Paraplatyarthrus cunyuensis Javidkar and King, sp. nov.

Figs 8–10, 2 B–C, 20A

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Type material. Holotype: Male, WAM C 54809 (BES17212.2), State Barrier Fence calcrete, Cunyu pastoral station, Eastern Murchison region , Western Australia, Australia; 25.7642°S, 120.1143°E, May 2012, coll. W.F. Humphreys & S.J.B. Cooper.

Paratypes: 1 female (WAM C 54813, BES17212.1) (Same locality and collection data as holoptype); 3 females (WAM C 54810, BES17217; WAM C 54811, BES17217.1; WAM C 54812, BES17217.2), 25.7726°S, 120.1108°E, May 2012, coll. W.F. Humphreys & S.J.B. Cooper; 4 females (WAM C 54814, BES15090.2; WAM C 66911, BES15090.1; WAM C 66912, BES15090.3; WAM C 54815, BES15081.1), 25.78064°S, 120.10745°E, March 2009, coll. W.F. Humphreys & S.J.B. Cooper; 1 male (WAM C 54816, BES15081.2), 25.78064°S, 120.10745°E, March 2009, coll. W.F. Humphreys & S.J.B. Cooper. All paratypes from State Barrier Fence calcrete, Cunyu pastoral station, Eastern Murchison region, Western Australia, Australia.

Diagnosis. Eyes with 1 reduced orange ommatidium-like component (vestigial) without external eye structure. Male genital lobe apically truncated, subapically protruded.

Description. Male (WAM C 54809), Body completely pale (Fig. 2 B). Cephalon lateral lobes present but not enlarged. Eyes with 1 reduced orange ommatidium-like component (vestigial) with no external eye structure (Fig. 2 C). Antenna 1 medial article shortest, distal and basal articles same size but longer than medial one (Fig. 8 A). Antenna 2 flagellum with basal article short about 1/3 of distal article (Fig. 8 B). Left mandible (Fig. 8 C) pars molaris with about 5 plumose setae; hairy lobe bearing 2 plumose setae. Right mandible pars molaris with few long plumose setae; 1 relatively long plumose seta on hairy lobe, 1 smaller set a bit lower. Maxilla 1 outer endite (Fig. 8 D) with outer group of 4 teeth covering about 65% of marginal area, inner group of 2 cleft, 2 truncated and 1 simple tooth; inner endite (Fig. 8 E) with no fine setae on subapical outer marginal corner. Maxilla 2 (Fig. 8 F) apically bilobate, inner lobe smaller than outer one, fine suture delimiting lobes. Maxillipedal endite (Fig. 8 G) with 1 large seta close to subapical inner corner; distal articles of palp with 1 long proximal seta, 2 medial smaller setae and apical tuft of few long setae, 2 small setae on medial outer margin of palp.

Epimeron 1 rounded anteriorly. In dorsal view, posterolateral corner of pereonites 1–3 rounded. Posterolateral corner of pereonites 4–7 posteriorly directed (Fig. 20 A). Pleonal epimeron 5 posterior corner not surpassing uropodal sympodite. Tergite 7 with noduli laterales relatively at same distance to posterior margin. Noduli Laterales with D/C ratios not constant in tergites 1–7.

Pereopod 1 carpus inner margin not dense, with few long and short serrate setae, tuft of fine setae present (Fig. 9 A); propodus with both small simple and large serrate setae; dactylus with long fine seta not surpassing claws, outer claw relatively straight, with small depression on medial part. Pereopod 7 not showing any sexual dimorphism (Fig. 9 B). Pleon outline continuous with pereon. Pleopod 1 endopodite (Fig. 10 A) with simple apex, distal part with very fine small setae; exopodite heart-shaped, posterior point not developed (Fig. 10 B). Genital papilla ventral sheath apically pointed and surpassed by long lobe which is apically truncated and subapically protruded (Fig. 9 C). Pleopod 2, 3 and 5 exopodites with 1 marginal simple seta (Fig. 10 C, D, F). Pleopod 4 exopodite with 2 marginal setae (Fig. 10 E). Pleotelson triangular, with rounded tip. Uropodal exopodites welldeveloped and surpassing pleotelson; endopodites slightly exceeding pleotelson, insertion point at almost same level as exopodite; sympodite with extended circumflex-shaped incision, with rounded apex (not reaching proximal sympodite) on outer side (Fig. 9 D).

Etymology. The species name refers to its confined distribution in the Cunyu calcrete aquifer.

Remarks. Paraplatyarthrus cunyuensis sp. nov. appears in the same clade with P. occidentoniscus sp. nov. (Fig. 1) from which it has a COI divergence of 15.9% (Appendix 1). The new species is easily distinguishable based on its pale body and the occurrence of 1 reduced orange ommatidium-like component (vestigial) with no external eye structure. The body length of P. cunyuensis varies between 3.0 mm and 4.5 mm, and the pleotelson is somewhat pointed in a few individuals. This species was referred to as Taxon 7 in Javidkar et al. (2015). It is restricted to a single calcrete aquifer, Cunyu State Barrier Fence calcrete, Eastern Murchison region, Western Australia.