Xevioso cepfi, Pett & Jocqué, 2020

Pett, Brogan L. & Jocqué, Rudy, 2020, Description of two new species of Xevioso (Araneae: Phyxelididae) from Southern Africa, with the northernmost localities for the genus, European Journal of Taxonomy 636, pp. 1-18 : 3-9

Xevioso cepfi sp. nov.

urn:lsid:zoobank.org:act:500CF91F-7D90-466F-88F3-1E48938DF676

Figs 1–3 , 4A, D , 5 , 8

Diagnosis

Males of X. cepfi sp. nov. can be recognized by the axel-shaped, dark dorsal asetose process of the palpal T, which is thin and transparent in X. jocquei , combined with the pronounced, blunt DP ( Figs 1C , 3 B–C, 4A) and the palpal bulb with sharp bifid tegular process on TA3 which is shorter and blunt in X. jocquei . Females are characterized by the double coil of the copulatory duct, the anterior median duct of the spermathecae being almost twice as large as the posterolateral duct, also the anterior median duct converging centrally and almost touching ( Fig. 5 B–C).

Etymology

Named after the Critical Ecosystem Partnership Fund (CEPF), funders of the Njesi BINCO expedition, during which this species was discovered.

Material examined

Holotype

MOZAMBIQUE • ♂; Niassa Region, Sanga Plateau ; 12°22.580 S, 35°20.013 E; 1724 m a.s.l.; 18 Nov. 2016; L. Geeraert and M. Jocqué leg.; forest; pitfall with fence; RMCA_ARA_245493 .

Paratypes

MOZAMBIQUE • 1 ♀; Niassa Region, Sanga Plateau ; 12°22.5802 S; 35°20.0132 E; 1724 m a.s.l.; 15 Nov. 2016; L. Geeraert and M. Jocqué leg.; forest; pitfall with fence; RMCA_ARA_246405 • 3 ♂♂; same collection data as for preceding; RMCA_ARA_245506 • 2 ♂♂; same collection data as for preceding; MHNM • 1 ♀; Niassa Region, Sanga Plateau ; 12°24.007′ S, 35°20.070′ E; 16 Nov. 2016; L. Geeraert and M. Jocqué leg.; montane forest; pitfall with fence; RMCA_ARA_245496 • 2 ♂♂; Niassa Region, Chitagal Plateau ; 12°35.4952 S, 35°15.1342 E, 1624 m a.s.l.; Nov. 2016; montane forest; pitfall for herpetology; L. Geeraert and M. Jocqué leg. RMCA_ARA_245487 .

Other material

MOZAMBIQUE • 2 ♂♂; Niassa Region, Sanga Plateau ; 12°24.0072 S, 35°20.0702 E; 16 Nov. 2016; montane forest; L. Geeraert and M. Jocqué leg.; pitfall for herpetology; RMCA_ARA_246548 • 2 ♂♂; Niassa Region, Sanga Plateau ; 12°22.5802 S, 35°20.0132 E; 1724 m a.s.l.; 14 Nov. 2016; forest; pitfall; L. Geeraert and M. Jocqué leg.; RMCA_ARA_246550 • 1 ♂; same collection data as for preceding; RMCA_ARA_246551 • 2 ♂♂; same collection data as for preceding; 18 Nov. 2016; RMCA_ARA_246552 • 2 ♂♂; same collection data as for preceding; RMCA_ARA_246553 • 1 ♂; Niassa Region, Chitagal Plateau ; 12°35.495′ S, 35°15.134′ E; 1624 m a.s.l.; 8 Nov. 2016; L. Geeraert and M. Jocqué leg.; montane forest; pitfall; RMCA_ARA_246554 • 1 ♂; same collection data as for preceding; RMCA_ARA_246549 • 1 ♂; same collection data as for preceding; 11 Nov. 2016; RMCA_ ARA_246555 • 1 ♂; Niassa Region, Njesi Plateau ; 12°49.5332, S, 35°11.1002 E; 24 Nov. 2016; L. Geeraert and M. Jocqué leg.; montane forest; pitfall with fence; RMCA_ARA_246556 .

Description

Male holotype

TOTAL LENGTH. 4.60. Carapace: length 2.15, width 1.68, height 1.63.

COLOUR ( Fig. 1 A–B). Carapace light yellowish-brown, lighter posteriorly, shading to dark brownishorange at pars cephalica, blackened around eyes and between AME. Co and Tr concolorous with posterior region of carapace, remainder of legs darkened to pale brownish-orange at tip of each metatarsus. Chelicerae darkest part of body, dark red-brown, with clypeus orange-brown. Sternum cream yellow. Dorsum of abdomen grey, venter pale grey, with some paler areas, pedicel concolorous with sternum.

CARAPACE. Margins weakly sinuate, with very sparse short setae. Carapace with highest point in cephalic area, 1.5 times higher than at fovea (1.63 vs 1.04).

EYES. ALE 0.11; AME 0.10; PLE 0.06; PME 0.06; ALE-AME 0.05; AME-AME 0.03; PME-PME 0.12.

CHELICERAE. Promargin with six teeth, three smallest distally and three larger proximally, with the median of the larger teeth being largest. Retromargin with four small and one large tooth.

ABDOMEN. With short black setae, denser laterally and longest at posterior apex. Venter with dispersed setae, longest at posterior apex.

LEGS. Formula 1423, F I thicker, weakly undulated. P with small but distinct retrolateral process/ protrusion. Mt I with very weak pl concavity ¾ towards apex (fig. 4D).

LEG MEASUREMENTS.

F P T Mt t Total

I 2.52 0.88 2.24 2.04 0.87 8.55

II 1.88 0.72 1.52 1.42 0.84 6.38

III 1.68 0.68 1.24 1.32 0.75 5.67

IV 2.16 0.64 2.08 1.81 0.80 7.49

SPINATION. Leg I: F = pl1, T = v3, Mt = v4; Leg II: F = pl1, T = pl1 v2, Mt = pl1 rl1 v3; Leg III: T = pl2 rl2 v2; Leg IV: T = pl1 d2 rl1 v3.

STERNUM ( Fig. 1A ). 1.2 long, 0.92 wide. Shield-shaped, with slightly sinuous lateral margins. Black setae longer at margins and without setae centrally. No precoxal sclerites.

PALP ( Figs 1 C–D, 2A–C, 3A–C, 4A). F with two short stout anterobasal thorns. T with strong, dark axle-shaped process and pronounced DP, delimiting concavity with narrow opening. Palpal bulb simple, not divided into basal and retrobasal lobes. Embolus broadest at base but tapered apically into slender corkscrew, with three coils. TA3 with two acutely pointed prongs, TA2 lobate with short, blunt tip. EBS tri-partite, EBA1 sub-quadrate with weak posterior point, EBA2 recurved and slender, EBA3 fine and serrated with apex curving dorsally. Conductor with rl transverse ridge, basocentral lobe distad of embolus, and lateral and apical fringe.

Female paratype

TOTAL LENGTH. 4.45. Carapace length 2.04. Carapace width 1.45. Carapace height 1.12.

COLOUR. Carapace uniform, creamy yellow-brown. Clypeus from AME’s darker, orange-brown, thin line around margin of clypeus black. Chelicerae substantially darker, a deep reddish brown. Legs concolorous with carapace, except leg I: darkening at Mt a deep orange. Abdomen grey with short black setae, venter paler grey, creamy at anterior margin with pedicel concolorous with carapace base.

CARAPACE. Margins very weakly sinuate, if at all. Sparse black setae reach highest abundance medially, anterior of the fovea.

EYES. ALE 0.08; AME 0.09; PLE 0.07; PME 0.06; ALE-AME 0.06; AME-AME 0.04; PME-PME 0.12

CHELICERAE. Promargin with four teeth, retromargin with six small teeth

ABDOMEN. Venter light grey to cream at anterior, with short black setae uniform throughout, getting only marginally longer at the posterior end.

LEGS. Formula 143? (missing leg II). F I undulates weakly ¾ of length toward apex. As in males, distinct but small rl process/ protrusion at pa. Females lack pl concavity at the mt present in males.

LEG MEASUREMENTS.

F P T Mt t Total

I 1.73 0.72 1.60 1.34 1.01 6.40

II – – – –– –

III 1.40 0.57 0.93 0.91 0.63 4.44

IV 1.67 0.73 1.58 1.48 0.83 6.29

SPINATION. Leg I: F = pl1, T = v1, Mt = v3; Leg III: F = pl2 rl1 v1, Mt = 3disp, 4dw; Leg IV: T= rl1 v1, Mt = 4disp, 4dw.

STERNUM. Roughly shield-shaped, straight at anterior margin. Black setae at margins but without setae centrally. 1.10 long and 0.94 wide.

EPIGYNE ( Fig. 5 A–D). Posterior median lobe of epigyne twice as wide as long, widest at lateral midpoint. Vulva with spermathecae cylindrical, with external spiral of three turns. Anterior median duct of spermathecae converge slightly at anterior apex, towards touching from lateral. Dorsal posterior chambers face laterally.

Figures

Fig. 1. Xevioso cepfi sp. nov., holotype, ♂ (RMCA_ARA_245493). A. Habitus, ventral view. B. Habitus, dorsal view. C. Palp, retrolateral view. D. Palp, ventral view. Scale bars: A–B = 1 mm; C–D = 200 μm.

Fig. 2. Xevioso cepfi sp. nov., ♂, paratype (RMCA_ARA_245487). A. Palp, ventral view. B. Palp, as preceding, detail. C. Palp, retrolateral view. Abbreviations: EBS = basal embolic sclerite; E = embolus; TA2, TA3 = tegular apophyses 2 and 3. Scale bars = 100 μm.

Fig. 3. Xevioso cepfi sp. nov., holotype, ♂ (RMCA_ARA_245493). A. Palp, ventral view. B. Palp, retrolateral view. C. Palpal tibia, dorsal view. Abbreviations: EBS = basal embolic sclerite; E = embolus; CL = lateral ridge of conductor; TA2, TA3, TA4 = tegular apophyses 2, 3 and 4. Scale bars = 200 μm.

Fig. 4. A, D. Xevioso cepfi sp. nov., holotype, ♂ (RMCA_ARA_245493). B, E. Xevioso jocquei Griswold, 1990, holotype, ♂ (RMCA_ARA_156494). C. Xevioso megcummingae sp. nov., holotype, ♂ (RMCA_ ARA_236654). A–C. Palpal tibia, dorsal view. D–E. Mt I, dorsal view. Scale bars: A = 200 μm; B–C = 100 μm; D–E = 0.5 mm.

Fig. 5. Xevioso cepfi sp. nov., ♀, paratype (RMCA_ARA_245496), epigyne. A–B. Ventral view. C. Cleared, ventral view. D. Cleared, dorsal view. Abbreviations: CO = copulatory opening; PC = posterior chamber; PML = posterior median lobe. Scale bars = 200 μm.

Fig. 8. Distribution. Xevioso cepfi sp. nov. (▲), Xevioso jocquei Griswold, 1990 (■), Xevioso megcummingae sp. nov. (●).