Gymnobisium prionotogladiatum, Neethling & Neethling, 2023

Neethling, J. A. & Neethling, C., 2023, A systematic revision of the South African Gymnobisiidae (Pseudoscorpiones: Neobisioidea), Zootaxa 5256 (6), pp. 501-543 : 529-533

Gymnobisium prionotogladiatum sp. nov.

Figs 21–23

Holotype: ♀, SOUTH AFRICA, Eastern Cape, Fort Beaufort, Fort Fordyce Nature Reserve, 32°41′S, 26°30′E, 1088m a.s.l., Afromontane forest , Leaf litter sifting, leg. J.A. Neethling, 11.X.2015 ( NMBAP 00343 ).

Paratypes: 2♀, 2♂, Same data as holotype ( NMBAP 00344 ) .

Etymology. The species name is a compound of the ancient Greek word prionotós, meaning jagged or serrate, and gladiatum, derived from the Latin word gladius meaning sword. The name refers to the multi-toothed structure found at the tip of the fixed chelal finger, which in this species contains a row of six small and highly sclerotized teeth, thus giving it the appearance of a serrated blade.

Diagnosis. Moderately sized species (chela length ♀ 1.56–1.61 mm, ♂ 1.52 –1.56 mm), with chelae more bulbous in females than in males (chela ratio ♀ 3.28–3.32 versus ♂ 3.80 –3.90 times longer than broad); fixed finger multi-toothed structure with eight strongly sclerotized teeth; cheliceral hand with five setae; galea with six to seven rami; rallum with eight to nine blades, sub-distal blade sometimes with an apical split. Differs from all congeners, except Gymnobisium octoflagellatum , by having eight teeth on the fixed finger multi-toothed structure; differs from G. octoflagellatum by having seven rami, while the latter has a minimum of eight.

Description

Carapace: Somewhat broader than long in both sexes, subquadrate, overall smooth and without furrow. Brown in females, darker in males. Two pairs of eyes located dorso-laterally at the front. Small seta located on the dorsoanterior margin of each of the posterior eyes. Carapace of both sexes with 20 setae, arranged 4: 4: 4: 2: 6.

Abdomen: Tergites and sternites smooth, undivided and uniseriate, brown in females and darker in males ( Fig. 21A, C ). In both sexes the lateral and posterior edges of tergites I–XI are distinctly lighter in colour, tergite XII uniformly brown. The tergal setae are located on the posterior edge of each tergite, within the lighter coloured band. Sternites I–II tan in females, with sternites III–XI light brown, becoming slightly darker towards the posterior edge of the abdomen. Male sternites I–II tan; III–IX light brown; X–II dark brown ( Fig. 21B, D ). Sternites I and II are fused and hardly distinguishable. Female operculum with nine setae, loosely grouped in the centre along the fuse line of sternites I and II. Males with 16 setae at the operculum cluster, five located along the posterior margin of sternite II at the genital opening, 11 additional setae located anteriorly next to these, loosely grouped in the centre of sternite II. Male sternite III with nine setae located on the anterior margin of the sternite, at the genital opening. Pleural membrane cream to light yellow in colour, faintly papillate.

Tergal chaetotaxy: 6(6): 10(8): 9(8): 11(9): 12(10): 12(11): 12(11): 12(10): 11(9): 9(9): 12(11): 2(2).

Sternal chaetotaxy: 9(16):?(?): 24(18): 18(16): 15(17): 13(15): 13(14): 14(15): 14(11): 11(9): 12(11): 2(2).

Pedipalp: All segments smooth and bright orange-brown in colour in both sexes. Trochanter cone-shaped and rounded anteriorly, curved slightly posteriorly. Base narrow, widening distally. Setae present on the anterior surface. Femur very slender, 3.79–4.05 (♀) to 4.14–4.45 (♂) times longer than wide, somewhat constricted basally, widening just distal of base. Deep disto-prolateral excavation present. Setae absent from base, though distributed evenly over rest of surface. Patella constricted and slightly angled at base, widening markedly distal at around a third segment length, 2.68–2.73 (♀) to 3.00–3.26 (♂) times longer than wide. Several small lyriform fissures present on the dorsal surface, just distal of base. Two larger lyriform fissures present latero-dorsally from these, where the segment starts to widen. Deep disto-prolateral excavation present. Setae sparse at base, more numerous on wide part of patella ( Fig. 23B ).

Chela: In both sexes smooth and uniformly bright orange-brown, fingers may be slightly darker. Female hand larger and slightly more bulbous, strongly convex on the prolateral edge, slightly less so on the retrolateral edge ( Fig. 22A, B ). Male hand smaller, less convex prolaterally ( Fig. 22C, D ). Pedicel regular in both sexes, retrolateral condyle small but distinct and rounded. Fingers narrow, longer than hand (without pedicel) and curved slightly prolaterally. Fixed and movable chelal fingers with eight and four trichobothria respectively ( Fig. 23A ).

Terminal multi-toothed structure extends well beyond venom tooth of movable finger in both sexes, curving downward. Female structure slightly more curved than male ( Fig. 23E ). In both sexes the structure consists of a large terminal tooth preceded by a row of six smaller, highly sclerotized teeth that remain constant in size. This row is situated slightly prolaterally behind the terminal tooth. Located retrolaterally at the base of the smaller teeth is another larger tooth.A single accessory tooth may also be present in some males, located above the six smaller teeth, and just distal of the basal large tooth ( Fig. 23F ). Both fingers with rounded, juxtadentate teeth situated on flexible lamellae. Lamella on female fixed finger originating roughly one quarter finger length from base, on movable finger at mid finger length. Lamella on male fixed finger originating roughly one third finger length from base, on movable originating just basal of finger midpoint. Female fixed finger with 57–60 lightly sclerotized, juxtadentate teeth, 11– 13 proximal to lamella base, together with eight strongly sclerotized teeth on distal structure. Male fixed finger with 56–58 lightly sclerotized, juxtadentate teeth, 12–14 proximal to lamella base, together with eight strongly sclerotized teeth on distal structure. Female movable finger with 56–58 lightly sclerotized, juxtadentate teeth, 22–23 proximal to lamella base, 33–34 on lamella, and one small, lightly sclerotized tooth at the posterior base of the venom tooth. Male movable finger with 54–56 lightly sclerotized, juxtadentate teeth, 18–19 proximal to lamella base, 35–36 on lamella, and one small, lightly sclerotized tooth at the posterior base of the venom tooth. Two thickened, spine-like setae present on distal end of movable finger in both sexes.

Chelicera: Hand with five long and acuminate setae, es shorter ( Fig. 23C ). Female fixed finger with 12 teeth, male with 11. Female moveable finger with nine teeth, male with ten. Galea of females divided into six rami ( Fig. 23D ), seven in males ( Fig. 23G ). Female rallum with nine long, acuminate blades, subdistal blade with a small, finger-like, protuberance at terminal ( Fig. 23H ). Male rallum with eight long, acuminate blades ( Fig. 23I ). Lamina exterior absent in both sexes.

Coxae and legs: Pedipalpal coxae same colour, or slightly lighter than rest of pedipalps. Coxae I–IV tan. Legs I–IV light brown to tan in colour. All legs diplotarsate with subterminal tarsal setae dentate distally; claws simple; arolium shorter than claws.

Measurements (mm): Body length ♀ 1.86– 2.26 ♂ 1.88–1.98; Carapace ♀ 0.66–0.68 x 0.77–0.80 (0.85–0.86) ♂ 0.59 –0.62 x 0.62–0.66 (0.94–0.95); Chelicera ♀ 0.54–0.56 x 0.26–0.28 (2.00–2.08) ♂ 0.46 –0.50 x 0.25–0.26 (1.84–1.92), movable finger length ♀ 0.33– 0.34 ♂ 0.29–0.30; Pedipalps: femur ♀ 0.89–0.91 x 0.22–0.24 (3.79– 4.05) ♂ 0.89 –0.91 x 0.20–0.22 (4.14–4.45), patella ♀ 0.71–0.75 x 0.26–0.28 (2.68–2.73) ♂ 0.75 –0.78 x 0.23–0.26 (3.00–3.26), chela ♀ 1.56–1.61 x 0.47–0.49 (3.28–3.32) ♂ 1.52 –1.56 x 0.39–0.41 (3.80–3.90), hand ♀ 0.77–0.82 x 0.47–0.49 (1.63–1.67) ♂ 0.76 –0.79 x 0.39–0.41 (1.93–1.95), movable finger length ♀ 0.74– 0.76 ♂ 0.71–0.75; Leg I: femur ♀ 0.41–0.43 x 0.11–0.12 (3.58–3.73) ♂ 0.39 –0.41 x 0.11–0.12 (3.42–3.54), patella ♀ 0.31–0.32 x 0.11 (2.82–2.91) ♂ 0.28 –0.29 x 0.11 (2.54–2.64), tibia ♀ 0.34–0.36 x 0.09–0.10 (3.60–3.78) ♂ 0.33 –0.34 x 0.07–0.08 (4.71–4.25), metatarsus ♀ 0.19–0.20 x 0.08 (2.37–2.50) ♂ 0.17 –0.18 x 0.06–0.07 (2.57–2.83), tarsus ♀ 0.22–0.23 x 0.07 (3.14–3.28) ♂ 0.21 –0.22 x 0.06 (3.50–3.67); Leg IV femoropatella ♀ 0.81–0.86 x 0.20–0.21 (4.05–4.09) ♂ 0.80 –0.83 x 0.19–0.21 (3.95–4.21), tibia ♀ 0.67–0.71 x 0.12 (5.58–5.92) ♂ 0.65 –0.67 x 0.13 (5.00–5.15), metatarsus ♀ 0.29–0.31 x 0.08 (3.62–3.87) ♂ 0.27 –0.29 x 0.08 (3.37–3.62), tarsus ♀ 0.35–0.37 x 0.08 (4.37–4.62) ♂ 0.34 –0.35 x 0.08 (4.25–4.37).

Remarks. Although geographically close to both Gymnobisium cuneatum sp. nov. and G. hogsbackense sp. nov., the latter are isolated in the indigenous Afromontane forest patches of their type locality, while G. prionotogladiatum sp. nov. occurs over a larger geographic area in both indigenous Afromontane forest patches as well as coastal bushland. The first specimens of this species were collected in 1945, but were misidentified as G. quadrispinosum .

Additional material examined. SOUTH AFRICA: Eastern Cape: 5 Tritonymphs, Fort Beaufort, Fort Fordyce Nature Reserve , 32°41′S, 26°30′E, 1092m a.s.l., Afromontane forest , Leaf litter sifting, leg. J.A. Neethling & C. Neethling, 30.XI.2012 ( NMBAP 00325 ) ; 3♀, 1♂, 1 Tritonymph, Same location, 32°41′S, 26°30′E, 1090m a.s.l., Afromontane forest , Vegetation beating, leg. C.R. Haddad, 30.XI.2013 ( NMBAP 00324 ) ; 2♀, 10♂, 49 Tritonymphs, Same location, 32°41′S, 26°30′E, 1092m a.s.l., Afromontane forest , Leaf litter sifting, leg. J.A. Neethling, 11.X.2015 ( NMBAP 00326 ) ; 7 Tritonymphs, Fort Beaufort, Katberg , 32°28′S, 26°40′E, 1244m a.s.l., Afromontane forest , Leaf litter sifting, leg. J.A. Neethling & C. Neethling, 1.XII.2012 ( NMBAP 00333 ) ; 1♀, Same location [32°28′S, 26°40′E], Afromontane forest , Leaf litter sifting, leg. N. Leleup, I.1961 ( RMCA 127851 , previously ZA 64) ; 2♀, 1 Tritonymph, Port St. Johns [31°36′S, 29°32′E], Coastal bush, leg. R.F. Lawrence, VII.1945 ( NMSA 680 ) .

Figures

FIGURE 21. Digital microscope photographs of Gymnobisium prionotogladiatum sp. nov., Female (A, B) and Male (C, D). A, C. Dorsal view; B, D. Ventral view. Scale bar: 1.00 mm.

FIGURE 22. Digital microscope photographs of Gymnobisium prionotogladiatum sp. nov. right chela: Female (A, B) and Male (C, D). A, C. Retrolateral view; B, D. Dorsal view. Scale bar: 1.00 mm.

FIGURE 23. Gymnobisium prionotogladiatum sp. nov. A. Female right chela, retrolateral view; B. Female right pedipalp, dorsal view; C. Female left chelicera, dorsal view; D. Female galea; E. Female chelal fingers, anterior retrolateral view; F. Male fixed chelal finger, anterior retrolateral view; G. Male galea; H. Female rallum; I. Male rallum. Scale bars: A, B: 0.50 mm; C, E, F: 0.20 mm; D, G–I: 0.10 mm.