A scissors-like organ carried by many lobsters on the first pereiopods, sometimes also found on some or all of the other pereiopods, sometimes entirely lacking. The chela is formed by the last two segments of the leg, viz., propodus and dactylus, and consists of a palm and two fingers. The upper or movable finger is formed by the dactylus, which articulates with the propodus at the end of the palm; it opposes the fixed finger, which is immovably connected with the palm and forms with it the propodus. The opposing edges of the two fingers, the cutting edges, may carry teeth. The presence or absence of chelae, as well as their shape, size and ornamentation, can be of great taxonomic value. The Nephropoidea have chelae on the first three pairs of pereiopods, the first of which usually is very large. In the Palinuroidea the first four legs have no true chelae, but the females of most species have a small chela on the fifth pereiopod. The Thalassinidea sometimes have a true chela on the first and second pereiopods, but often they only have a subchela.

Alternative forms for chela : chelae, pincer.