Pilbarana lowryi Stringer & King sp. nov.

(Figs. 5–7)

urn:lsid:zoobank.org:act: 35C8B0FC-98EE-411E-8AD8-C93784B618B0

Material examined. Holotype: female, WAM C78833 (10:7951; GenBank COI: OK170015, 28S: OK257013), Solomon Mine Project, Valley of the Kings Iron Deposit, 60 km north of Tom Price, WA, 22°09′45.36ʺS 117°53′39.36ʺE, coll. P. Bell and E. S. Volschenk, 20 January 2010 . Paratypes: 1 female, WAM C78834 (10:0087; GenBank COI: OK170006, 28S: OK257012), Cappers Well, 70 km north of Tom Price, WA, 22°03′44.62ʺS 117°59′57.77ʺE, coll. S. Eberhard and S. Catomore, 7 October 2010 ; 1 male WAM C76988 (10:0082; GenBank COI: OP160221), Pigeon Well Bore, 70 km north of Tom Price, WA, 22°01′51.04ʺS 118°03′32.81ʺE, coll. S. Eberhard and S. Catomore, 7 October 2010 .

Diagnosis. Head with antennal sinus concave. Antenna 1 peduncular article 1 slightly longer than article 2. Antenna 2 peduncular articles 4–5 distinctly shorter than length of head; flagellum equal in length to peduncular article 5. Gnathopod 1 propodus approximately 2 times as long as broad; carpus approximately 3.5 times as long as broad. Pereopods 3–4 coxae with indistinct anterior lobe. Uropod 1 peduncle with one robust basofacial seta. Uropod 2 peduncle longer than inner ramus.

Description. Holotype female. Length 8.7 mm. Head (Fig. 5A) with antennal sinus concave or rounded, anteroventral corner rounded. Antenna 1 (Fig. 5B) peduncular article 1 slightly longer than article 2; peduncular article 3 around one third length of article 2; flagellum of 18 articles, with one ventral aesthetasc on proximal margin of most articles. Antenna 2 (Fig. 5C) slender, around two thirds length of antenna 1; peduncular article 4 approximately equal in length to peduncular article 5, both articles shorter than length of head; flagellum of 7 articles, equal in length to peduncular article 5. Mandible (Fig. 5D) palp article 1 twice as long as broad, around half length of articles 2 and 3, articles 2 and 3 approximately equal in length. Maxilla 1 (Fig. 5E) outer plate with six denticulate robust setae. All other mouthparts (Figs. 5F, G) as in generic description.

Gnathopod 1 (Fig. 6A) coxa anteriorly projected with one associated seta, posterodistal corner reduced; propodus approximately 2 times as long as broad; carpus approximately 3.5 times as long as broad. Gnathopod 2 (Figs. 6B) coxa anteriorly projected with associated setae; propodus approximately 2 times as long as broad. Pereopods 3–4 (Figs. 6C, D) coxae with indistinct anterior lobe. Pereopod 5 (Fig. 6E) coxa anterior lobe gradually less distinct, with associated seta, posterior lobe very small.

Uropod 1 (Fig. 7A) peduncle with one robust basofacial seta, row of robust setae along dorsal margin. Uropod 2 (Fig. 7B) peduncle longer than inner ramus, row of setae along dorsal margin. Uropod 3 (Fig. 7C) outer ramus cylindrical with 2 articles, first article approximately 1.5 times length of second article.

Distribution. 60–70 km north of Tom Price, Fortescue River Basin, Pilbara, Western Australia.

Etymology. Named in honour of Dr Jim Lowry for his substantial and valuable contribution to Australian amphipod taxonomy.

Remarks. Specimens of P. lowryi sp. nov. were sampled from three bores within the Fortescue River Basin near the Hamersley Range in the central area of the Pilbara, approximately 60–70 km north of the town of Tom Price (Fig. 1). The holotype specimen was collected from a deposit within the Solomon Mining Project, while paratypes were sampled from bores outside the impacted region. These specimens were found to be morphologically identical, and molecular analyses revealed relatively low molecular COI divergence estimates of between 2.8–3.1%. These divergences suggest some slight phylogeographic structuring of populations, potentially due to distance between collection sites, but are, nonetheless, within the range of amphipod intraspecific variation (Tempestini et al. 2018; King et al. 2022). In addition, no juveniles were examined and so should be assessed in further collections, and no morphological differences were observed between males and females (as for P. grandis sp. nov.).