New records of pseudoscorpions from the Juan Fernandez Islands (Chile), with the description of a new genus and three new species of Chernetidae (Arachnida: Pseudoscorpiones). Author Mahnert, Volker text Revue suisse de Zoologie 2011 2011-03-31 118 1 17 29 journal article 10.5962/bhl.part.117795 0035-418X 6114954 AC108FC8-1CDB-4340-A5C1-FDA28A563006 Chelanops gracilipes sp. n. Figs 4-8 MATERIAL STUDIED: MHNG holotype ♀ ; Chile , Juan Fernandez Islands , Masatierra , forest above Puerto Ingles , 14.XI.1968 , leg. H. Franz (Sa 197-198) . DIAGNOSIS: The new species is characterized by its large size (length of palpal femur 1.40 mm , length of chela 1.57 mm ), by the chelal hand being only 1.3 times longer than finger, and the very slender legs (e.g. femur+patella of leg IV 5.2 times, tibia 6.7 times, tarsus 7.6 times longer than broad). DESCRIPTION: Cephalothorax in anterior half reddish brown, basal half yellowish brown, pedipalps dark reddish brown, tergites brown. Cephalothorax 1.2 times longer than broad; no eyes or eyespots; laterally finely granulate, central part smooth; with two granulate transverse furrows, median furrow laterally curved forward, basal furrow narrower and situated halfway between median furrow and posterior margin; setae short, dentate and slightly clavate, 12 setae at posterior margin plus 17 in metazone; metazone with small central depression (groove). Tergites I-X distinctly divided, setae dentate and clavate, longer on posterior tergites, half-tergites with about 7 (6-9) setae on posterior margin, I-IV with 1 median, 1 lateral and 1 discal seta, V-X with 1 median seta, 1-2 lateral setae and 3-5 discal setae, XI with 16 setae (2 lateral tactile and 4 discal setae). Manducatory process with 3 marginal (suboral seta short) and 4 discal setae, coxae of legs with numerous setae. Spermatheca with paired tubes enlarged in distal two-thirds (Fig. 7); anterior genital operculum with about 40 smooth and acute setae; sternites divided, setae long, acute and finely dentate, chaetotaxy of half-sternites: III 11/12+3 suprastigmal setae, IV 7+1 suprastigmal seta, V-X 10+2 medial+1 lateral setae-12+2+1+2 discal setae-6+2+1+6-10+2+1+2-10+2+2+5- 7+2+1+3; entire XI with 10 (2 lateral and 2 submedial tactile setae). Anal cone 2+2 setae. Chelicera with 7 setae on hand, basal three dentate; fixed finger with 6 retrorse teeth, movable finger with tooth-like subapical lobe; galea long, with 6 apical/subapical curved branchlets; serrula exterior with 26 lamellae; rallum with 4 setae, anterior one dentate. Pedipalps (Figs 4-5) rugose but not granulate, setae short, dentate and weakly clavate; trochanter with high dorsal hump, 1.8 times longer than broad, femur increasing in breadth distally, 3.1 times longer than broad, patella 2.5 times, club 1.8 times longer than broad and 2.5 times longer than pedicel, hand with pedicel 1.7 times longer than broad and 1.3 times longer than finger, chela with pedicel 2.8 times, FIGS 4-8 Chelanops gracilipes sp. n. , ♀ holotype . (4-5) Left pedipalp, setae of fingers omitted; with some vestitural setae at higher magnification. (6) Trichobothrial pattern. (7) Spermatheca with right cribrate plate (ventral view). (8) Left leg IV. Scale units 0.1 mm . without pedicel 2.6 times longer than broad; finger 1.3 times longer than hand breadth, fingers not gaping when closed, fixed finger with 57 teeth plus 13 antiaxial (=lateral) and 6 paraxial (=medial) accessory teeth, movable finger with 60 teeth plus 11 antiaxial plus 6 paraxial accessory teeth; nodus ramosus in movable finger slightly proximal to t. Trichobothria (Fig. 6): est opposite ist in middle of fixed finger, it proximal to et and nearer to finger tip than to ist ; st on movable finger nearer to t than to sb . Leg I: femur 1.65 times, patella 3.5 times longer than deep and 1.7 times longer than femur, tibia 5.4 times longer than deep and 1.1 times longer than tarsus, which is 7.15 times longer than deep; leg IV (Fig. 8): femur+patella 5.2 times, tibia 6.7 times longer than deep and 1.3 times longer than tarsus, tarsus 7.6 times longer than deep, tactile seta (length 0.19 mm ) in distal half (TS=0.67); subterminal setae smooth, curved, claws smooth and longer than undivided arolia. MEASUREMENTS (in mm): Body length 5.2; cephalothorax 1.35/1.16; pedipalps: trochanter 0.79/0.45, femur 1.40/0.45, patella 1.37/0.55, hand with pedicel 1.57/0.94, finger length 1.22, chela length with pedicel 2.58, without pedicel 2.41. Leg I: femur 0.42/0.25, patella 0.70/0.20, tibia 0.81/0.15, tarsus 0.73/0.10; leg IV: femur+patella 1.28/0.25, tibia 1.12/0.17, tarsus 0.87/0.11. ETYMOLOGY: Latin noun meaning „slender leg“, emphasizing the slender legs. AFFINITIES: The new species seems to be related to Chelanops kuscheli Beier , and differs from it by the more slender legs (e.g. femur+patella IV 5.2 vs 3.7-3.8 times, tibia 6.65 vs 4.7-5 times longer than deep) and relatively longer palpal fingers. Chelanops insularis Beier (Juan Fernandez Islands, Masatierra) has distinctly longer chelal fingers which are, furthermore, strongly curved and slightly gaping when closed. Chelanops atlanticus Beier (from Tristan da Cunha ) has similar slender legs, but is notably smaller (length of palpal femur 0.90 mm vs 1.40 mm ), has a more slender chela (ratio 3.1-3.2 vs 2.8 times), and has trichobothrium est distal of ist .