Chelicerae (Gr. Hele - Claw, Keras - Horn)

Chelicerae are a pair of pincer-like head appendages in spiders, scorpions and other arachnids. They serve to capture and hold prey, as well as to inject venom when biting.

The chelicerae consist of two segments - a fixed basal segment is located behind, and a movable palpate segment with a claw at the end is located in front. Some species also have teeth or spines at the end of the palpous segment.

The movement of the chelicerae is carried out with the help of special flexor and extensor muscles. This allows arachnids to effectively catch and hold prey using chelicerae.

In addition, at the end of the chelicerae in many species there are holes through which, when bitten, poison is injected into the wound of the victim. Thus, chelicerae perform an important function as organs of attack and defense in arachnids.