Whipscorpions

Uropygi

Classification

Phylum: Arthropoda
Subphylum: Chelicerata
Class: Arachnida
Order: Uropygi

Pronunciation

How to pronounce Uropygi: /ˌjuːroʊˈpaɪdʒiː/

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Summary

Uropygi, commonly known as whip scorpions or vinegaroons, are a unique order of arachnids characterized by their long, whip-like tails and pincers. They are nocturnal predators that play an important role in their ecosystem.

Physical Characteristics

Whip scorpions range from 25 to 85 mm in length, with most species having a body no longer than 30 mm. They possess a long whiplike tail that is a sensory organ, large scorpion-like pincers (pedipalps), and specialized secondary sensory organs (first pair of legs). The opisthosoma consists of 12 segments, with the last three segments fused to form a closed ring that ends with a flagellum composed of 30-40 units.

Identification Tips

Distinguished from true scorpions by their inability to sting and their long, whip-like tail that serves as a sensory organ rather than a weapon. They have large, pinching mouthparts and modified front legs for sensory purposes.

Habitat

Tropical and subtropical areas, usually found in humid, dark places. They often dig burrows or take shelter under logs, rotting wood, rocks, or other natural debris.

Distribution

Primarily in tropical and subtropical regions worldwide, with three species in the U.S. (Arizona, Texas, and Florida). A single species is known from Africa: Etienneus africanus endemic to Senegal, Gambia, and Guinea-Bissau.

Diet

Carnivorous, primarily feeding on insects, millipedes, scorpions, and terrestrial isopods. Some species may also consume small vertebrates.

Life Cycle

Young hatch as postembryos, climb onto the mother's back, and remain there until the first moult. They take about four years to reach adulthood after four moults. The female may live for up to two additional years after giving birth.

Reproduction

Males transfer a spermatophore to females following courtship. Females then develop eggs in a broodsac attached to their genital area and refuse to eat while protecting the eggs until hatching.

Ecosystem Role

Controlling the populations of cockroaches and crickets.

Evolution

Part of a group that includes Amblypygi and Schizomida. Phylogenetic studies suggest divergence from related groups occurred in the late Carboniferous.

Similar Taxa

Misconceptions

Often mistaken for true scorpions; however, they lack venom glands and cannot sting.