, 2011)
- Cooke, F. and Bruce, J. (2004) The Encyclopaedia of Animals: A Complete Visual Guide. Weldon Owen Pty Ltd, Sydney.
- Brusca, R. and Brusca, G. (2003) Invertebrates. Second Edition. Sinauer Associates Inc, Sunderland.
- Weygoldt, P.(2002) Reproductive biology of Phrynichus dhofarensis (Chelicerata, Amblypygi, Phrynichidae). Zoologische Anzeiger, 241: 305-315.
- Hellyer, P. and Aspinall, S. (2005) The Emirates: A Natural History. Trident Press Limited, United Arab Emirates.
- Harvey, M. (2003) Catalogue of the Smaller Arachnid Orders of the World: Amblypygi, Uropygi, Schizomida, Palpigradi, Ricinulei and Solifugae. CSIRO Publishing, Melbourne.
- Barnes, R. (1987) Invertebrate Zoology. Fifth Edition. CBS College Publishing, Philadeplphia.
- Weygoldt, P. (1999) Spermatophores and the evolution of female genitalia in whip spiders (Chelicerata, Amblypygi). The Journal of Arachnology, 27: 103-116.