Lagynochthonius maanensis Hou, Feng & Zhang 2023
Creators: name: SUN, JIANZHOU
name: GUO, XIANGBO
name: ZHANG, FENG
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Pseudoscorpiones
Chthoniidae
Lagynochthonius
Lagynochthonius maanensis

description: Lagynochthonius maanensis Hou, Feng & Zhang, 2023
Chinese name. Ḷḋȗ伪Dz
Figs 40–44
Lagynochthonius maanensis Hou, Feng & Zhang, 2023a: 31–35, figs 23–26.
Material examined. ♀ (Ps.- MHBU-GZZA-20-18-01) (holotype), paratype: 1 ♀ (Ps.- MSWU-GZZA-20-18-02) (paratype): China, Guizhou Province, Zheng’an County, Hexi Town, Maan Village, Pianxiao Cave, under stones in the deep zone [28.410517°N, 107.442178°E], 932 m a.s.l., 25 August 2020, Zegang Feng, Hongru Xu & Yanmeng Hou leg; 2 ♂ (Ps.- MHBU-GZ2024012701–02), 1 ♀ (Ps.- MHBU-GZ2024012703): China, Guizhou Province, Zunyi City, Zhengan County, Hexi Town, MaanVillage, Pianxiao Cave [28.40952199°N, 107.45909766°E], 680 m a.s.l., 27 January 2024, Jiaqi Zhao, Yitin Xu & Jianzhou Sun leg.
Revised diagnosis. (♂ ♀). Moderately sized hypogean species; carapace without eyes or eyespots, anterior margin smooth and epistome obtuse and small, round; tergites Ⅰ–ⅠⅠ each with two setae, tergites ⅠⅠⅠ–ⅠV each with four setae. Pedipalps slender, chela 5.00–5.94 (♂), 5.84–5.94 (♀) times as long as broad; femur 6.40–6.70 (♂), 5.43–6.55 (♀) times as long as broad; chelal fingers without intercalary teeth and a modified accessory tooth (td) on prolateral-retrolateral face; chemosensory setae (sc) present on dorsum of chelal hand.
Description. Adult males (Figs 40A, 41A–F, 42, 43).
Color generally pale yellow, chelicerae, carapace, pedipalps and tergites slightly darker black, soft parts pale.
Cephalothorax (Figs 41D, 42A): carapace nearly subquadrate, 0.95–0.98 times as long as broad, weakly constricted basally; posterior region with squamous sculpturing laterally, other area smooth, without furrows; anterior margin smooth, without serrations; epistome obtuse and small, round, without eyes or eyespots; with 18 setae arranged s4s: 4: 4: 2: 2, most setae heavy, long and gently curved, anterolateral setae much shorter than others; with three pairs of lyrifissures, first and second pair situated middle and flank to the setae of ocular row, third pair situated lateral to the sole pair of setae of posterior row. Manducatory process with two acuminate distal setae, anterior seta more than 1/2 length of medial seta; apex of coxa I with a rounded anteromedial process; coxae II with 7–9 terminally indented coxal spines on each side, set as an oblique and arc row, central spines slightly longer than the others (Fig. 42D); intercoxal tubercle absent; chaetotaxy of coxae: P 3, I 3, II 4, III 5, IV 5.
Chelicera (Figs 41C, 42B):almost as long as carapace, 1.90 times as long as broad; five setae and two lyrifissures (exterior condylar lyrifissure and exterior lyrifissure) present on hand, all setae acuminate, ventrobasal setae shorter than others; movable finger with one medial seta. Cheliceral hand with moderate wrinkle on both ventral and dorsal sides. Both fingers well provided with teeth, fixed finger with 8–9 teeth, distal one largest; movable finger with 11 retrorse contiguous small teeth; galea completely vestigial (Fig. 42B). Serrula exterior with 19–20 and serrula interior with 11 blades. Rallum with 7–8 blades, the distal one longest and recumbent basally, with fine barbules and slightly set apart from the other blades, latter tightly grouped and with long pinnae, some of which are subdivided (Fig. 42C).
Pedipalp (Figs 41A–B, 41E, 42E, 43A–B): trochanter 1.73–2.00, femur 6.40–6.70, patella 2.00–2.08, chela 5.00–5.94, hand 1.89–2.25 times as long as broad; femur 2.67–2.68 times as long as patella; movable chelal finger 1.64 times as long as hand and 0.59 times as long as chela. Setae generally long and acuminate. Chelal hand gradually constricted towards fingers, apodeme complex of movable chelal finger strongly sclerotized. Fixed chelal finger and hand with eight trichobothria, movable chelal finger with four trichobothria, ib and isb situated close together, submedially on dorsum of chelal hand; eb, esb and ist at base of fixed chelal finger; esb slightly distal eb and ist slightly distal to esb; it slightly distal to est, situated subdistally; et slightly near to tip of fixed chelal finger, slightly close to chelal teeth; dx situated distal to et; sb slightly closer to st than to b; b and t situated subdistally, t slightly distal to it and distal to b; est situated distal to b and close to it (Figs. 41A, 43A). Microsetae (chemosensory setae) present on dorsum of chelal hand (Figs. 41B, 43B). Both chelal fingers with a row of teeth, spaced regularly along the margin, teeth smaller distally and proximally: fixed finger with 23–24 well-spaced, pointed teeth, and a modified accessory tooth on prolateral-retrolateral face (td, slightly distal to dx); movable finger with 10–11 well-spaced, pointed teeth, plus 13–15 vestigial, rounded and contiguous basal teeth.
Opisthosoma: generally typical, pleural membrane finely granulated. All tergites and sternites undivided; setae uniseriate and acuminate. Tergal chaetotaxy I–XII: 2: 2: 4: 4: 4: 4: 5: 5: 6: 4: T2T: 0. Sternal chaetotaxy IV–XII: 10: 10: 8: 9: 10: 11: 8–10: -: 2. Genital region: sternite II with 8 setae scattered on median area, genital opening slit-like, sternite III with 14–20 setae (Fig. 41F).
Legs (Fig. 43C–D): fine granulation present on anterodorsal faces of femur IV and patella IV. Leg Ⅰ: femur 1.94–2.12 times as long as patella; tarsus 2.24–2.29 times as long as tibia. Leg IV: femoropatella 2.94–3.53 times as long as deep; tibia 4.63–5.00 times as long as deep; with basal tactile setae on both tarsal segments: basitarsus 2.67 times as long as deep (TS = 0.31–0.38), telotarsus 9.75– 10.00 times as long as deep and 2.44–2.50 times as long as basitarsus (TS = 0.30–0.31). Setae of leg I (trochanter to tibia) 2–5: 7–10: 6–9: 7–8, setae of leg IV (trochanter to basitarsus) 1–2: 2: 4–6: 7–8: 6–9. Arolium not divided, slightly shorter than the simple claws.
Adult females (Figs 40B, 41G). Mostly same as males; tergal chaetotaxy Ⅰ–ⅩII: 2–3: 2–3: 4: 4: 4: 4–5: 5: 5–6: 5–6: 4: T2T: 0; sternal chaetotaxy IV–ⅩII: 11: 10: 9: 9: 10: 10: 9: -: 2. Genital region: sternite II with 12 setae scattered on median area, sternite III with a row of 12 setae.
Dimensions (length/breadth or, in the case of the legs, length/depth in mm; ratios in parentheses). Males: body length 1.53–1.56. Pedipalps: trochanter 0.19–0.20/0.10– 0.11 (1.73–2.00), femur 0.64–0.67/0.10 (6.40–6.70), patella 0.24–0.25/0.12 (2.00–2.08), chela 0.95/0.16–0.19 (5.00–5.94), hand 0.36/0.16–0.19 (1.89–2.25), movable chelal finger length 0.59. Chelicera 0.38–0.40/0.20–0.21 (1.90), movable finger length 0.22. Carapace 0.39– 0.41/0.40–0.43 (0.95–0.98). Leg I: trochanter 0.13/0.09 (1.44), femur 0.35–0.36/0.05–0.06 (5.83–7.20), patella 0.17–0.18/0.05–0.06 (2.83–3.60), tibia 0.17/0.04– 0.05 (3.40–4.25), tarsus 0.38–0.39/0.04 (9.50–9.75). Leg IV: trochanter 0.14–0.19/0.11–0.12 (1.27–1.58), femoropatella 0.53/0.15–0.18 (2.94–3.53), tibia 0.35– 0.37/0.07–0.08 (4.63–5.00), basitarsus 0.16/0.06 (2.67), telotarsus 0.39–0.40/0.04 (9.75–10.00).
Females: body length 1.50–1.83. Pedipalps: trochanter 0.13–0.22/0.11–0.13 (1.18–1.83), femur 0.69– 0.76/0.11–0.14 (5.43–6.55), patella 0.25–0.28/0.12–0.14 (2.00–2.15), chela 1.00–1.11/0.17–0.19 (5.84–5.94), hand 0.39–0.44/0.17–0.19 (2.28–2.32), movable chelal finger length 0.61–0.68. Chelicera 0.45–0.50/0.21–0.24 (1.88–2.17), movable finger length 0.24–0.26. Carapace 0.40–0.47/0.43–0.50 (0.93–0.96). Leg I: trochanter 0.11– 0.13/0.10–0.11 (1.00–1.30), femur 0.37–0.40/0.06–0.07 (5.43–6.17), patella 0.18–0.22/0.06 (3.00–3.67), tibia 0.17–0.19/0.04–0.05 (3.60–4.75), tarsus 0.40–0.45/0.04– 0.05(8.80–11.25).Leg IV:trochanter0.17–0.19/0.10–0.12 (1.56–1.70), femoropatella 0.50–0.59/0.17–0.20 (2.80– 3.10), tibia 0.37–0.40/0.08–0.09 (4.44–5.00), basitarsus 0.17–0.18/0.06 (2.83–3.00), telotarsus 0.40/0.04 (10.00– 11.50).
Remarks. Lagynochthonius maanensis was described from two female specimens by Hou, Feng & Zhang (2023). In a recent collection trip, some new specimens were collected at the type locality (Pianxiao Cave in Zunyi City, Guizhou Province, China), including two males and one female, which conform to the diagnostic characteristics of L. maanensis. A refined diagnosis was provided in this study.
Lagynochthonius maanensis most closely resembles L. tuoluoensis in the absence of intercalary teeth, the presence of two setae on tergites I–II, the presence of four setae on III–IV, and the absence of eyes or eyespots on the carapace, but differs in following combination of characters: chelal finger 1.64 (♂), 1.55–1.61 (♀) times longer than hand and hand 1.89–2.25 (♂), 2.28–2.32 (♀) times as long as broad compared to chelal finger 1.56– 1.59 (♂), 1.48–1.50 (♀) times longer than hand and hand 2.27–2.43 (♂), 2.35–2.38 (♀) times as long as broad in L. tuoluoensis (Hou et al. 2023a).
Ecology. All specimens were collected under rocks and mud inside the cave.
Distribution. Known only from the type locality (China, Guizhou Province).
description: Published as part of SUN, JIANZHOU, GUO, XIANGBO & ZHANG, FENG, 2024, A review of the genus Lagynochthonius Beier, 1951 (Pseudoscorpiones, Chthoniidae) from China, pp. 177-250 in Megataxa 12 (2) on pages 225-231, DOI: 10.11646/megataxa.12.2.1, http://zenodo.org/record/15002032