Ozestheria matuwa, Schwentner & Hethke, 2025

Schwentner, Martin & Hethke, Manja, 2025, Revision of the Australian Ozestheria Schwentner & Richter, 2015 (Crustacea: Branchiopoda: Spinicaudata) fauna, with the descriptions of 27 new species, European Journal of Taxonomy 992, pp. 1-172 : 92-95

Ozestheria matuwa sp. nov.

urn:lsid:zoobank.org:act:4F91152F-FCDD-4306-9467-B580768A9FA0

Fig. 29

Diagnosis

Ozestheria matuwa sp. nov. is characterized by a short condyle and a wide occipital notch; a rounded ventral carapace margin; carapace ornamentation with large, well-developed polygonal reticulations, each polygon with polygonal secondary ornamentation (best seen under SEM); male rostrum with strongly convex anterior margin, apex rounded with acute to right angle, ventral margin concave, pointing apex downwards; female rostrum anterior margin straight or strongly convex, apex pointed (elongated, drawn out), ventral margin slightly concave; 12–19 (male) or 13–14 (female) antenna I lobes reaching to antenna II flagellomeres VII–IX (male) or III–IV (female); 11–14 (male) or 11–13 (female) antenna II flagellomeres; 22–24 complete thorax segments; 18–27 small, unequally sized and spaced conical telsonic spines, some spines in the central part of the telson enlarged; 3–14 furcal setae.

Differential diagnosis

See differential diagnosis of O. elliptica .

Etymology

The name is derived from Matuwa, the traditional owner’s name for the Lake Carnegie area in the Martu language; noun in apposition.

Type material

Holotype

AUSTRALIA – Western Australia • ♂; Gidgi Lake , 20 km N of Kalgoorlie; 30°36′11″ S, 121°24′51.7″ E; 18 Feb. 2014; K. Quinlan leg.; GenBank no: PQ427000 ( COI); WAM C78010 .

Paratypes

AUSTRALIA – Western Australia • 2 ♂♂; same data as for holotype; GenBank nos: PQ426999, PQ427003 ( COI); WAM C80207 , C80208 • 1 ♂; same data as for holotype; GenBank no: PQ427001 ( COI); NHMW-ZOO-CR-28496 .

Other material examined

AUSTRALIA – Western Australia • 3 ♂♂, 1 ♀; Wetland 2.4 km S of Boondi Rock; 31°11′40.4″ S, 120°23′55.7″ E; 24 Feb. 2017; K. Quinlan leg.; WAM C78006 , C80204 to C80206 • 1 ♂, 2 ♀♀; Lindsay Gordon Lagoon , SW of Lorna Glen Homestead; 26°15′45.2″ S, 121°29′51.2″ E; 18 Mar. 2017; K. Quinlan leg.; WAM C80202 , C80203 , C80201 • 4 ♂♂, 1 ♀; Wetland 50 km SW of Bullabulling (Goldfields Woodlands Conservation Park); 31°16′44.5″ S, 120°32′36″ E; 22 Feb. 2017; K. Quinlan leg.; WAM C78007 , C80209 to C80212 .

Type locality

Western Australia, Gidgi Lake, 20 km N of Kalgoorlie, 30°36′11″ S, 121°24′51.7″ E.

Description

Males

CARAPACE ( Fig. 29a, c–d). Length 6.4–9.4 mm (HT: 9.4 mm, mean: 7.7 mm), height 3.5–5.3 (HT: 5.2 mm, mean: 4.3 mm). Coloration whitish to yellow-brownish or brown, crowded growth bands lighter, often whitish. 19–23 (HT: 22, mean: 21) growth lines, 15–20 (HT: 17, mean: 17) widely spaced and 2–7 (HT: 5, mean: 4) crowded.

CARAPACE SHAPE. Dorsal margin straight, distinct dorso-posterior corner. Posterior margin broadly rounded, suboval, supracurvate to infracurvate (b/H 0.41–0.48, HT: 0.45, mean: 0.43). Ventral margin widely rounded. Umbo position anterior (Cr/L 0.21–0.24, HT: 0.24, mean: 0.22).

CARAPACE ORNAMENTATION ( Fig. 29e–i). Larval valve with shallow reticulations. Each growth band with large, well-developed, strongly raised reticulations. Reticulations form polygonal mesh across each growth band with each polygon usually being a pentagon, hexagon or heptagon. Polygon-size increasing during ontogeny, largest in the median part of each growth band; under SEM secondary mesh or polygonal reticulation within each primary polygon (less strongly developed or absent ventrally within growth bands). Ornamentation uniform across all non-crowded growth bands, crowded growth bands either too narrow to show reticulation or with a single row of polygonal reticulations, sometimes resulting in radial appearance. Concentric ridges raised. Setae of varying length; preferentially preserved in ventral and posterior parts of the carapace. Setal pores in single, irregular row along all growth lines.

HEAD ( Fig. 29j). Condyle short, distally rounded; occipital notch wide. Condyle lacking anterobasal hump. Margin between condyle and ocular tubercle straight to slightly concave. Ocular tubercle well developed, forming obtuse, nearly rectangular (~90–120°) angle with rostrum. Anterior margin of rostrum strongly convex. Apex weakly rounded, acute to nearly rectangular (~90°), pointing slightly downwards. Ventral margin of rostrum weakly to strongly concave (HT: strongly concave), in some individuals with notch anteriorly (HT: weakly developed). Naupliar eye elongated, subtriangular to subrectangular.Antenna I long with 12–19 lobes (HT: 16; mean: 15), reaching to antenna II flagellomeres VII–IX (HT: IX; mean: VIII). Antenna II with 11–14 flagellomeres (HT: 14; mean: 13).

THORAX. 23–25 (HT: 24; mean: 24) segments, 22–24 (HT: 23; mean: 23) thoracopod-bearing and one (HT: one) posterior limbless segment not reaching dorsal margin. In most thoracopod-bearing segments dorsal extensions bearing several spines and setae, posterior segments with only few spines.

THORACOPOD III (only WAM C78010; Fig. 29o). Endite I short and curved dorsally. Endites II–V broad, decreasing in size. Endite V palp two-segmented, basal segment shorter than endopod. Exopod ventral extension subequal to slightly shorter in extension to endopod, dorsal extension wide, narrowing distally, overreaching epipod. Epipod long, cylindric.

TELSON ( Fig. 29m –n). 18–27 spines (HT: 24; mean: 22). First (anterior) spine enlarged. Spines on anterior ½ to ¾ of telson short, conical, varying in size; posterior spines thinner, elongate, aciculate, increasing in size; aciculate spines preceded by a few (usually 2) particularly small spines; 1–4 larger spines interspersed. Dorsal margin straight or anteriorly convex, then concavely curved. Right terminal claw more strongly curved than left.

FURCA ( Fig. 29m –n). Proximally with dorsomedial longitudinal row of 8–14 (HT: 9, mean: 10) setae, row ending distally in a single conical spine. Distal part ⅓–⅔ of furcal length, with numerous small denticles.

Females

Overall appearance as in males. Carapace ( Fig. 29b) length 5.6–7.4 mm, height 3.1–4.2 mm; 19–25 growth lines, 14–18 and 2–10; Cr/L 0.21–0.23 and b/H 0.42–0.47. Angle between ocular tubercle and rostrum obtuse (~120–150°) ( Fig. 29k–l). Anterior margin of rostrum strongly convex to nearly straight (slightly undulating); apex with acute angle (~50°), pointed, drawn out into acute tip; ventral margin weakly concave. Antenna I with 13–14 small lobes, lobes smaller than in males; reaching to antenna II flagellomeres III–IV. Antenna II with 11–13 flagellomeres. 24 segments, of these 23 thoracopod-bearing and one posterior limb-less segment not reaching dorsal margin. Telson with 19–23 dorsal spines; right terminal claws stronger curved. Furca with 3–8 setae.

Distribution ( Fig. 29p)

Ozestheria matuwa sp. nov. has been recorded in central and southern Western Australia.

Remarks

The carapace shape of Ozestheria matuwa sp. nov. ( Fig. 5) is distinct from that of most other species and partly overlaps with those of O. rubra , O. henryae and O. christiani sp. nov.