Cybella bedosae, Judson, Mark L. I., 2017

Judson, Mark L. I., 2017, A new subfamily of Feaellidae (Arachnida, Chelonethi, Feaelloidea) from Southeast Asia, Zootaxa 4258 (1), pp. 1-33 : 14-20

Cybella bedosae n. sp.

Figs 48 , 50‒87

Diagnosis. Very similar to C. deharvengi n. sp., but larger (e.g. male palp femur length 0.573 versus 0.493–0.522 mm), with chela less robust (4.8 times longer than broad, versus 4.3–4.5), most segments of legs more attenuate (e.g. femur of leg IV 2.8 times longer than broad, versus 2.0–2.1), trichobothrium sb slightly proximad of pit (versus below pit), trichobothria eb and esb separated by more than one bothridial diameter (versus half a diameter), anterior genital sternite with 12 setae (versus 8), and lateral diverticulum of male atrial plate of longer.

Etymology. This species is named after Anne Bedos (MNHN), who helped collect the types and who has contributed much to our knowledge of the soil and cave faunas of SE Asia.

Type material. Holotype: ♂, Cambodia, Kampuchea, Kampot, Phnom Laang, Kien Krol , 1042ʹ14.4ʺN 10420ʹ41.1ʺE, 45 m a.s.l., Berlese extraction of soil from low passage (“boyau”) on left side of cave, 20 November 2005, leg. L. Deharveng & A. Bedos ( MNHN Ps116-01; collectors’ number KAM05-21) . Paratype protonymph (MNHN Ps116-02), collected with holotype.

DNA sequences. Partial sequences, obtained by non-destructive extraction from the palp of the paratype protonymph (voucher no. MNHN-JAD72), were deposited in GenBank for 18S RNA (accession no. JN018313.1) and 28S RNA (accession no. JN018410.1) by Arabi et al. (2012).

Description of male (limited to characters showing differences from C. deharvengi n. sp.). Tergal and sternal chaetotaxy not determined due to accumulation of exocuticle and debris, but where visible numbers of setae similar to those seen in C. deharvengi n. sp. Coxa I with 1 primary and 10–12 secondary spines around pit ( Figs 52, 55 ). Coxal setae ( Fig. 52 ): P 3 on manducatory process + 32 (total 35), I 8, II 9 (1 lateral), III 7 (1 lateral), 10 (1 lateral). Anterior genital sternite ( Fig. 52 ) with 12 setae, posterior genital sternite ( Fig. 52 ) with 14 setae (2+10+2). Male genitalia ( Fig. 58 ) very similar to those of C. deharvengi n. sp., but comparison of dorsal apodeme, lateral rods and atrial plate hampered by differences in orientation in the specimens examined (this depending on the degree to which the genital plates are open or closed); lateral sacs longer and thinner than those of C. deharvengi n. sp.; lateral pockets of atrial plate slightly longer than those of C. deharvengi n. sp.; posterior plate with 1 pair of modified basal setae, which seems to be more rounded at the tip than those of C. deharvengi n. sp., and 2 small, simple setae on each side.

Chelicera ( Figs 60–64 ) with 6‒7 small setae on palm, in addition to the 5 large setae. Galeal seta (gs) 0.85 from base, extending well beyond tip of spinneret (by nearly half length of hair). Spinneret ( Figs 61‒62 ) slightly thicker than in C. deharvengi n. sp., but still tubular (i.e. not blade-shaped), length 16 µm. Serrula exterior with 19–20 blades, plus small distally-directed apical process. Serrula interior with 17 internal ducts; apically with a distallydirected process, followed by two rows of three, low, rounded mounds; basal blades forming a velum. Rallum with 1 (right chelicera) or 2 (left chelicera; Fig. 63 ) blades, length 23 µm.

Palp as illustrated ( Figs 65–69 ). Fixed chelal finger with 12 chemosensory setae in antiaxial row. Movable finger with 14–16 long (22–24 µm), spatulate, chemosensory setae in pit ( Fig. 67 ). Trichobothria ( Figs 66, 68 ) eb and esb separated by 1.2–1.8 bothridial diameters (absolute distance 17–22 µm); sb slightly proximad of posterior edge of pit. Fixed finger with 30 teeth: apodens plus 22 marginal, 6 paraxial and basal tuberculate tooth. Movable finger with 28 teeth: apodens plus 21 marginal, 7 paraxial and basal tuberculate tooth.

Legs as illustrated ( Figs 70‒71 ).

Measurements (in mm, standard ratios in parentheses). Body (contracted) 1.82×1.25 (1.5). Carapace 0.659×0.47 (1.4). Chelicera 0.234×0.141 (1.7), palm 0.159 (1.1), movable finger 0.094. Palp femur 0.573×0.298 (1.8), patella 0.453×0.178 (2.5), chela 0.665×0.138 (4.8), palm 0.162 (1.2), movable finger 0.474 (2.9). Leg I femur 0.256×0.079 (3.3), patella 0.214×0.090 (2.4), tibia 0.212×0.062 (3.4), tarsus 0.304×0.051 (5.9). Leg IV trochanter 0.289×0.140 (2.1), femur 0.246×0.087 (2.8), patella 0.298×0.110 (2.7), tibia 0.426×0.063 (6.8), tarsus 0.418×0.052 (8.1).

Description of protonymph. Sclerotized parts pale straw-yellow, except tips of cheliceral fingers and teeth of chela, which are reddish-brown. Carapace ( Fig. 72 ) distinctly broadened posteriorly; less elongate than in adult; anteromedian projections small, anterolateral corners of carapace more rounded than in adult; two pairs of lyrifissures; two pairs of eyes with reflective tapeta, anterior pair sessile, posterior pair weakly raised, both pairs less prominent than in adult. Tergite I ( Fig. 72 ) with same general form as in adult, but presence or absence of separate lateral plate could not be determined due to weak sclerotization; tergites II–VIII divided (II and VIII weakly so); setae difficult to count, but most half-tergites with about 6 setae; denticulation present on tergites VIII– IX. Pleural membranes with two folds, as in adult, lyrifissures (orientated dorsoventrally) on dorsal fold; only 1 gland pore seen (anteriorly on dorsal fold), but others might be present; no setae observed; plates absent.

Palp coxa not as elongate as in adult, median maxillary lyrifissure present, with same form and position as that of adult; no lyrifissure distad of foramen. Coxa I with 1 primary and 9–10 secondary spines flanking pit ( Fig. 73 ); no pores in pit. Coxae III reduced in size, reaching closer to midline than in adult, overlapped by coxae II. Palp coxa with 12 setae (including 3 on manducatory process), leg coxae each with 3 setae. Sternites IV–X divided, setae 0: 2: 2+2: 3+3: 3+3: 4+4: 4+4: 4+4: 4+4: 4 (2 flanking anal tubercle): 2 (slightly closer together than those of tergite XI); denticulate granulation on IX–XI.

Chelicera ( Figs 74‒75 ) with distinction between smooth basal part and distal reticulate part of palm less well marked than in adult; three large (probably ls, sb and es) and four small setae on palm; movable finger without seta; rallum of 2 blades ( Fig. 75 ), as in adult; spinneret ( Fig. 74 ) simple, much longer (30 µm) than in adult, recurved apically. Serrula exterior with 10 blades plus apical process. Serrula interior with 10 ducts.

Palp ( Figs 76‒84 ) similar to that of adult, trochanter with well developed horn, femur with moderate anterobasal projection. Chela with three trichobothria on fixed finger and one on movable finger. Trichobothrium x 1 inserted dorsally in shallow depression, hair straight and directed backwards, length 44 µm; trichobothrium t distinctly crooked ( Fig. 83 ); hairs of other trichobothria (ist and it) lost or broken. Fixed finger with 21 teeth: apodens plus 14 marginal (irregular distally), 5 paraxial and basal tuberculate tooth. Movable finger with 21 teeth: apodens plus 15 marginal, 4 paraxial and basal tuberculate tooth. Tuberculate tooth of fixed finger bearing seta at base. Fixed finger with 3 lyrifissures: one on each side at base and 1 dorsal, just in front of trichobothrium it. Movable finger with 1 ventral lyrifissure, situated between t and pit; a single spot sensillum situated immediately behind lyrifissure ( Fig. 80 ). Movable finger with 5 clavate chemosensory setae in a pit that is shallower than that of adult ( Figs 79‒80 ). Proximal sensillum p 1 ( Fig. 84 ) situated about a third from base of movable finger ( Fig. 83 ); p 2 absent.

Legs ( Figs 85–87 ) similar to those of adult (apart from usual differences), except that the trochanter of leg IV is relatively smaller and all femora lack the dorsal lyrifissure and its depression; femur of leg IV with large dorsoparaxial lyrifissure at base ( Fig. 85 ) (as in adult).

Measurements (in mm, standard ratios in parentheses). Body 0.85×0.54 (1.6). Carapace 0.309×0.315 (0.98). Chelicera 0.129×0.082 (1.6), palm 0.092 (1.1), movable finger 0.062 (0.7×palm), spinneret 0.030 (0.5×movable finger). Palp femur 0.249×0.168 (1.5), patella 0.197×0.101 (1.9), chela 0.364×0.088 (4.1), palm 0.090 (1.0), movable finger 0.278 (3.1). Leg I trochanter 0.095×0.064 (1.5), femur 0.118×0.045 (2.6), patella 0.093×0.052 (1.8), tibia 0.093×0.048 (2.0), tarsus 0.173×0.041 (4.2). Leg IV trochanter 0.128×0.069 (1.8), femur 0.095×0.051 (1.9), patella 0.136×0.057 (2.4), tibia 0.166×0.045 (3.7), tarsus 0.230×0.042 (4.5).

Remarks. An attempt by Anne Bedos and the author to collect more material of C. bedosae n. sp. at the type locality in June 2008 was thwarted by dense brush outside the cave, which had grown since the previous visit in 2005, due to the cessation of grazing activity at the site. Berlese extractions of litter and soil samples taken just outside the cave in 2005 and nearby in 2008 did not produce any feaellids.

Although C. bedosae n. sp. and C. deharvengi n. sp. are very similar and known from only a few specimens, they appear to be isolated geographically, occurring in disjunct limestone hills about 60 km apart. Feaellidae appear to have very poor powers of dispersal and show high levels of endemism, so it seems reasonable to infer that two closely related species are involved, rather than a single variable or clinal species.

Figures

FIGURES 48 ‒ 49. Cybella bedosae n. sp. 48, habitus of male, dorsal view; 49, type locality, Kien Krol, Cambodia (photograph taken 23 June 2008); cave (not visible) is at base of hill.

FIGURES 50 – 59. Cybella bedosae n. sp., male. 50, anterior part of carapace, dorsal view (setae omitted); 51, tapeta of right eyes, ventral (internal) view; 52, leg coxae and median parts of sternites II ‒ III, ventral view; 53, intercoxal canal between posterior parts of palp coxae (membrane torn distally); 54, manducatory process of right palp coxa, ventral view (lyrifissure abnormally doubled); 55, primary spine and adjacent secondary spines of right coxa I; 56, left spiracle and adjacent apodeme of segment III, ventral view; 57, membranous part of intercoxal canal between coxa I and palp coxae (latter removed), ventral view; 58, genitalia, ventral view (right lgs omitted; part of anterior wall of genital atrium removed on left of drawing); 59, tergite (upper) and sternite (lower) of segment XII, ventral view. Abbreviations: ap, apodeme; da, dorsal apodeme; ejca, ejaculatory canal atrium; gp, gland pore; ic, intercoxal canal; inv, invagination at side of atrial plate; lgs, lateral genital sac; ly, lyrifissure; mgs, median genital sac; pcs, primary coxal spine; scs, secondary coxal spine; sp, spiracle; sps, spatulate seta; sr, sclerotized ring; tp, posteromedian tecta of palp coxae; tr, trachea; w, wall of coxa in cross-section. Scale lines 0.1 mm (Figs 50, 52), 0.05 (Figs 51, 53 ‒ 59).

FIGURES 60 – 69. Cybella bedosae n. sp., male. 60, left chelicera, antiaxial view; 61, distal end of movable finger of left chelicera, antiaxial view; 62, spinneret of left chelicera, ventral view; 63, rallum of left chelicera, antiaxial view; 64, left chelicera, dorsal view; 65, left palp, minus chela, dorsal view; 66, left chela, dorsal view; 67, chemosensory setae of movable finger of left chela, antiaxial view; 68, left chela, antiaxial view; 69, distal sensillum of movable finger Abbreviations: dx, duplex trichobothria, pc, coupled sensilla; pr, distal process of serrula exterior; s. ext, serrula exterior; s. int, serrula interior; r, rallum. Other abbreviations (eb, esb, est, et, ib, isb, ist, it, b, sb, st, t) are standard designations of trichobothria. Scale lines 0.2 mm (Figs 65 ‒ 66), 0.1 mm (Figs 60, 64, 68), 0.05 mm (Figs 61 ‒ 63, 67), 0.01 (Fig. 69) (figures 61 ‒ 63 share same scale line).

FIGURES 70 – 71. Cybella bedosae n. sp., male, legs. 70, right leg IV, antiaxial view; 71, right leg I, antiaxial view. Scale line 0.2 mm.

FIGURES 72 – 73. Cybella bedosae n. sp., protonymph. 72, carapace and anterior segments (I – III) of opisthosoma, dorsal view, reticulation of tergite I only partially drawn; 73, leg coxae, ventral view. Abbreviation: pcs, primary coxal spine. Scale lines 0.1 mm.

FIGURES 74 – 87. Cybella bedosae n. sp., protonymph, appendages. 74, right chelicera, antiaxial view; 75, rallum of right chelicera, paraxial view; 76, chela of right palp, dorsal view; 77, right palp, minus chela, dorsal view; 78, tip of fixed finger, dorsal view, setae omitted; 79, chemosensory setae of movable finger of right chela, ventral view; 80, chemosensory setae of movable finger of right chela, antiaxial view; 81, tip of fixed finger of right chela, paraxial view, setae omitted; 82, tip of movable finger of right chela, paraxial view, setae omitted; 83, right chela, antiaxial view; 84, proximal sensillum (p 1) of movable chelal finger, antiaxial view; 85, femur of right leg I, paraxial view, showing paraxial lyrifissure; 86, right leg I, antiaxial view (scaly ornamentation only partly indicated on femur, omitted on other segments); 87, right leg IV, antiaxial view. Abbreviations: cs, chemosensory seta; ly, lyrifissure. Other abbreviations are notations of cheliceral setae and chelal trichobothria. Scale lines 0.1 mm (Figs 76 ‒ 77, 83, 86 ‒ 87), 0.05 mm (Figs 74 ‒ 75, 78 ‒ 82, 85; Figs 75 and 78 ‒ 82 share same scale line), 0.01 mm (Fig. 84).