Indohya silenda 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 : 95-97

Indohya silenda Harvey & Burger , n. sp.

( Figs. 1–3 , 5 , 52 , 53 )

urn:lsid:zoobank.org:act:F69277D0-9F8A-4E4C-B565-54DAB7D66D19

Material examined. Holotype deutonymph. AUSTRALIA: Western Australia: Western Ridge, ca. 5 km SW. of Newman , 23°24′51.12″S, 119°33′31.95″E, 1 February–7 April 2020, troglofauna trap, depth 20 metres, M.K. Curran, A.J. Mittra ( WAM T140487 ).

Diagnosis. Indohya silenda is a blind troglobite that differs from all other Indohya species for which sequence data are available by a synapomorphy in COI mtDNA: at base 538 there is a substitution to G. The single sequenced specimen differs from all other sequenced specimens of Indohya by 16.5–26.2% (Table 2).

Description (deutonymph). Colour ( Fig. 52 ): Very pale, yellow-white.

Chelicera: hand with 5 setae, movable finger with 1 sub-medial seta.

Pedipalp: trochanter 2.11 ×, femur 6.12 ×, patella 3.58 ×, chela (with pedicel) 4.72 ×, chela (without pedicel) 4.66 ×, hand (without pedicel) 1.81 × longer than broad, movable finger 1.41 × longer than hand (without pedicel). Fixed finger with 6 trichobothria ( Fig. 53B ), eb, est, et, ib, ist and it present; movable finger with 2 trichobothria, b and t present. Fixed chelal finger with 39 low teeth ( Fig. 53B ); movable chelal finger with 23 low teeth.

Cephalothorax: carapace 1.31 × longer than broad; with 12 setae, arranged 4: 0: 4: 2: 2; without furrows; eyes absent. Coxal chaetotaxy 3: 3: 3: 3.

Abdomen: missing.

Legs: all missing.

Dimensions (mm): holotype ( WAM T140487 ). Pedipalp: trochanter 0.190 / 0.090 , femur 0.520 / 0.085, patella 0.340 / 0.095, chela (with pedicel) length 0.755 / 0.160, chela (without pedicel) length 0.745, hand (without pedicel) length 0.290, movable finger length 0.410. Carapace 0.360 / 0.275.

Distribution and remarks. This blind, troglobitic species is currently represented only by a single deutonymph collected from Western Ridge in the south-western Pilbara region of Western Australia ( Fig. 5 ). Based on available sequence data (Table S4), this species is noticeably different from other species, and the sole specimen is situated on a long genetic branch ( Figs. 1–3 ). The species was previously known by WAM identification code Indohya ‘PSE172’.

Conservation assessment. Indohya silenda is only known from a subterranean biotope, but it is unknown whether it is more widely distributed in the local area. The total extent of the subterranean habitat and I. silenda ’s distribution is unknown. Despite relatively intensive subterranean sampling of the area, no more specimens have been collected of this species. The species may be impacted by future mining developments but insufficient information is available currently to determine its status using the criteria developed by the International Union for Conservation of Nature (2012).

Etymology. The specific epithet refers to the use of molecular sequence data to establish that this nymphal specimen represents a distinct species (silendum, Latin, mystery, secret) ( Brown 1956).

Kimberley fauna

Figures

FIGURE 1. Maximum likelihood phylogeny of Hyidae and other neobisioids, based on alignment of concatenated COI, 18S and 28S. Ultrafast bootstrap values are presented for nodes greater than 80%.

FIGURE 2. Maximum likelihood phylogeny of Australian Indohya, using COI, 18S and 28S concatenated dataset. Bootstrap values are presented for all nodes. The genes amplified for each specimen are depicted with black squares in the gene matrix.

FIGURE 3. Maximum likelihood phylogeny of Australian Indohya, using COI. Bootstrap values are presented for all nodes.

FIGURE 5. Maps of north-western Australia depicting recorded distributions of the subterranean species of Indohya from the Pilbara and Cape Range region.

FIGURE 52. Indohya silenda Harvey & Burger, n. sp., holotype deutonymph (WAM T140487): A, dorsal; B, ventral; C, cephalothorax, dorsal. Scale lines = 1.0 mm.

FIGURE 53. Indohya silenda Harvey & Burger, n. sp., holotype deutonymph (WAM T140487): A, left chela, retrolateral; B, left fixed finger, chelal teeth, retrolateral. Scale lines = 0.25 mm (Fig. A), 0.1 mm (Fig. B).