Indohya sachsei Harvey & Burger, 2023

Harvey, Mark S., Burger, Mieke A. A., Abrams, Kym M., Finston, Terrie L., Huey, Joel A. & Perina, Giulia, 2023, The systematics of the pseudoscorpion genus Indohya (Pseudoscorpiones: Hyidae) in Australia, Zootaxa 5342 (1), pp. 1-119 : 111-114

Indohya sachsei Harvey & Burger , n. sp.

( Figs. 6B , 61 , 62 )

urn:lsid:zoobank.org:act:1F0446B5-D0E0-4A0D-B0CB-449FF65DC674

Material examined. Holotype female. AUSTRALIA: Western Australia: Irvine Island , bore 11DDH053, 16°05′37″S, 123°33′04″E, 30 September 2011, troglofauna trap 20 m, J. Alexander, T. Sachse ( WAM T152600 ).

Paratypes. AUSTRALIA: Western Australia: 1 ♀, Irvine Island , bore ID32, 16°05′05.64″S, 123°32′53.52″E, 1 June–1 August 2011, troglofauna trap 10 m depth, J. Alexander, S. Werner ( WAM T120199 ) ; 1 ♀, Irvine Island , bore ID27, 16°05′37.75″S, 123°33′18.66″E, 1 June–1 August 2011, troglofauna trap, 10 m, J. Alexander, S. Werner ( WAM T120196 ) .

Other material. AUSTRALIA: Western Australia: 1 protonymph, Irvine Island , bore ID32, 16°05′05.64″S, 123°32′53.52″E, 30 September 2011, troglofauna trap, depth 20 m, J. Alexander, T . Sachse ( WAM T152601 ); 1 protonymph, Irvine Island , bore ID27, 16°05′37.75″S, 123°33′18.66″E, 1 December 2011, troglofauna trap, depth 30 m, J. Alexander, A. Brown ( WAM T152603 ) .

Diagnosis. Indohya sachsei most closely resembles I. adlardi and I. rixi as all possess 14 setae on the carapace arranged 4: 2: 4: 2: 2, and they lack eyes. It differs from I. adlardi by its smaller size, e.g. chela (with pedicel) 1.22–1.27 (♀) mm (greater than 1.8 mm in I. adlardi ). It differs from I. rixi by trichobothrium sb being much closer to st than to b (ratio sb–st / sb–b = 2.63) [sb slightly closer to st than to b (ratio = 1.16) in I. rixi ], and is larger, e.g. chela (with pedicel) 1.22–1.27 (♀) mm [1.055 (Ô) mm in I. rixi ].

It also differs from all other Indohya species for which sequence data are available by a synapomorphy in COI mtDNA: at base 471 there is a substitution to G. The two sequenced specimens differ from all other sequenced specimens of Indohya by 15.3–28.2% (Table 2).

Description (adult). Colour ( Fig. 61 ): light yellow-brown, pedipalps and carapace red-brown.

Setae and cuticle: Setae long, mostly straight and acicular; most cuticular surfaces smooth and glossy.

Chelicera: surface smooth; hand with 6 setae, except for 7 setae on left chelicera of holotype, movable finger with 1 sub-medial seta, all setae acuminate; galea present, long, slender and slightly curved; fixed finger with 12 (♀) teeth, each approximately same size; movable finger with 7 (♀) teeth, each approximately same size; with 2 dorsal and 1 ventral lyrifissures; lamina exterior absent; rallum with 7 blades, all blades with anterior spinules, basal blade shorter than others.

Pedipalp ( Fig. 62B ): moderately slender; trochanter smooth, 2.26–2.38 (♀) ×; femur broadest medially, smooth, without dorsal tactile seta, with 3 stout retrolateral setae near base, 5.00–5.26 (♀) ×; patella slightly broadened distally, smooth, pedicel not strongly pronounced but basal portion slimmer than distal portion, with several small lyrifissures situated basally on dorsal surface, 3.19–3.58 (♀) ×; chela ( Fig. 62C ): hand robust, with prolateral face lightly granulate, chela (with pedicel) 3.51–4.44 (♀) ×, chela (without pedicel) 3.73–4.15 (♀) ×, hand (without pedicel) 1.44–1.71 (♀) × longer than broad, movable finger 1.31–1.52 (♀) × longer than hand (without pedicel). Fixed finger with 8 trichobothria, eb, esb and isb in straight row at base of finger, ib situated dorsally at the end of the chelal hand, isb at the basal end of the fixed finger, ib situated on dorsum of chelal hand, it closer to et than to est, et slightly distal to it; movable finger with 4 trichobothria, sb closer to b than to st, st situated much closer to t than to sb, ratio sb–st / sb–b = 2.47 (♀), t acuminate. Both fingers straight in lateral view. Fixed finger smooth, movable finger with several prolateral and retrolateral granulations basally. Chelal teeth ( Fig. 62D ) juxtadentate, fixed finger with 68 (♀), teeth 1–4, 44, 46, 50, 52, 55–64 pointed, remainder rounded, teeth of fixed finger low and flattened, movable finger with 25 (♀), low, barely discernible teeth. Venom apparatus present only in movable chelal finger, venom duct long, terminating in nodus ramosus between sb and st.

Cephalothorax: carapace ( Fig. 62A ) sub-rectangular; smooth; anterior margin slightly convex; epistome absent; lateral margins slightly convex; posterior margin straight; 1.25–1.31 (♀) × longer than broad; with 14 setae arranged 4: 2: 4: 2: 2; without furrows; eyes absent. Manducatory process distally triangular, with 2 distal setae; pedipalpal coxa with 5–6 (♀) additional setae. Coxa I with anterior margin not modified; chaetotaxy of coxae I–IV: ♀, 4: 4: 3: 5.

Legs: femora I and II much longer than patellae I and II, respectively; femora I and II with basal swelling; femora I and II with primary slit sensillum directed transversely; junction between anterior femora and patellae perpendicular; junction between posterior femora and patellae slightly oblique; femora III and IV much smaller than patellae III and IV, respectively; femur + patella IV 3.13 (♀) × longer than broad; metatarsi shorter than tarsi; subterminal tarsal seta acuminate; claws smooth, arolium slightly shorter than claws; arolium not divided.

Abdomen: tergites not divided; tergal chaetotaxy ♀, 3: 5: 6: 6: 6: 6: 6: 6: 7: 8 (including 2 tactile setae): 6 (including 2 tactile setae): 2; arranged in single rows; sternal chaetotaxy ♀, 11: (1) 8 (1): (2) 6 (2): 10: 9: 11: 12: 11: 10: 4 (including 2 tactile setae): 2; setae of anterior genital operculum (sternite II) of ♀ minute; posterior tergites and sternites with several tactile setae; medial sternites without suture line; pleural membrane uniformly granulate; without setae; stigmatic helix present.

Genitalia: female: with large gonosac that is covered with scattered pores.

Dimensions (mm): female holotype ( WAM T152600 ), followed by 2 other females, when measured. Body length (excluding chelicerae) 1.70 (1.66). Pedipalp : trochanter 0.310 / 0.130 (0.305–0.315/0.135) , femur 0.825 / 0.165 (0.815–0.850/0.155–0.165), patella 0.590 / 0.165 (0.575–0.590/0.165–0.180), chela (with pedicel) 1.265 / 0.290 (1.220–1.270/0.275–0.295), chela (without pedicel) 1.200 (1.140 –1.205), hand (without pedicel) 0.475 (0.445 – 0.505), movable finger length 0.725 (0.670). Carapace 0.570 / 0.455 (0.550–0.595/0.425–0.455) . Leg IV: femur + patella 0.595 / 0.190, tibia 0.415 / 0.085, metatarsus 0.210 / 0.065, tarsus 0.375 / 0.040.

Description (protonymph). Colour: very pale, yellow-white.

Chelicera: hand with 4 setae, movable finger without seta.

Pedipalp: trochanter 2.08 ×, femur? (crumpled) ×, patella? (crumpled) ×, chela (with pedicel) 3.96 ×, chela (without pedicel) 3.75 ×, hand (without pedicel) 1.67 × longer than broad, movable finger 1.33 × longer than hand (without pedicel). Fixed finger with 3 trichobothria ( Fig. 62E ), eb, ist and et present; movable finger with 1 trichobothrium, t present; fixed chelal finger with 28 teeth, juxtadentate, quadrate; movable chelal finger with 8 teeth.

Cephalothorax: carapace 1.25 × longer than broad; with 14 setae arranged 4: 2: 4: 2: 2; without furrows; eyes absent. Coxal chaetotaxy 1: 1: 1: 1.

Legs: metatarsi and tarsi not fused.

Abdomen: tergal chaetotaxy 4: 4: 4: 4: 4: 4: 4: 4: 4: 4: 4 (including 2 tactile setae): 2; sternal chaetotaxy 0: (0) 2 (0): (0) 2 (0): 4: 4: 4: 4: 4: 4: 4 (including 2 tactile setae): 2.

Dimensions (mm): WAM T152601 . Body length 0.78. Pedipalp: trochanter 0.135 / 0.065 , femur 0.415/? (crumpled), patella 0.195/? (crumpled), chela (with pedicel) 0.475 / 0.120, chela (without pedicel) 0.450, hand (without pedicel) length 0.200, movable finger length 0.265. Carapace 0.275 / 0.220.

Distribution and remarks. Indohya sachsei has only been collected from subterranean ecosystems on Irvine Island in the western Kimberley region ( Fig. 6B ). The sites are situated within the Northern Kimberley bioregion, and are less than 1.5 apart. Indohya sachsei co-occurs with two other species of Indohya , I. finitima and I. julianneae , and specimens of I. sachsei and I. finitima have been recovered from the same borehole. They differ in the number of carapaceal setae (14 in I. sachsei , 12 in I. finitima , the shape of the chelal hand (narrow in I. sachsei , broad in I. finitima ), and the shape of teeth of the movable chelal finger (obsolete in I. sachsei , quite distinct in I. finitima ). The species was previously known by WAM identification code Indohya ‘PSE028’.

Conservation assessment. Indohya finitima has been collected from subterranean habitats on Irvine Island, where the surface formations are intact. The species does not appear to meet the status of threatened using the criteria developed by the International Union for Conservation of Nature (2012).

Etymology. This species is named for Timothy Sachse, co-collector of the holotype.

Figures

FIGURE 6. Maps of north-western Australia depicting recorded distributions of the three epigean species of Indohya from the Kimberley:A, epigean species; B, troglobitic species.

FIGURE 61. Indohya sachsei Harvey& Burger, n. sp., holotypefemale (WAMT152600):A, dorsal; B,ventral;C, cephalothorax, dorsal. Scale lines = 1.0 mm.

FIGURE 62. Indohya sachsei Harvey & Burger, n. sp., holotype female (WAM T152600), unless stated otherwise:A, carapace, dorsal; B, right pedipalp, dorsal; C, left chela, retrolateral; D, left fixed finger, chelal teeth, retrolateral; E, left chela, retrolateral, protonymph (WAM T152601). Scale lines = 0.5 mm (Fig. B, C), 0.2 mm (Fig. A), 0.1 mm (Figs. D, E).