Chelic

Chelic is an informal term that may be encountered in discussions of arachnid anatomy or chelicerate biology, referring to chelicerate mouthparts or the chelicerae. The word derives from Greek chele, meaning claw, and is related to chelicera, the primary feeding appendages of chelicerates such as spiders, scorpions, and horseshoe crabs. In most scientific contexts, the full terms chelicera or chelicerate are used; chelic as an abbreviation appears mainly in informal notes, figure labels, or teaching materials.

Anatomy and function: In chelicerates, the chelicerae are a pair of appendages located near the mouth. They typically consist of a fixed basal segment and a movable distal segment ending in a claw or fang. The chelicerae are used for grasping, piercing, or injecting venom, depending on the lineage. For example, in spiders and some scorpions, the chelicerae drive venom through fangs; in other chelicerates they function more like cutting or tearing tools.

Relationship to broader groups: The term chelic does not denote a taxonomic unit by itself; it is a shorthand reference to the chelicerae or to chelicerates in casual usage. The broader clade Chelicerata includes spiders (Araneae), scorpions (Scorpiones), harvestmen (Opiliones), mites and ticks (Acari), and horseshoe crabs (Xiphosura).

Etymology: from Greek chele, claw. See also Chelicera, Chelicerata, spider venom apparatus.