pedipalper

Pedipalpers are a pair of appendages found on the cephalothorax of arachnids, located near the mouth. They are homologous to the antennae of insects. In many arachnid species, pedipalpers are chemosensory, meaning they are used to detect smells and tastes, aiding in locating prey and mates. They can also be used for manipulating food.

The form and function of pedipalpers vary greatly among different arachnid orders. In scorpions, they are greatly enlarged and modified into formidable pincers used for defense and capturing prey. In spiders, pedipalpers are typically smaller and less conspicuous, though in male spiders they are modified into specialized structures for sperm transfer during mating. These modified pedipalpers in male spiders are often referred to as palpal organs. In some mites and ticks, pedipalpers are used for grasping and anchoring. The specific morphology of the pedipalpers can be a key characteristic used in the identification of different arachnid species. They are distinct from the legs, which are primarily used for locomotion.