Hooded Tickspiders

• It has a movable hood, the cucullus, which lowers like a visor to cover the mouth and mouthparts when it is not feeding, a structure found in no other arachnid.
• The male uses one of his third pair of legs, modified into a copulatory organ, to transfer sperm, something unheard of among arachnids.
• It is so rare that for decades it was known only from a handful of museum specimens, and several species of the order have been described in the twenty-first century.
• It belongs to the Ricinulei, one of the least studied arachnid orders in the world: the order was discovered in 1838 and in almost two centuries barely a hundred species have been described.
• It is neither a spider nor a tick, despite the name hooded tickspider. Its abdomen is segmented, unlike a spider's, and it has no eyes.
• Its most characteristic feature is the cucullus: a hinged hood that folds down over its chelicerae and covers its mouth, and which it raises to feed.
• Being blind, it navigates with its chelicerae and its very long second pair of legs, which it uses as feelers.
• In the males the third pair of legs is modified into a copulatory organ, and its shape is what allows genera and species to be told apart.
• Like ticks and mites, the young hatch with six legs and the fourth pair appears later.
• They are so poorly represented in collections that almost any new find turns out to be a new species.

Skeleton type

Invertebrate - chitin exoskeleton (arachnid)

Habitat and environment

Damp leaf litter and caves of the rainforest of Panama and Central America

Sources consulted: Botero-Trujillo et al. (2021), American Museum Novitates · Cooke (1967), Journal of Zoology · Pittard y Mitchell (1972)