Spelaeochthonius yinae, Yun-Chun LI, 2023

Yun-Chun LI, 2023, Three new species of pseudoscorpions (Arachnida: Pseudoscorpiones: Pseudotyrannochthoniidae) from caves in Yunnan and Guizhou Provinces, China, European Journal of Taxonomy 861, pp. 48-64 : 56-60

Spelaeochthonius yinae sp. nov.

urn:lsid:zoobank.org:act:022ECCAC-A3CD-4BD4-876D-3167FD2CF413

Figs 3 , 5A–B

Diagnosis

Differs from the other members of the genus Spelaeochthonius by the following combination of characters: carapace without eyes or eyespots, anterior margin with 6 setae, posterior margin with 2 setae (male 15 setae, female 16 setae); epistome present, composed of 6 teeth, heavily sclerotised; cheliceral hand with 5 lyrifissures, fixed cheliceral finger with large subapical tooth, rallum with 11 blades; and male coxae I with 7 coxal blades, female with 8 coxal blades, each terminally trifurcate blades; fixed chelal finger with 23 acute teeth, movable chelal finger with 14 teeth. Tergite I–II each with 2 setae. Pedipalpal femur (♂) 7.65 ×, (♀) 7.26 × as long as broad, length (♂) 1.30 mm, (♀) 1.38 mm; chela (♂) 5.93 ×, (♀) 6.30 × as long as broad, length (♂) 1.72 mm, (♀) 1.89 mm; ratio movable chelal finger/chelal hand (♂) 1.36 ×, (♀) 1.40 ×.

Etymology

The specific epithet was given in honour of Mrs Hao-Min Yin due to the assistance provided during fieldwork.

Type material

Holotype CHINA • ♂; Yunnan Province, Zhaotong City, Doushaguan Town, Xiao Cave ; 28°02.405′ N, 104°06.845′ E; 708 m a.s.l.; 11 Apr. 2017; Yun-Chun Li leg.; MCWNU ( Ar-Ps-YN-0081 ).

Paratype CHINA • 1 ♀; same collection data as for holotype; MCWNU ( Ar-Ps-YN-0008 ) .

Description

Adult male

COLOURS. Chelicerae, pedipalps, and legs reddish brown, remaining parts yellow brown.

CARAPACE ( Fig. 3A–B ). Subquadrate, 0.90 × as long as broad, without furrows; lateral margins constricted posteriorly, eyes absent but eye region bulging and convex in dorsal view; epistome present, composed of 6 teeth, heavily sclerotised. With 15 setae arranged 6: 2: 3: 2: 2.

CHELICERA. Relatively broad. Cuticle of hand gently granulate to squamate. Hand with 6 setae and 5 lyrifissures, all setae acuminate, movable finger with 1 seta in medial position, galea present as a very low mound. Fixed finger with 1 medium-sized distal tooth and 11 progressively smaller proximal teeth; movable finger with 12 teeth ( Fig. 3C ). Serrula exterior with 22 lamellae; serrula interior with 18 lamellae. Rallum composed of 11 blades with fine barbules, basal-most 1 distinctly shorter than others ( Fig. 3E ).

PEDIPALP ( Fig. 3H–J ). All setae acuminate. Hand of chela narrowed at base of fingers. Trochanter 1.56 ×, femur 7.65 ×, patella 2.33 × as long as broad, femur 3.10 × as long as patella. Chela 5.93 ×, hand 2.48 × as long as broad; movable chelal finger 1.36 × as long as hand. Fixed finger with 23 acute teeth, with middle ones larger than that in both ends; movable finger with 14 teeth. Fixed chelal finger with 8 trichobothria and movable finger with 4, eb, esb, ib, isb, and ist located basally of the fixed finger, it and est distomedial and forming a pair, it slightly more distal than est; et subdistal and duplex xs distal; on movable finger, st subproximal and in medial position on finger, triplet sb, b, and t distomedial to distal, distance between sb and b almost equal to distance between b and t.

ABDOMEN. Tergal chaetotaxy (I–XII): 2: 2: 4: 4: 4: 6: 7: 7: 6: 6: 4: 0; sternal chaetotaxy (IV–XII): 13: 11: 10: 11: 10: 12: 10: 0: 2. Manducatory process with 2 setae. Pedipalpal coxa with 3 setae, coxa I 6, II 6, III 5, IV 4–5 setae; intercoxal tubercle present with 2 setae. Coxae I with 7 coxal blades, each terminally trifurcate blades ( Fig. 3D ). Anterior genital operculum with 9 setae, without lyrifissures; genital opening with 8 setae on the right side and 7 on the left ( Fig. 3L ).

LEGS ( Fig. 3F–G ). Leg I: trochanter 1.34 × as long as deep, femur 7.40 × as long as deep and 2.00 × as long as patella, patella 4.11 × as long as deep, tibia 4.57 × as long as deep, tarsus 13.00 × as long as deep. Leg IV: trochanter 1.56 × as long as deep, femur+ patella 4.62 × as long as deep, femur shorter than patella, tibia 6.55 × as long as deep, metatarsus 3.78 × as long as deep, tarsus 15.00 × as long as deep. Metatarsus with 1 tactile seta (sub-basal, TS = 0.20), tarsus with 1 tactile seta (sub-basal, TS = 0.18). Subterminal tarsal setae not distally serrate, arolium slightly shorter than claws and not divided; all claws simple.

Adult female

Mostly the same as the holotype.

CARAPACE. 0.97 × as long as broad. With a total of 16 setae, including 6 on the anterior margin and 4 on the posterior margin.

PEDIPALP. Trochanter 1.58 × as long as broad, femur 7.26 × as long as broad, patella 2.47 × as long as broad, femur 2.94 × as long as patella. Chela 6.30 × as long as broad, hand 2.5 × as long as broad; movable finger 1.40 × as long as hand.

ABDOMEN. Tergal chaetotaxy (I–XII): 2: 2: 4: 4: 4: 5: 6: 7: 5: 5: 2: 0; sternal chaetotaxy (IV–XII): 11: 11: 10: 10: 11: 11: 7: 0: 2. Coxae I with 8 coxal blades, each terminally trifurcate blades. Genital opening slit-like, anterior genital operculum with 6 setae, with 2 lyrifissures ( Fig. 3M ).

DIMENSIONS (length/width or, in the case of the legs, length/depth in mm). Male (female in parentheses): body length 2.64 (3.06). Carapace 0.53/0.59 (0.61/0.63). Pedipalp: trochanter 0.28/0.18 (0.30/0.19), femur 1.30/0.17 (1.38/0.19), patella 0.42/0.18 (0.47/0.19), hand 0.72/0.29 (0.75/0.30), length of movable chelal finger 0.98 (1.05), chela 1.72/0.29 (1.89/0.30). Leg I: trochanter 0.22/0.16 (0.24/0.18), femur 0.74/0.10 (0.80/0.11), patella 0.37/0.09 (0.42/0.10), tibia 0.32/0.07 (0.35/0.08), tarsus 0.78/0.06 (0.82/0.07). Leg IV: trochanter 0.25/0.16 (0.32/0.17), femur+patella 0.97/0.21 (1.04/0.22), tibia 0.72/0.11 (0.78/0.12), metatarsus 0.34/0.09 (0.38/0.08), tarsus 0.90/0.06 (0.95/0.08).

Distribution

China (Yunnan).

Habitat

The cave was about 5–20 m high, 15–80 m wide, and its length was unknown. The new species were collected from under damp, shaded gravel about 80 m from the cave entrance. At the same time, some species of spiders, millipedes and neobisiid pseudoscorpions were also collected.

Figures

Fig. 3. Spelaeochthonius yinae sp. nov. A–L. ♂, holotype (MCWNU (Ar-Ps-YN-0081)). M. ♀, paratype (MCWNU (Ar-Ps-YN-0008)). A. Carapace. B. Epistome C. Right chelicera. D. Coxal spines. E. Rallum of left chelicera. F. Left leg I, lateral view. G. Left leg IV, lateral view. H. Left pedipalp (minus chela). I. Chela, retrolateral view. J. Chela, dorsal view. K. Intercoxal tubercle. L. Male genital area. M. Female genital area. Scale bars = 0.20 mm.

Fig. 5. Spelaeochthonius yinae sp. nov., dorsal views. A. ♂, holotype (MCWNU (Ar-Ps-YN-0081)). B. ♀, paratype (MCWNU (Ar-Ps-YN-0008)). Scale bar = 1.00 mm.