Tailless Whip-Scorpion

Photo of the Tailless Whip-scorpion, Guab��

Tailless Whip-scorpion, Cave spider (Eng.), Guabá (Sp., Puerto Rico.), Amblypygid, Daemon variegatus (Sci.), Native, Puerto Rico. Common in many arid and tropical areas worldwide.

Photo 2003-2006 St. Louis Zoo. Information compiled by Alan Mowbray, Interpretive Media Writer, EYNF/LEF

General Information

Amblypygids are Arachnids (spiders, ticks and scorpions are also in this group). Amblypygids are also known as Cave spiders and Tailless Whip Scorpions and are spiderlike in appearance.. Due in part to their nocturnal lifestyle and bizarre, frightening appearance, very little is known about this arachnid order. An Amblypygid , the Mexican tailless whip-scorpion was featured in the recent movie Harry Potter and the Goblet of Fire.


The body of the Tailless whip-scorpion is is flat. It has ten legs, and its first legs are very long, thin and whip-like. This Amblyplygid’s pedipalps (pincer-bearing front arms adapted for sensory and predatory use) are spiny and powerful. Whip-scorpions found in the El Yunque National Forest can be quite large (19 to 25 inches/48 to 63 centimeters, including legs) when compared to those found in other tropical areas, possibly because there are no large mammal predators on the island. Adult females are larger than males.


Whip-scorpions are nocturnal, emerging at night to hunt and kill their prey. They eat frogs, small animals, large insects and crustaceans. They capture prey by seizing and holding it with their pedipalps and then killing and eating it with their strong jaws. Although they are Arachnids, they do not have spinnerets (tubular structures used to secrete silk thread) and therefore do not spin webs. Whip-scorpions do not produce venom and are harmless to humans. Whip-scorpions fasten their pedipalps together when they are mating to prevent the female from killing and eating the male when mating is finished.


Amblypygid Tailless whip-scorpions live in caves, crevices and under large boulders at most elevations. Since they are nocturnal they are seldom encountered by humans.

Where to look for this animal in the EYNF

At night in rocky, boulder-strewn areas and caves, adjacent to nature trails.

NOTE: Special permits must be obtained from our Passes & Permits Office before using any El Yunque NF trails at night. A few outfitter companies have these permits and some feature guided night excursions on forest trails. Contact information for these companies can be found in Puerto Rico tourist magazines such as “Que Pasa”.