Bioacoustics of Chaetopelma

Description: chelicerae without rastellum. Carapace oval, longer than wide; moderately pilose. Cephalic region slightly raised. Eye tubercle weakly raised, small. Eye group rectangular, anterior eye row procurved, posterior slightly recurved. Fovea deep, ranging from slightly recurved to straight. Maxilla with produced anterior lobe, conical; 60–100 cuspules on inner angle; lyra and serrula absent. Labium nearly as long as wide, with several cuspules restricted to centre of labium (20–60 cuspules). Labiosternal junction moderately deep; sigilla oval, distinct and located near junction. Sternum oval with three pairs of small, rounded sternal sigilla; posterior sigilla one or more than its diameter from sternal margin. Palps and legs slender, moderately pilose. Male tibial apophysis comprising two branches; prolateral branch short with adjacent spine; retrolateral branch long and curved, bearing line or cluster of short apical spines. Male metatarsus I slightly curved, bends over or externally to retrolateral branch of tibial apophysis. Scopulae on ventral surface of metatarsi very dense on legs I, II, less dense on legs III, IV; widening distally. Scopulae on tarsi II–IV divided by band of thick setae, wide on tarsi III and IV. Tarsal and metatarsal scopulae with metallic blue-green iridescence in living material (only live C. olivaceum examined). Scopula on retrolateral femur IV absent. Stridulatory setae apparently absent, although Chaetopelma olivaceum possesses opposing lateral scopulae on femora of leg I and palp; scopulae which in Theraphosa blondi (Latreille 1804) and Encyocratella olivacea Strand 1907 function as stridulatory setae ( Marshall et al . 1995 ; Gallon pers. obs.). Superior tarsal claws of males and females without teeth; inferior tarsal claws absent; claw tufts well developed. Tarsi with clavate trichobothria in two parallel dorsal rows along segment, separated by longitudinal line of long, thin setae; filiform and clavate trichobothria are interspersed. Filiform trichobothria on metatarsi (single row) and tibiae (two rows); clavate trichobothria in compact group on cymbium. Tarsi without spines. Cymbium longer than wide, bilobed. Palpal bulb with long, thin embolus, without keels. Spermathecae comprising two long, thin receptacles, either single or bi-lobed apically. Abdomen coloration uniformly brown; abdominal markings absent. Urticating hairs absent. Two pairs of spinnerets; posterior median spinnerets very short; posterior lateral spinnerets with all three segments of similar length and bearing spigots; apical article digitiform. Species included: C. olivaceum ( C. L. Koch 1841 ) ; C. karlamani Vollmer 1997 ; C. concolor ( Simon 1873 ) n. comb.