Carnarvonis katjae, King & Stringer & Leijs, 2023

King, Rachael A., Stringer, Danielle N. & Leijs, Remko, 2023, Carnarvonis gen. nov. and Warregoensis gen. nov.: Two New Genera and Species of Subterranean Amphipods (Crangonyctoidea: Chillagoeidae) Described from North-eastern Australia, Records of the Australian Museum (Rec. Aust. Mus.) 75 (4), pp. 447-457 : 450

Carnarvonis katjae sp. nov.

urn:lsid:zoobank.org:act:797AACEF-2E9E-46C4-BF7E-73A03D5FEA66

Figs 1–3

Holotype: QM W29606 (RL 2296.6, Genbank CO 1: OP596273.1), female, Carnarvon Station Reserve , Lady Spring, 24.80255°S 147.8265°E, Bou-Rouch pump in gravel bank, coll. R. Leijs, 15 October 2014 . Paratypes: QM W29607 , male, Carnarvon Station Reserve , Lady Spring, 24.80255°S 147.8265°E, Bou-Rouch pump in gravel bank, coll . R. Leijs, 15 October 2014 ; SAMA C14815 (RL 2296.5, Genbank CO 1: OP596271.1, OP596272.1), males and juveniles, Carnarvon Station Reserve , Lady Spring, 24.80255°S 147.8265°E, Bou-Rouch pump in gravel bank, coll . R. Leijs, 15 October 2014 .

Description. Holotype, female, 4.5 mm. Head. Without rostrum, eyes absent. Antenna 1 length less than half length of animal; peduncle with three articles progressively shorter; accessory flagellum of two articles, distal article small; flagellum of 12 articles. Antenna 2 approximately ½ length of antenna 1; peduncle longer than flagellum, articles 4–5 of peduncle of subequal length; flagellum of 4 articles. Labrum (upper lip) evenly rounded, setose apically. Labium (lower lip) without inner lobes. Mandible incisor with 5 teeth, lacinia mobilis with 4 teeth, setal row of 5 plumose setae present, molar narrow and denticulate; palp of three articles, article 3 shorter than article 2, right palp with short row of plumose setae (“D-setae”; after Lowry & Stoddart, 1993). Maxilla 1 outer plate with nine apical denticulate robust setae; inner plate with two apical plumose setae; palp of two articles, distal article longest, with apical setae. Maxilla 2 outer plate with two rows of simple and plumose setae apically and simple setae laterally; inner plate with simple setae apically and an oblique row of medial plumose setae. Maxilliped palp slender (no articles enlarged), of four articles plus spine; outer plate with robust and simple setae along apical and lateral margin; inner plate with robust and plumose setae apically and laterally.

Pereon. Gills include coxal gills on pereopods 2–6, sternal gills on thoracic segments 2–6, slender, not greater than ½ length of coxal gills. Gnathopods 1–2 not distinctly large (propodus smaller than head length). Gnathopod 1 coxa short (only slightly longer than wide), with robust seta at posterior corner and few simple setae scattered along margin; propodus length 1.5 times width, lateral face with distinct excavation above and parallel to palm margin, palm margins smooth (no distinct crenulations), without robust setae along palm margin, with 1 mesial (inner) and 1 lateral (outer) robust seta either side of palm corner (where dactyl fits to the propodus), posterior margin of propodus with 1 oblique row of long simple setae. Gnathopod 2 coxa longer than coxa 1, distinctly longer than wide, with robust seta at posterior corner and few simple setae scattered along margin; propodus length 1.8 times width, lateral face with distinct excavation above and parallel to palm margin, palm margins smooth (no distinct crenulations), without robust setae along palm margin, with 1 mesial (inner) and 1 lateral (outer) robust setae either side of palm corner (where dactyl fits to the propodus), posterior margin of propodus with 2 oblique rows of long simple setae. Pereopod 3 coxa similar length to coxa 2, longer than wide, with robust seta at posterior corner and few simple setae scattered along margin; dactylus with single seta. Pereopod 4 coxa similar length to coxa 2–3, longer than wide, small but distinct excavated corner on the posterior margin, with robust seta at posterior corner and few simple setae scattered along margin. Pereopod 5 coxa with rounded anteroventral lobe with seta, posteroventral lobe indistinct, with 1 seta on posterior margin. Pereopod 6 similar length to pereopod 7; coxa with rounded anteroventral lobe, posteroventral lobe indistinct, with 1 seta on posterior margin; basis 1.5 times as long as wide; propodus longer than carpus; dactylus with single seta. Pereopod 7 coxa rounded, with 1 seta on posterior margin; basis 1.6 times as long as wide; propodus longer than carpus; dactylus with single seta.

Pleon. Epimera 1–3 posteroventrally subquadrate, posteroventral corner with robust seta and posterior margins with several small robust setae along length; epimera 2–3 with robust setae along the ventral margin. Urosomite 1 with distinct distoventral robust seta, with paired dorsolateral setae on distal margin. Urosomite 2 with paired dorsolateral setae on distal margin. Uropod 1 peduncle without basofacial robust seta, distal margin of peduncle with group of 1 medium-large and 2 small robust setae laterally and 1 large robust seta medially. Uropod 2 distal margin of peduncle with group of 2 robust setae laterally and 1 small robust seta medially. Uropod 3 distal margin of peduncle with robust setae laterally and medially; outer ramus of 1 article, approximately 3 times length of peduncle, with clusters of 2–3 robust setae along length; inner ramus absent. Telson cleft shallowly, with robust and simple setae apically.

Etymology. Named for Dr Katja Hogendoorn, scientist and partner of Remko Leijs.

Remarks. Carnarvonis katjae sp. nov. is clearly a distinct genus and species with 15% CO1 divergence from Warregoensis lowryi sp. nov. and 22% CO1 divergence from Chillagoe thea .

Figures

Figure 1. Carnarvonis katjae sp. nov., holotype female, TL 4.5 mm, Carnarvon Station Reserve, Queensland, QM W29606. (A) whole animal in lateral view; (B) maxilla 1; (C) maxilla 2; (D) maxilliped; (E) mandible; (F) upper lip; (G) lower lip. Scale (A): 0.1 mm.

Figure 2. Carnarvonis katjae sp.nov., holotype female,TL 4.5 mm, Carnarvon Station Reserve, Queensland,QM W29606. (A) gnathopod 1; (B) gnathopod 2.

Figure 3. Carnarvonis katjae sp. nov., holotype female, TL 4.5 mm, Carnarvon Station Reserve, Queensland, QM W29606. (A) pereopod 3; (B) pereopod 6; (C) pereopod 7; (D) uropod 1; (E) uropod 2; (F) telson; (G) uropod 3.