John Cancalosi/Peter Arnold, Inc.
The body of most tailless whipscorpions is less than 5 cm (2 in) long, but the foremost pair of legs is extremely long, up to 25 cm (10 in). The cephalothorax, or foremost body section, is covered by a carapace (shell-like covering) and is wider than it is long. The tailless whipscorpion has one pair of eyes toward the front of the cephalothorax and three pairs of eyes on the sides. The long, feeler-like front legs are important sensory organs for hunting and orientation at night. The tailless whipscorpion walks sideways with these legs leading the way. Its pedipalps, or leg-like mouthparts, are stout and spiny and are used to capture and hold insect prey while it is torn apart by the chelicerae, or fangs. Tailless whipscorpions are not venomous and are harmless to humans. They breathe through two pairs of layered lungs, known as book lungs, located within the abdomen.
The male tailless whipscorpion courts the female with trembling movements of his long first pair of legs. He deposits a spermatophore, or sperm packet, and guides the female over it with his pedipalps or with his front legs. She then inserts it into her sex duct. She broods 6 to 60 eggs in a membranous sac until they have hatched and then carries the young on her back until their second molt.
Scientific classification: Tailless whipscorpions make up the order Amblypygi, class Arachnida, phylum Arthropoda. As arachnids, their relatives include true spiders, true scorpions, and the ticks and mites. Tailless whipscorpions should not be confused with whipscorpions (vinegaroons), more elongate arachnids with a whiplike tail, nor should they be confused with the windscorpions (solpugids), which have enlarged chelicerae.