Chelicera


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chelicera

[kə′lis·ə·rə]
(invertebrate zoology)
Either appendage of the first pair in arachnids, usually modified for seizing, crushing, or piercing.

Chelicera

 

one of the first two extremities on the head of arthropods of the subphylum Chelicerata. Chelicerae, which serve to grind and crush food, are located in front of the mouth. In most animals they consist of three segments and are equipped with chelae. In spiders the chelicerae have a clawlike terminal segment, onto which the duct of the poison gland opens. In parasitic ticks and mites the chelicerae often resemble spiny piercing stylets; they frequently bear cutting lobes and hooks, with which the parasite attaches itself to the body of the host. The homologues of chelicerae in Crustacea, Myriapoda, and Insecta are the upper jaws, or mandibles.

References in periodicals archive ?
Each chelicera has one curved terminal denticle, one primary denticle, and intermediate and smaller denticles in between, for a total of approximately 25 denticles.
Chelicera. It is present as follows: light brown, darker in color than legs; dorsal side of movable finger darker than hand; galeal seta present; hand with 5 simple setae; external seta longer than fixed finger; galea with 3 to 5 distal rami; rallum with 3 blades; serrula exterior with 14-17 blades; and fixed finger with 6 teeth, 3 terminal teeth small and acute, and 3 basal teeth large and blunt, these teeth are as large as those of deutonymph.
Chelicera: Fixed finger with 2 large teeth plus 4 smaller teeth between these; distal surface of basal tooth with short blunt tooth ([male]) or low protrusion ([female]); brush at base of fixed finger composed of 10 ([male]) or 7 ([female]) setae (G5A), each densely pilose in distal half; lateral surface with 3 large, lanceolate, terminally pilose setae (Gl); internal face of chelicera with 4 ([male], [female]) short whip-like setae (G4); movable finger serrula composed of 18 ([male]), 17 ([female]) long lamellae, blunt guard tooth present subdistally; 1 large accessory tooth present ([male], [female]) at two-thirds from base of serrula accompanied by smaller tooth basally ([female] only).
Chelicera: Five setae on hand, all setae acuminate; movable finger with one medial seta; fixed finger and movable finger with nine teeth; galea represented by a very slight bump on movable finger; rallum consisting of 7-8 blades, the most anterior blade slightly denticulate, other blades long and well bipinnate.
Chelicera, palpus, and first leg of holotype on microscope slide, SMF cat.
Ventrianal shield vase shaped; chelicera fixed digit with 2 sub apical teeth; Setae r3 less than R1 in length ...........................................
Chelicera with 6 setae and 4-5 lateral microsetae on hand O.
Chelicera 23 long, movable digit with 1 tooth, fixed digit with 2 teeth (Fig.
Chelicerae red-brown, with short white setae on anterior surface, surface granular; chelicera with single thick black seta on anterior surface of paturon, located just distal of cheliceral base; three evenly spaced teeth on promargin, median tooth largest, distal tooth smallest; two teeth on retromargin, close together and subequal in size; small cheliceral keel present; endites pale brown with scattered fine black setae, rounded on anterior margin, with well-developed serrula, straight on retrolateral and posterior margins; prolateral longitudinal ridge extending length of endites; labium brown, slightly wider than long.
Chelicera 150 long; terminating in a claw; dorsal and ventral sides with lobes; with one dorsolateral simple seta (Fig.
Based on Chamberlin's single female, the genus Chinchippus can be recognized by: all the legs having a single tarsal segment, no claws on leg I, stridulating ridges on the mesal surface of the chelicera, lateral plates of the "rostrum" shorter than the median plates, and a recurved cephalothorax.
Chelicera: paturon uniformly chestnut brown with two black sutural patches and about eleven times diameter of AME, distal interior margin of paturon unidentate, promargin with about 15 peg teeth (Heimer 1986, fig.