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: PQ 426999 , 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.

Figures

Fig. 29. Ozestheria matuwa sp. nov. a–d. Carapace. a. Male, holotype (WAM C78010). b. Female (WAM C80202). c. Dorsal view, male, holotype (left valve only; WAM C78010). d. Male, paratype (WAM C80208), SEM. e–h. Carapace ornamentation (male paratype WAM C80208; positions marked in a, d and f by rectangles), SEM. e. Dorsal carapace. f. Mid-carapace. g. Ventral carapace. h. Midcarapace, detail. i. Carapace ornamentation (male, holotype WAM C78010), ventral.j–l. Head (antennae not shown). j. Male, holotype (WAM C78010). k. Female (WAM C80202). l. Female (WAM C80212). m–n. Telson. m. Male, holotype (WAM C78010). n. Male (WAM C80209). o. Third left thoracopod (holotype, WAM C78010). p. Distribution map (produced in ArcMap 10.7; see caption Fig. 7 for sources). Scale bars: a–d =1 mm; e–g, i =0.2 mm; h= 0.05 mm; j–o =0.5 mm.

Fig. 5. Morphometrics of short-condyled species. Scores on upper PC1 and PC2 of Fourier shape coefficients of 248 outlines, including 233 new individuals and 15 historic type specimens, four of which are drawings ofOzestheria elliptica (Sars, 1897),O. lutraria (Brady, 1886) andO. berneyi (Gurney, 1927). One of the drawings of O. berneyi corresponds to the studied syntype. The names used by Schwentner et al. (2015a) to identify genetically delimited species (e.g., C, D etc.; extended for the newly identified species, e.g., X1) are provided. New specimens are represented by convex hulls, type specimens by data points. lower. Mean shape of each species, calculated based on up to 73 individuals per species.