Research Article |
Corresponding author: Feng Zhang ( dudu06042001@163.com ) Academic editor: Fedor Konstantinov
© 2024 Jianzhou Sun, Xiangbo Guo, Feng Zhang.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Sun J, Guo X, Zhang F (2024) Five new epigean Lagynochthonius species (Pseudoscorpiones, Chthoniidae) from southern China. ZooKeys 1198: 101-134. https://doi.org/10.3897/zookeys.1198.115609
|
Five new Lagynochthonius species of the pseudoscorpion family Chthoniidae are described, based on morphological characters: Lagynochthonius duo sp. nov., Lagynochthonius gibbus sp. nov., Lagynochthonius hepingensis sp. nov., Lagynochthonius houi sp. nov., and Lagynochthonius sanhuaensis sp. nov. All specimens were collected from epigean habitats in southern China.
Morphology, new species, pseudoscorpion, taxonomy
The genus Lagynochthonius Beier, 1951, belonging to the family Chthoniidae Daday, 1889, subfamily Chthoniinae Daday, 1889, tribe Tyrannochthoniini Chamberlin, 1962, was erected by
Lagynochthonius pseudoscorpions usually live in litter layer or soil, under rocks and stones, in caves. At present, this chthoniid genus contains 79 species, of which 32 are distributed in China (
The specimens examined for this study are preserved in 75% ethyl alcohol in a refrigerator at -20 °C and deposited in the Museum of Hebei University (MHBU) (Baoding, China). Photographs and measurements were taken using a Leica M205A stereomicroscope equipped with a Leica DFC550 camera. Drawings was made using the Inkscape software (v. 1.0.2.0). Detailed examination was conducted with an Olympus BX53 general optical microscope. All images were edited and formatted using Adobe Photoshop 2017.
Terminology and measurements follow
The following abbreviations are used in the text: for the chelal trichobothria: b = basal; sb = sub-basal; st = subterminal; t = terminal; ib = interior basal; isb = interior sub-basal; ist = interior sub-terminal; it = interior terminal; eb = exterior basal; esb = exterior sub-basal; est = exterior sub-terminal; et = exterior terminal. For other abbreviations: af, apical sensilla of fixed chelal finger, am, apical sensilla of movable chelal finger; dx, duplex trichobothria; p1–2, proximal sensilla of movable chelal finger; sc, microsetae (chemosensory setae); td, modified tooth.
Subfamily Chthoniinae Daday, 1889
Tribe Tyrannochthoniini Chamberlin, 1962
Chthonius johni Redikorzev, 1922, by original designation.
Holotype ♂ (Ps.-MHBU-GX2022080201): China, Guangxi, Guilin City, Longsheng Autonomous County, Longji Town, Anjiangping Area, under topsoil and in the leaf litter layer [25°42′15.15″N, 110°3′3.87″E], 419 m a.s.l., 2 August 2023, Kun Yu & Jianzhou Sun leg. Paratypes: 3 ♂ (Ps.-MHBU-GX2022080203–05) and 1 ♀ (Ps.-MHBU-GX2022080202), all with the same data as the holotype.
The specific name is derived from the Latin word duo, meaning dual, which refers to the presence of two setae on both tergites I and II. A noun in apposition.
(♂♀). Moderately sized epigean species; carapace with four eyes, anterior margin smooth and epistome triangular; tergites I and II each with two setae, III and IV each with four setae. Rallum with eight blades. Pedipalps slender, chela 6.17–7.27 (♂), 5.06 (♀) × as long as broad; femur 5.60–6.67 (♂), 6.70 (♀) × as long as broad; only fixed chelal finger with intercalary teeth and a modified accessory tooth (td) on prolateral-retrolateral face; chemosensory setae (sc) present on dorsum of chelal hand; sensilla present.
Males (holotype and paratypes) (Figs
Lagynochthonius duo sp. nov., holotype male (A–F) paratype female (G): A left chela (lateral view) B left chela (dorsal view) C right chelicera (dorsal view) D carapace (dorsal view) E Left pedipalp (minus chela, dorsal view) F male genital area (ventral view) G female genital area (ventral view).
Color generally pale yellow, chelicerae, carapace, pedipalps and tergites slightly darker.
Cephalothorax
(Figs
Chelicera
(Figs
Pedipalp
(Figs
Lagynochthonius duo sp. nov., holotype male A left chela (lateral view), with details of teeth and trichobothrial pattern B left chela (dorsal view) C Leg I (lateral view) D leg IV (lateral view). Abbreviations: for the chelal trichobothria: b = basal; sb = sub-basal; st = subterminal; t = terminal; ib = interior basal; isb = interior sub-basal; ist = interior sub-terminal; it = interior terminal; eb = exterior basal; esb = exterior sub-basal; est = exterior sub-terminal; et = exterior terminal. For other abbreviations: af, apical sensilla of fixed chelal finger, am, apical sensilla of movable chelal finger; dx, duplex trichobothria; p1–2, proximal sensilla of movable chelal finger; td, modified tooth.
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: 4–5: 5–7: 5–6: 4: T2T: 0. Sternal chaetotaxy IV–XII: 8–10: 10–12: 11–12: 10–11: 10–12: 10–12: 9: -: 2. Genital region: sternite II with 6–10 setae scattered on median area, genital opening slit-like, sternite III with 18–20 setae (Fig.
Legs
(Fig.
Adult female (paratype) (Figs
Dimensions (length/breadth or, in the case of the legs, length/depth in mm; ratios in parentheses). Males: body length 1.24–1.44. Pedipalps: trochanter 0.16–0.17/0.09 (1.78–1.89), femur 0.56–0.60/0.09–0.10 (5.60–6.67), patella 0.21–0.24/0.09–0.10 (2.30–2.56), chela 0.74–0.80/0.11–0.12 (6.17–7.27), hand 0.34–0.37/0.11–0.12 (2.83–3.27), movable chelal finger length 0.41–0.44. Chelicera 0.29–0.33/0.16–0.17 (1.76–1.94), movable finger length 0.20–0.21. Carapace 0.34–0.36/0.35–0.38 (0.95–0.97). Leg I: trochanter 0.10–0.12/0.08 (1.25–1.50), femur 0.29–0.33/0.06 (4.83–5.50), patella 0.17/0.05–0.06 (2.83–3.40), tibia 0.15–0.17/0.04 (3.75–4.25), tarsus 0.32–0.35/0.04 (8.00–8.75). Leg IV: trochanter 0.15–0.17/0.10 (1.50–1.70), femoropatella 0.45–0.53/0.16–0.20 (2.65–2.81), tibia 0.33–0.36/0.06–0.08 (4.38–5.14), basitarsus 0.15–0.17/0.05–0.06 (2.50–3.20), telotarsus 0.36–0.39/0.03–0.04 (9.25–12.00).
Females: body length 1.57. Pedipalps: trochanter 0.17/0.11 (1.54), femur 0.67/0.10 (6.70), patella 0.26/0.11 (2.36), chela 0.91/0.18 (5.06), hand 0.44/0.18 (2.44), movable chelal finger length 0.49. Chelicera 0.37/0.21 (1.76), movable finger length 0.23. Carapace 0.38/0.43 (0.88). Leg I: trochanter 0.18/0.10 (1.80), femur 0.35/0.07 (5.00), patella 0.18/0.06 (3.00), tibia 0.18/0.06 (3.00), tarsus 0.39/0.04 (9.75). Leg IV: trochanter 0.19/0.11 (1.73), femoropatella 0.59/0.22 (2.68), tibia 0.38/0.08 (4.75), basitarsus 0.18/0.07 (2.57), telotarsus 0.42/0.04 (10.50).
Lagynochthonius duo sp. nov. differs from all other epigean species of the genus Lagynochthonius from China except L. medog by the tergal chaetotaxy I–IV: 2: 2: 4: 4. It differs from L. medog in the presence of an epistome, which is absent in L. medog, and in the presence of only fixed chelal fingers with intercalary teeth in L. duo sp. nov., whereas both chelal fingers have intercalary teeth in L. medog (
China (Guangxi).
Holotype ♂ (Ps.-MHBU-GZ2022070301): China, Guizhou Province, Tongren City, Jiangkou County, 500 m near Wanjiatun, under topsoil and in the leaf litter layer [27°43′32.5″N, 108°41′17.9″E], 509 m a.s.l., 3 July 2022, Yanmeng Hou, Lu Zhang, Nana Zhan, Jianzhou Sun & Long Lin leg. Paratype: 1 ♀ (Ps.-MHBU-GZ2022070302), all with the same data as the holotype, 2 ♂ (Ps.-MHBU-GZ2022062805–06) and 2 ♀ (Ps.-MHBU-GZ2022062803–04): Tongren City, Sinan County, Zhangjiazhai Town, 700 m near Zhangjiaping, under topsoil and in the leaf litter layer [27°56′39.16″N, 108°4′21.8″E], 731 m a.s.l., 28 June 20, Yanmeng Hou, Lu Zhang, Nana Zhan, Jianzhou Sun & Long Lin leg.
The specific name is derived from the Latin word gibbus, meaning hump-shaped, which refers to the shape of epistome. A noun in apposition.
(♂♀). Moderately sized epigean species; carapace with four eyes, anterior margin smooth and epistome hump-shaped; tergites I–IV each with four setae. Rallum with eight blades. Pedipalps slender, chela 6.64–7.00 (♂), 5.12–5.69 (♀) × as long as broad; femur 5.78–7.00 (♂), 5.64–6.33 (♀) × as long as broad; only fixed chelal finger with intercalary teeth and a modified accessory tooth (td) on prolateral-retrolateral face; chemosensory setae (sc) present on dorsum of chelal hand; sensilla present.
Males (holotype and paratypes) (Figs
Color generally pale yellow, chelicerae, carapace, pedipalps and tergites slightly darker.
Cephalothorax
(Figs
Lagynochthonius gibbus sp. nov., holotype male (A–F) paratype female (G): A left chela (lateral view) B left chela (dorsal view) C right chelicera (dorsal view) D carapace (dorsal view) E left pedipalp (minus chela, dorsal view) F male genital area (ventral view) G female genital area (ventral view).
Chelicera
(Figs
Pedipalp
(Figs
Lagynochthonius gibbus sp. nov., holotype male A left chela (lateral view), with details of teeth and trichobothrial pattern B left chela (dorsal view) C leg I (lateral view) D leg IV (lateral view). Abbreviations: for the chelal trichobothria: b = basal; sb = sub-basal; st = subterminal; t = terminal; ib = interior basal; isb = interior sub-basal; ist = interior sub-terminal; it = interior terminal; eb = exterior basal; esb = exterior sub-basal; est = exterior sub-terminal; et = exterior terminal. For other abbreviations: af, apical sensilla of fixed chelal finger, am, apical sensilla of movable chelal finger; dx, duplex trichobothria; p1–2, proximal sensilla of movable chelal finger; td, modified tooth.
Opisthosoma
: generally typical, pleural membrane finely granulated. All tergites and sternites undivided; setae uniseriate and acuminate. Tergal chaetotaxy I–XII: 4: 4: 4: 4: 4: 4: 5–6: 6–7: 6: 4: T2T: 0. Sternal chaetotaxy IV–XII: 10–12: 12–16: 10–13: 12–13: 12–13: 11–12: 9–10: -: 2. Genital region: sternite II with eight setae scattered on median area, genital opening slit-like, sternite III with 18–24 setae (Fig.
Legs
(Fig.
Adult females (paratypes) (Figs
Dimensions (length/breadth or, in the case of the legs, length/depth in mm; ratios in parentheses). Males: body length 1.23–1.39. Pedipalps: trochanter 0.16–0.17/0.09 (1.78–1.89), femur 0.52–0.56/0.08–0.09 (5.78–7.00), patella 0.20–0.23/0.08–0.09 (2.33–2.56), chela 0.73–0.77/0.11 (6.64–7.00), hand 0.34–0.35/0.11 (3.09–3.18), movable chelal finger length 0.39–0.42. Chelicera 0.29–0.30/0.15–0.17 (1.71–2.00), movable finger length 0.18–0.19. Carapace 0.33–0.35/0.34–0.35 (0.97–1.03). Leg I: trochanter 0.10–0.11/0.08–0.09 (1.11–1.38), femur 0.28–0.30/0.06 (4.67–5.00), patella 0.17–0.18/0.05 (3.40–3.60), tibia 0.15–0.16/0.04 (3.75–4.00), tarsus 0.33/0.03–0.04 (8.25–11.00). Leg IV: trochanter 0.10–0.17/0.10–0.11 (1.00–1.70), femoropatella 0.48–0.50/0.16–0.20 (2.50–3.06), tibia 0.31–0.33/0.07 (4.43–4.71), basitarsus 0.14–0.17/0.03–0.04 (2.33–3.40), telotarsus 0.36/0.03–0.04 (9.00–12.00).
Females: body length 1.64–1.82. Pedipalps: trochanter 0.16–0.19/0.09–0.11 (1.60–1.78), femur 0.57–0.64/0.09–0.11 (5.64–6.33), patella 0.23–0.26/0.08–0.12 (1.92–2.30), chela 0.79–0.91/0.15–0.17 (5.12–5.69), hand 0.38–0.43/0.15–0.17 (2.53–2.69), movable chelal finger length 0.42–0.48. Chelicera 0.34–0.38/0.19–0.22 (1.72–1.79), movable finger length 0.21–0.24. Carapace 0.35–0.40/0.39–0.44 (0.88–0.91). Leg I: trochanter 0.12–0.13/0.07–0.09 (1.33–1.71), femur 0.29–0.33/0.06–0.07 (4.71–5.50), patella 0.16–0.19/0.04–0.06 (2.67–4.75), tibia 0.15–0.18/0.04–0.05 (3.60–3.75), tarsus 0.34–0.37/0.04 (8.50–9.25). Leg IV: trochanter 0.16–0.17/0.10–0.14 (1.14–1.70), femoropatella 0.49–0.56/0.18–0.22 (2.52–2.72), tibia 0.33–0.37/0.06–0.08 (4.50–4.71), basitarsus 0.17–0.19/0.06 (2.83–3.17), telotarsus 0.36–0.43/0.03–0.04 (10.00–12.00).
Lagynochthonius gibbus sp. nov. most closely resembles L. duo sp. nov. due to the presence of intercalary teeth only on the fixed chelal finger, the presence of eight blades on rallum, and similar size (chela length of males 0.73–0.80 mm, females 0.79–0.91 mm). However, the new species differs from L. duo sp. nov. in the shape of the epistome which is hump-shaped in L. gibbus sp. nov., but triangular in L. duo sp. nov., and in the number of setae on tergites I and II, with four setae on each in L. gibbus sp. nov. compared to two setae on each in L. duo sp. nov.
China (Guizhou Province).
Holotype ♂ (Ps.-MHBU-GZ2022080701): China, Guizhou Province, Qianxinan Prefecture, Wangmu County, Dayi Town, Heping Village, Near Provincial Highway 209, under topsoil and in the leaf litter layer [25°23′54.8″N, 106°7′37.08″E], 1553 m a.s.l., 7 August 2022, Yanmeng Hou, Lu Zhang, Jianzhou Sun & Wenlong Fan leg. Paratypes: 5 ♂ (Ps.-MHBU-GZ2022080702–06) and 2 ♀ (Ps.-MHBU-GZ2022080707–08), all with the same data as the holotype.
Named after the Heping Village, the type locality. A noun in apposition.
(♂♀). Moderately sized epigean species; carapace with four eyes, anterior margin smooth and epistome hump-shaped; tergites I–IV each with four setae. Rallum with seven blades. Pedipalps slender, chela 6.08–6.82 (♂), 5.33–5.44 (♀) × as long as broad; femur 6.25–7.00 (♂), 6.20–6.30 (♀) × as long as broad; both chelal fingers with intercalary teeth, fixed chelal finger with a modified accessory tooth (td) on prolateral-retrolateral face; chemosensory setae (sc) present on dorsum of chelal hand; sensilla present.
Males (holotype and paratypes) (Figs
Color generally pale yellow, chelicerae, carapace, pedipalps and tergites slightly darker.
Cephalothorax
(Figs
Lagynochthonius hepingensis sp. nov., holotype male (A–F) paratype female (G): A left chela (lateral view) B left chela (dorsal view) C left chelicera (dorsal view) D carapace (dorsal view) E left pedipalp (minus chela, dorsal view) F male genital area (ventral view) G female genital area (ventral view).
Chelicera
(Figs
Pedipalp
(Figs
Lagynochthonius hepingensis sp. nov., holotype male A left chela (lateral view), with details of teeth and trichobothrial pattern B left chela (dorsal view) C leg I (lateral view) D leg IV (lateral view). Abbreviations: for the chelal trichobothria: b = basal; sb = sub-basal; st = subterminal; t = terminal; ib = interior basal; isb = interior sub-basal; ist = interior sub-terminal; it = interior terminal; eb = exterior basal; esb = exterior sub-basal; est = exterior sub-terminal; et = exterior terminal. For other abbreviations: af, apical sensilla of fixed chelal finger, am, apical sensilla of movable chelal finger; dx, duplex trichobothria; p1–2, proximal sensilla of movable chelal finger; td, modified tooth.
Opisthosoma
: generally typical, pleural membrane finely granulated. All tergites and sternites undivided; setae uniseriate and acuminate. Tergal chaetotaxy I–XII: 4: 4: 4: 4: 4: 4–5: 5–6: 5–7: 5–6: 4: T2T: 0. Sternal chaetotaxy IV–XII: 8–12: 10–12: 10–13: 10–12: 11–12: 10–12: 9: -: 2. Genital region: sternite II with 10 setae scattered on median area, genital opening slit-like, sternite III with 16–18 setae (Fig.
Legs
(Fig.
Adult females (paratypes) (Figs
Dimensions (length/breadth or, in the case of the legs, length/depth in mm; ratios in parentheses). Males: body length 1.18–1.38. Pedipalps: trochanter 0.14–0.16/0.08–0.10 (1.50–1.78), femur 0.50–0.56/0.08–0.09 (6.25–7.00), patella 0.19–0.23/0.08–0.09 (2.11–2.88), chela 0.67–0.75/0.10–0.12 (6.08–6.82), hand 0.31–0.35/0.10–0.12 (2.83–3.10), movable chelal finger length 0.37–0.42. Chelicera 0.26–0.32/0.16–0.18 (1.63–1.81), movable finger length 0.15–0.18. Carapace 0.31–0.37/0.34–0.38 (0.89–1.09). Leg I: trochanter 0.10–0.12/0.07–0.10 (1.20–1.57), femur 0.26–0.30/0.05–0.06 (4.50–6.00), patella 0.15–0.16/0.05–0.06 (2.67–3.20), tibia 0.13–0.16/0.04 (3.25–4.00), tarsus 0.29–0.33/0.03–0.04 (7.25–11.00). Leg IV: trochanter 0.14–0.18/0.10–0.11 (1.36–1.63), femoropatella 0.44–0.50/0.17–0.20 (2.40–2.67), tibia 0.29–0.33/0.07–0.08 (4.00–4.71), basitarsus 0.13–0.15/0.05–0.06 (2.50–2.80), telotarsus 0.34–0.37/0.03–0.04 (8.75–11.67).
Females: body length 1.34–1.43. Pedipalps: trochanter 0.15–0.18/0.11–0.12 (1.25–1.64), femur 0.63–0.64/0.10 (6.20–6.30), patella 0.24–0.25/0.11–0.12 (2.08–2.18), chela 0.83–0.87/0.15–0.16 (5.33–5.44), hand 0.41–0.44/0.15–0.16 (2.73–7.75), movable chelal finger length 0.51–0.52. Chelicera 0.34–0.39/0.20 (1.70–1.95), movable finger length 0.21–0.23. Carapace 0.38–0.39/0.42 (0.90–0.93). Leg I: trochanter 0.11–0.13/0.09–0.10 (1.10–1.44), femur 0.32/0.06–0.07 (4.57–5.33), patella 0.16–0.17/0.06 (2.67–2.83), tibia 0.16–0.17/0.05 (3.2–3.4), tarsus 0.34–0.35/0.04–0.05 (6.80–8.75). Leg IV: trochanter 0.16–0.18/0.11–0.12 (1.45–1.50), femoropatella 0.54–0.55/0.18–0.21 (2.62–3.00), tibia 0.33–0.35/0.08–0.09 (3.89–4.12), basitarsus 0.16/0.06 (2.67), telotarsus 0.39/0.04 (9.75).
Lagynochthonius hepingensis sp. nov. most closely resembles L. tonkinensis in the presence of intercalary teeth on both chelal fingers and the presence of four setae on both tergal chaetotaxy I–II. However, it differs by the presence of a hump-shaped epistome and four well-developed eyes, whereas L. tonkinensis has a flat, rounded epistome and spot-like posterior pair of eyes (
China (Guizhou Province).
Holotype ♂ (Ps.-MHBU-GZ2022080901): China, Guizhou Province, Qiannan Prefecture, Pintang County, Tangbian Town, Xindian Village, under topsoil and in the leaf litter layer [25°37′42.19″N, 106°43′55.15″E], 991 m a.s.l., 9 August 2022, Yanmeng Hou, Lu Zhang, Jianzhou Sun & Wenlong Fan leg. Paratypes: 2 ♂ (Ps.-MHBU-GZ2022080902–03) and 1 ♀ (Ps.-MHBU-GZ2022080904), all with the same data as the holotype.
This species is named for Yanmeng Hou, who participated in field work and collected some of the specimens. A noun in apposition.
(♂♀). Moderately sized epigean species; carapace with four eyes, anterior margin smooth and epistome triangular; tergites I and II each with two setae, III and IV each with four setae. Rallum with eight blades. Pedipalps slender, chela 6.31–6.75 (♂), 5.20 (♀) × as long as broad; femur 5.90–6.78 (♂), 6.25 (♀) × as long as broad; chelal fingers without intercalary teeth, fixed chelal finger with a modified accessory tooth (td) on prolateral-retrolateral face; chemosensory setae (sc) present on dorsum of chelal hand; sensilla present.
Males (holotype and paratypes) (Figs
Color generally pale yellow, chelicerae, carapace, pedipalps and tergites slightly darker.
Cephalothorax
(Figs
Lagynochthonius houi sp. nov., holotype male (A–F) paratype female (G): A left chela (lateral view) B left chela (dorsal view) C left chelicera (dorsal view) D carapace (dorsal view) E left pedipalp (minus chela, dorsal view) F male genital area (ventral view) G female genital area (ventral view).
Chelicera
(Figs
Pedipalp
(Figs
Lagynochthonius houi sp. nov., holotype male A left chela (lateral view), with details of teeth and trichobothrial pattern B left chela (dorsal view) C leg I (lateral view) D leg IV (lateral view). Abbreviations: for the chelal trichobothria: b = basal; sb = sub-basal; st = subterminal; t = terminal; ib = interior basal; isb = interior sub-basal; ist = interior sub-terminal; it = interior terminal; eb = exterior basal; esb = exterior sub-basal; est = exterior sub-terminal; et = exterior terminal. For other abbreviations: af, apical sensilla of fixed chelal finger, am, apical sensilla of movable chelal finger; dx, duplex trichobothria; p1–2, proximal sensilla of movable chelal finger; td, modified tooth.
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: 4: 5–6: 5–8: 4: T2T: 0. Sternal chaetotaxy IV–XII: 10: 10–11: 8–10: 8–10: 9–10: 9–10: 9: -: 2. Genital region: sternite II with 8–9 setae scattered on median area, genital opening slit-like, sternite III with 16–18 setae (Fig.
Legs
(Fig.
Adult female (paratype) (Figs
Dimensions (length/breadth or, in the case of the legs, length/depth in mm; ratios in parentheses). Males: Body length 1.29–1.41. Pedipalps: trochanter 0.17–0.18/0.08–0.09 (2.00–2.12), femur 0.59–0.61/0.09–0.10 (5.90–6.78), patella 0.22–0.24/0.09–0.10 (2.30–2.67), chela 0.77–0.82/0.12–0.13 (6.31–6.75), hand 0.39–0.42/0.12–0.13 (3.23–3.25), movable chelal finger length 0.38–0.41. Chelicera 0.29–0.32/0.17 (1.71–1.88), movable finger length 0.17–0.19. Carapace 0.32–0.36/0.35–0.37 (0.91–0.97). Leg I: trochanter 0.11–0.12/0.07–0.09 (1.33–1.57), femur 0.31–0.35/0.07–0.09 (5.50–6.20), patella 0.14–0.17/0.04–0.05 (2.80–4.25), tibia 0.16–0.18/0.04 (4.00–4.50), tarsus 0.36–0.39/0.03–0.04 (9.75–12.67). Leg IV: trochanter 0.17–0.19/0.10–0.13 (1.31–1.72), femoropatella 0.54–0.56/0.17–0.21 (2.67–3.29), tibia 0.35–0.37/0.06–0.07 (5.00–5.83), basitarsus 0.16–0.18/0.05–0.06 (2.67–3.60), telotarsus 0.39–0.42/0.03–0.04 (10.50–13.00).
Females: body length 1.68. Pedipalps: trochanter 0.22/0.11 (2.00), femur 0.75/0.12 (6.25), patella 0.28/0.13(2.15), chela 1.04/0.20 (5.20), hand 0.55/0.12 (2.75), movable chelal finger length 0.50. Chelicera 0.41/0.24 (1.71), movable finger length 0.25. Carapace 0.40/0.47 (0.85). Leg I: trochanter 0.13/0.12 (1.08), femur 0.40/0.08 (5.00), patella 0.21/0.07 (3.00), tibia 0.21/0.06 (3.50), tarsus 0.46/0.05 (9.20). Leg IV: trochanter 0.21/0.14 (1.50), femoropatella 0.67/0.25 (2.68), tibia 0.43/0.08 (5.38), basitarsus 0.22/0.07 (3.14), telotarsus 0.51/0.05 (10.20).
Lagynochthonius houi sp. nov. differs from all other epigean species of the genus Lagynochthonius from China except L. duo sp. nov. by the following combination of characters: the presence of a triangular epistome and the presence of two setae on tergite I and II (
Lagynochthonius houi sp. nov. differs from L. duo sp. nov. in the length of the movable chelal finger which is 0.95–1.05 × as long as the hand in males and 0.91 × as long as the hand in female, whereas in L. duo sp. nov. it is 1.11–1.27 × as long as the hand in males and 1.11 × as long as hand in female. Additionally, L. houi sp. nov. lacks intercalary tooth on the chelal fingers, whereas the fixed chelal finger posesses intercalary teeth in L. duo sp. nov.
China (Guizhou Province).
Holotype ♂ (Ps.-MHBU-GZ2022070201): China, Guizhou Province, Tongren City, Yinjiang County, 500 m near Sanhua Mountain, under topsoil and in the leaf litter layer [27°53′40.73″N, 108°32′46.16″E], 818 m a.s.l., 7 July 2022, Yanmeng Hou, Lu Zhang, Nana Zhan, Jianzhou Sun & Long Lin leg. Paratypes: 2 ♂ (Ps.-MHBU-GZ2022070203 & GZ2022070205) and 2 ♀ (Ps.-MHBU-GZ2022070202 & GZ2022070204), all with the same data as the holotype.
Named after the Sanhua Mountain, near the type locality. A noun in apposition.
(♂♀). Moderately sized epigean species; carapace with four eyes, anterior margin smooth and epistome hump-shaped; tergites I–IV each with four setae. Rallum with seven blades. Pedipalps slender, chela 6.80–7.89 (♂), 5.31–5.40 (♀) × as long as broad; femur 6.50–6.63 (♂), 5.70–6.00 (♀) × as long as broad; chelal fingers without intercalary teeth, fixed chelal finger with a modified accessory tooth (td) on prolateral-retrolateral face; chemosensory setae (sc) present on dorsum of chelal hand; sensilla present.
Males (holotype and paratypes) (Figs
Color generally pale yellow, chelicerae, carapace, pedipalps and tergites slightly darker.
Cephalothorax
(Figs
Lagynochthonius sanhuaensis sp. nov., holotype male (A–F) paratype female (G): A left chela (lateral view) B left chela (dorsal view) C left chelicera (dorsal view) D carapace (dorsal view) E left pedipalp (minus chela, dorsal view) F male genital area (ventral view) G female genital area (ventral view).
Chelicera
(Figs
Pedipalp
(Figs
Lagynochthonius sanhuaensis sp. nov., holotype male A left chela (lateral view), with details of teeth and trichobothrial pattern B left chela (dorsal view) C leg I (lateral view) D leg IV (lateral view). Abbreviations: for the chelal trichobothria: b = basal; sb = sub-basal; st = subterminal; t = terminal; ib = interior basal; isb = interior sub-basal; ist = interior sub-terminal; it = interior terminal; eb = exterior basal; esb = exterior sub-basal; est = exterior sub-terminal; et = exterior terminal. For other abbreviations: af, apical sensilla of fixed chelal finger, am, apical sensilla of movable chelal finger; dx, duplex trichobothria; p1–2, proximal sensilla of movable chelal finger; td, modified tooth.
Opisthosoma
: generally typical, pleural membrane finely granulated. All tergites and sternites undivided; setae uniseriate and acuminate. Tergal chaetotaxy I–XII: 4: 4: 4: 4: 4: 4–6: 4–6: 5–6: 6: 4: T2T: 0. Sternal chaetotaxy IV–XII: 10–12: 10–11: 11–13: 9–13: 10–12: 10–12: 9: -: 2. Genital region: sternite II with ten setae scattered on median area, genital opening slit-like, sternite III with 16–18 setae (Fig.
Legs
(Fig.
Adult females (paratypes) (Figs
Dimensions (length/breadth or, in the case of the legs, length/depth in mm; ratios in parentheses). Males: body length 1.30–1.36. Pedipalps: trochanter 0.15/0.07–0.08 (1.88–2.14), femur 0.52–0.54/0.08 (6.50–6.63), patella 0.20–0.21/0.08–0.09 (2.22–2.50), chela 0.68–0.73/0.09–0.10 (6.80–7.89), hand 0.32–0.34/0.09–0.10 (3.20–3.67), movable chelal finger length 0.38–0.41. Chelicera 0.29–0.30/0.15–0.16 (1.81–1.93), movable finger length 0.18–0.19. Carapace 0.32–0.36/0.35–0.37 (0.91–0.97). Leg I: trochanter 0.09–0.11/0.08–0.09 (1.00–1.22), femur 0.27–0.28/0.05 (5.40–5.60), patella 0.13–0.15/0.05–0.06 (2.33–3.00), tibia 0.14–0.15/0.04–0.05 (2.80–3.75), tarsus 0.30–0.32/0.03 (10.00–10.67). Leg IV: trochanter 0.13–0.16/0.10–0.11 (1.30–1.45), femoropatella 0.46–0.48/0.16–0.18 (2.67–3.00), tibia 0.31–0.32/0.06–0.07 (4.43–5.33), basitarsus 0.14–0.15/0.04–0.06 (2.50–3.50), telotarsus 0.33–0.35/0.03–0.04 (8.75–11.67).
Females: body length 1.61–1.71. Pedipalps: trochanter 0.15–0.19/0.08–0.09 (1.67–2.38), femur 0.57–0.60/0.10 (5.70–6.00), patella 0.25–0.26/0.11 (2.27–2.36), chela 0.81–0.85/0.15–0.16 (5.2), hand 0.39–0.41/0.15–0.16 (2.75), movable chelal finger length 0.43–0.45. Chelicera 0.34–0.37/0.19–0.21 (1.76–1.79), movable finger length 0.22–0.23. Carapace 0.35–0.36/0.34–0.37 (0.82–0.88). Leg I: trochanter 0.09–0.13/0.09 (1.33–1.44), femur 0.30–0.32/0.06–0.08 (3.75–5.33), patella 0.17–0.18/0.05–0.06 (2.83–3.60), tibia 0.16–0.17/0.04–0.05 (3.20–4.25), tarsus 0.34–0.35/0.04 (8.50–8.75). Leg IV: trochanter 0.15–0.19/0.10–0.12 (1.50–1.58), femoropatella 0.49–0.54/0.21 (2.33–2.57), tibia 0.35–0.36/0.07 (5.00–5.14), basitarsus 0.15–0.16/0.06–0.07 (2.29–2.50), telotarsus 0.36–0.38/0.03–0.04 (9.50–12.00).
Lagynochthonius sanhuaensis sp. nov. most closely resembles L. niger in the absence of intercalary teeth and the presence of four setae on tergites I and II, but differs from it in several characters. First, the new species has a shorter (0.68–0.73 mm compared to 0.75–0.93 mm in L. niger) and thinner chela (6.80–7.89 × as long as broad compared to 5.17–6.25 × as long as broad in L. niger) in males. Second, the shape of the epistome is hump-shaped in L. sanhuaensis sp. nov., whereas it is triangular in L. niger. Third, the rallum has seven blades in L. sanhuaensis sp. nov., whereas it has eight blades in L. niger (
China (Guizhou Province).
1 | Tergites I and II each with two setae | 2 |
– | Tergites I and II each with four setae | 4 |
2 | Epistome present | 3 |
– | Epistome absent | L. medog Zhang & Zhang, 2014 |
3 | Only fixed chelal finger with intercalary teeth | L. duo sp. nov. |
– | Both chelal fingers without intercalary teeth | L. houi sp. nov. |
4 | At least one finger of chela with intercalary teeth | 5 |
– | Both chelal fingers without intercalary teeth | 8 |
5 | Both chelal fingers with intercalary teeth | 6 |
– | Only fixed chelal finger with intercalary teeth | 7 |
6 | Carapace with a hump-shaped epistome; the four well-developed eyes | L. hepingensis sp. nov. |
– | Carapace with a flat, rounded epistome; posterior pair of eyes spot-like | L. tonkinensis (Beier, 1951) |
7 | Carapace without epistome | L. harveyi Zhang & Zhang, 2014 |
– | Carapace with a hump-shaped epistome | L. gibbus sp. nov. |
8 | Epistome present | 9 |
– | Epistome absent | 10 |
9 | Epistome triangular; pedipalpal chela length 0.75–0.93 mm, 5.17–6.25 × as long as broad | L. niger Hu & Zhang, 2012 |
– | Epistome hump-shaped; pedipalpal chela length 0.68–0.73 mm, 6.80–7.30 × as long as broad | L. sanhuaensis sp. nov. |
10 | Four well-developed eyes | 11 |
– | Anterior pair of eyes well-developed, posterior pair of eyes reduced to eyespot | L. brachydigitatus Zhang & Zhang, 2014 |
11 | Pedipalpal chela length 0.72 mm, 4.80 × as long as broad | L. sinensis (Beier, 1967) |
– | Pedipalpal chela length 0.95–1.00 mm, 5.56–6.33 × as long as broad | L. leptopalpus Hu & Zhang, 2012 |
We are grateful to Kun Yu, Yanmeng Hou, Lu Zhang, Nana Zhan, Long Lin, and Wenlong Fan (Hebei University) for their help during the fieldwork, to subject editor Fedor Konstantinov and copy editor Nathalie Yonow and three reviewers Dr. Zhizhong Gao, Dr. Mark S. Harvey and one anonymous reviewer for their helpful suggestions that substantially improved this paper.
The authors have declared that no competing interests exist.
No ethical statement was reported.
This research is supported by the Natural Science Foundation of Hebei Province (no. C2021201030).
Writing – original draft: JS. Writing – review and editing: FZ, XG.
Jianzhou Sun https://orcid.org/0009-0001-4940-7130
Xiangbo Guo https://orcid.org/0000-0002-7074-8642
Feng Zhang https://orcid.org/0000-0002-3347-1031
All of the data that support the findings of this study are available in the main text.