Neobisium (Neobisium) vilcekii Krumpal , 1983

Kolesnikov, Vasiliy B., Christophoryova, Jana, Przhiboro, Andrey A. & Turbanov, Ilya S., 2022, The pseudoscorpions of the Caucasian Sphagnum bogs: part I. Description of Neobisium (Neobisium) adjaricum sp. nov. and redescription of the holotype of N. (N.) vilcekii Krumpal, 1983 (Arachnida, Pseudoscorpiones, Neobisiidae), ZooKeys 1100, pp. 165-190 : 165

Neobisium (Neobisium) vilcekii Krumpal, 1983

Figs 3B , 7 , 8 , 9

Material examined.

Holotype ♂ (SNM 28SR), Russia, North Ossetia-Alania, Prigorodnyi Distr., near Karmadon , 1.VI.1976, Mikuláš J. Lisický leg.

Diagnosis.

Carapace with short and apically rounded epistome; two pair of eyes present, lenses of posterior eyes with low convexity; movable cheliceral finger with large median tooth; pedipalpal segments smooth, covered with fine reticulate ornament; notch on median side of pedipalpal patella not extending from distal third of patellar club length; movable finger longer than hand+, but almost equal to femur in length; trichobothrium ist situated distal to middle of fixed chelal finger; distal half of fixed chelal finger with teeth almost equal in size and shape; anterolateral process of coxa of leg I pointed and relatively short, with mediolateral process slightly prominent, denticulate; sternite II with 15 setae; pedipalpal femur 4.41 × as long as broad (1.41/0.32), chelal hand+ 1.89 × as long as broad (1.19/0.63); movable chelal finger length 1.40.

Redescription.

♂. Coloration: carapace reddish brown, opisthosoma and legs paler.

Carapace (Figs 7A , 9A-C ): without transverse furrows, covered with reticulate ornament (Fig. 9A ); 0.71 × as long as broad, with two pairs of corneate eyes (Figs 7A , 9B ), anterior eyes slightly larger than posterior ones (0.11 vs. 0.09); distance between anterior margin of anterior eye and anterior margin of carapace 0.09, diameter of anterior eye 0.07, diameter of posterior eye 0.08, distance between eyes 0.02; carapace with 24 setae, anterior margin with 6 macrosetae, posterior margin with 7 setae; chaetotaxy: 6:7:4:7; all anterior setae almost equal in length (Fig. 7A ); epistome short and apically rounded, 0.03/0.05 (Figs 7A , 9C ); glandular pores present (Fig. 7A ); anterolateral corners with two small protuberances; carapace with 6 microlyrifissures: one pair situated in ocular zone, close to anterior eyes, and two pairs located at posterior margin (Fig. 7A ).

Tergites undivided, posterior ones damaged; all setae acuminate; chaetotaxy of tergites I-IX: 5:6:11:12:11:12:12:13:12.

Sternites undivided, posterior ones damaged; all setae acuminate; anterior operculum with 15 setae and one lyrifissure, posterior operculum with 38 setae, of which 19 located close to genital aperture and two lyrifissures (Fig. 8A ); chaetotaxy of sternites II-IX: 15:(5)38(6):(4)16(4):19:17:15:15:15.

Internal genitalia (Fig. 9D ) with moderately long lateral and median genital sacks, median sack wrinkled; genital opening with 8+7 internal setae.

Pleural membrane granulated (Fig. 9E ). Chelicera (Figs 7B, C , 9F ): 1.51 × as long as broad; hand with 7 acuminate setae and two lyrifissures (Fig. 7B ); galea knob-like, with poorly developed hyaline convexity; sub-galeal seta situated distal to middle (T = 0.11) of movable finger; small tooth (tis) under interior seta is present, blunt (Fig. 9F ); hand covered with faint reticulate pattern with pointed corners; fixed finger with 13 teeth reaching finger base, movable finger with 6 teeth reaching middle of finger, large median tooth present; serrula interior with 20 blades, serrula exterior with 27 blades; rallum (Fig. 7C ) with 8 blades, two distal ones denticulate, 6 posterior blades simple, smooth and acuminate, 3 proximal blades smallest.

Coxae (Figs 7D , 9G ): pedipalpal coxa excluding manducatory process with 10 setae, manducatory process with 5 acuminate setae; coxa I with short triangular, sclerotised, apically pointed anterolateral process (0.04/0.05) (Fig. 9G ), mediolateral process denticulate; coxal chaetotaxy of legs: 10-11:10-12:8-9:13, all setae acuminate; lyrifissures: two on each pedipalpal coxa, one on each coxa I-III of legs, not visible on pedal coxae IV; pedipalpal coxa with one maxillary lyrifissure.

Pedipalp (Figs 8B, C , 9H-K ): pedipalpal segments smooth (Fig. 9H ); all setae acuminate; trochanter with small dorsal tubercle and one lyrifissure (Fig. 8B ), 2.03 × as long as broad; femur with short pedicel, margins of femur without tubercles, 5 glandular pores present (Fig. 8B ), 4.41 × as long as broad; patella with short pedicel, 3 glandular pores present (Fig. 8B ), 2.67 × as long as broad, with 3 lyrifissures basally and 2 distally (Fig. 8B ); chela+ 3.76 × and chela- 3.57 × as long as broad; movable finger distinctly longer than hand+, 1.18 ×, but almost equal to femur in length, 0.99 ×; hand+ 1.89 × and hand- 1.68 × as long as broad, pedicel with faint reticulate pattern with pointed corners (Fig. 9I ); retrolateral surface of hand with one glandular pore located near trichobothrium eb (Fig. 8C ); fixed finger with one lyrifissure: fb located slightly proximal to trichobothrium ib (Fig. 9J ), fa and fd not visible; lyrifissures on movable finger not visible; two coupled sensilla pc situated between st and sb (Figs 8C , 9K ); fixed finger with 65 contiguous triangular teeth reaching level of trichobothrium ib, teeth almost equal in size; movable finger with 54 contiguous teeth not reaching level of trichobothrium b, teeth blunt and apically rounded; nodus ramosus of venom duct in fixed chelal finger short, situated very close to finger tip (Fig. 8C ).

Trichobothriotaxy (Fig. 8C ): fixed finger with 8 trichobothria, movable finger with 4 ones; fixed finger with close-set trichobothria esb and eb located slightly proximal to ib, with isb on retrolateral surface, ib closer to isb than to esb, ist distinctly closer to est than to isb, distance ist - est approximately the same as distance est - it, but less than twice as long as distance est - et in lateral view, trichobothrium ist situated distal to middle of finger, ist located distinctly proximal to t, et located proximal to it, at approximately the same distance between est and it (in lateral and dorsal views), ist situated distal to middle of finger; movable finger with trichobothrium st situated slightly closer to t than to sb, trichobothrium sb slightly closer to b than to st, distance b - sb almost equal to distance st - t.

Legs (Fig. 7E ): all claws of legs with small dorsal accessory tooth, arolia simple and shorter than claws. Leg I trochanter 1.42 ×, femur 5.79 ×, patella 4.07 ×, tibia 5.82 ×, metatarsus 3.80 × and tarsus 5.40 × as long as deep. Leg IV trochanter 2.11 ×, femoropatella 3.75 ×, tibia 6.33 ×, metatarsus 4.23 × and tarsus 6.82 × as long as deep; tibia IV with long tactile seta situated slightly proximal to middle (T = 0.21 in length, 0.52 from base), metatarsus IV with long tactile seta situated basally (visible only base of trichobothrium, 0.08 from base), tarsus IV with tactile seta situated approximately in middle of segment (T = 0.35, 0.37 from base); sub-terminal setae branched.

Measurements: body length 3.65; carapace 0.92/1.30; chelicera 0.59/0.39, movable finger of chelicera 0.42; pedipalp: trochanter 0.69/0.34, femur 1.41/0.32, patella 1.04/0.39, chela+ 2.37, chela- 2.25, hand+ 1.19/0.63, hand- 1.06, movable finger 1.40; leg I: trochanter 0.34/0.24, femur 0.81/0.14, patella 0.57/0.14, tibia 0.64/0.11, metatarsus 0.38/0.10, tarsus 0.54/0.10; leg IV: trochanter 0.57/0.27, femur+patella 1.35/0.36, tibia 1.14/0.18, metatarsus 0.55/0.13, tarsus 0.75/0.11.

Remarks.

The states of several characters reported here slightly differ from those in the original description of N. (N.) vilcekii ( Krumpál 1983), viz. the number of setae on the posterior carapace margin (7 vs. 8); number of setae on the tergites III (11 vs. 10), V (11 vs. 12) and VIII (13 vs. 12); number of setae on the sternites III [(5)38(6) vs. (6)37(6)], VI (17 vs. 16), VIII and IX (each with 15 vs. each with 14); number of internal setae in the genital opening (8 + 7 vs. 7 + 7); number of teeth on the fixed and movable cheliceral fingers (13 and 6 vs. 11 and 4); number of setae on the coxae II of legs (10-12 vs. 11-12) and pedal coxae III (8-9 vs. 9-11) and IV (13 vs. 12-13); body length (3.65 vs. 3.04); carapace (0.92/1.30 vs. 0.69/0.95); pedipalpal trochanter (0.69/0.34 vs. 0.60/0.32). The numbers of setae on two last tergites and sternites are missing in the present redescription because these segments were damaged on the slide mount, but the respective data are given in the original description (tergites X with 12, XI with 10 and sternites X with 16, XI with 12 setae; see Krumpál 1983). Several new characters were added in the present redescription, namely, the measurements and ratio of length to width of chelicera, measurements and ratio of length to depth of trochanters of leg I and leg IV, presence of glandular pores, number of lyrifissures on carapace, number of blades on serrula exterior and interior, presence of tooth tis on chelicera, number of lyrifissures on palps and coxae.

The holotype differs from the specimens described by Nassirkhani and Snegovaya (2021) in the following characters: the number of setae on the anterior carapace margin (6 vs. 4), number of setae on the sternites II (15 vs. 10-14) and III (38 vs. 39-47); number of setae around male genital aperture on the sternite III (19 vs. 21-27), number of internal setae in the genital opening (8 + 7 vs. 5-6+5-6), number of teeth on fixed and movable cheliceral fingers (13 and 6 vs. 15-18 and 10-12), chela+ (3.76 × vs. 4.00-4.33 ×) and chela- of the male (3.57 × vs. 3.84-4.12 ×); chelal hand+ (1.89 × vs. 1.98-2.15 ×) and hand- of the male (1.68 × vs. 1.73-1.89 ×), number of the pc sensilla (two, between st and sb, vs. one, proximal to sb), number of teeth on the movable chelal finger of male (54 vs. 56-62), and number of setae on the coxa IV (13 vs. 15-22). The states of most characters mentioned here are within the variability range of this species ( Krumpál 1983; Nassirkhani and Snegovaya 2021).

Distribution.

The species is known only from two localities in the Republic of North Ossetia-Alania (Russia) in the North Caucasus: the type locality near Karmadon (ca. 1500 m a.s.l.), and another locality in the valley of the Terek River in the environs of Mozdok (115 m a.s.l.) that was reported by Nassirkhani and Snegovaya (2021). The localities are situated at different altitudes, hence they should strongly differ from each other in the landscape and climatic conditions.

Habitats.

The habitat of N. (N.) vilcekii near Karmadon is unclear ( Krumpál 1983). It is questionable whether the species is confined to mire or wet habitats. The material from the environs of Mozdok that was used by Nassirkhani and Snegovaya (2021) for redescription was collected in a floodplain, in litter consisting of leaves of broad-leaved trees mixed with wood pieces. Hence, it is possible that N. (N.) vilcekii is a hygrophilous species.

Figures

Figure 3. A habitus of Neobisium (Neobisium) adjaricum sp. nov., holotype male, dorsal view B permanent slide mount with Neobisium (Neobisium) vilcekii Krumpal, 1983, holotype male. Scale bar: 1 mm.

Figure 7. Neobisium (Neobisium) vilcekii Krumpal, 1983, holotype male A carapace, dorsal view B right chelicera, dorsal view C rallum, ventral view D coxae of pedipalp and legs I-IV, ventral view E left leg IV, dorsal view. Abbreviation: dat - dorsal accessory tooth. Scale bars: 0.1 mm.

Figure 8. Neobisium (Neobisium) vilcekii Krumpal, 1983, holotype male A sternites II-III, ventral view B left pedipalp (without chela), dorsal view C left chela, lateral view. Abbreviations: trichobothria on fixed chelal finger: eb - exterior basal, esb - exterior sub-basal, est - exterior sub-terminal, et - exterior terminal, ib - interior basal, isb - interior sub-basal, ist - interior sub-terminal, it - interior terminal; trichobothria on movable chelal finger: b - basal, sb - sub-basal, st - sub-terminal, t - terminal; fb - lyrifissure, pc - coupled sensilla. Scale bars: 0.1 mm.

Figure 9. Neobisium (Neobisium) vilcekii Krumpal, 1983, holotype male, light microscope images A detail of ornamentation on carapace, dorsal view B left eyes, dorsal view C epistome, dorsal view D genitalia, ventral view E detail of pleural membrane, dorsal view F tooth close to seta it on chelicera, dorsal view G anterolateral processes on coxae of leg I, ventral view H detail of ornamentation on pedipalpal hand, dorsal view I detail of pattern on pedicel of pedipalpal hand, dorsal view J lyrifissure on fixed chelal finger, lateral view K coupled sensilla on movable fixed finger, lateral view. Abbreviations: trichobothria on fixed chelal finger: esb - exterior sub-basal, isb - interior sub-basal; trichobothria on movable chelal finger: sb - sub-basal; fb - lyrifissure, pc - coupled sensilla; tis - tooth close to seta is on chelicera. Scale bar: 0.1 mm.