Ozestheria jonnae, 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 : 75-78

Ozestheria jonnae sp. nov.

urn:lsid:zoobank.org:act:71618CD3-D915-4CCC-94D4-B170CFA699F8

Fig. 24

Ozestheria sp. O – Schwentner et al. 2015a: figs 2, 6; 2020: figs 1–2. — Hethke et al. 2023: fig. 11.

Diagnosis

Ozestheria jonnae sp. nov. is characterized by a long condyle and a narrow occipital notch; carapace ornamentation dorsally on carapace punctate, in following growth bands anastomosing lirae forming ventrally within growth band, lirae become longer, more pronounced and less anastomosing within progressing growth bands; male rostrum with weakly convex anterior margin, apex nearly rectangular, usually rounded, ventral margin usually with weak notch anteriorly then slightly convex; female rostrum anterior margin with dorsal indentation then slightly convex, apex rectangular and rounded, ventral margin convex; 10–15 (male) or 9–15 (female) antenna I lobes reaching to antenna II flagellomeres VI– VIII (male) or II–VI (female); 11–18 (male) or 11–18 (female) antenna II flagellomeres; 20–21 complete thorax segments; 9–24 telsonic spines of variable size and spacing, spines mostly conical, small and widely spaced with 1–3 larger spines interspersed, posterior spines thinner, elongated (aciculate); 2–14 furcal setae.

Differential diagnosis

Ozestheria jonnae sp. nov. can be differentiated from many other species of Ozestheria by the narrow occipital notch and long condyle in combination with the carapace ornamentation (dominated by subparallel and reticulating lirae), except from O. cancellata comb. nov., O. minor comb. nov., O. typica comb. nov., O. fuersichi sp. nov., O. marthae sp. nov., O. selmae sp. nov., O. radiata sp. nov., O. bourkensis sp. nov., O. rincewindi sp. nov., O. barcaldinensis sp. nov., O. ngamurru sp. nov., O. beleriandensis sp. nov., O. quinlanae sp. nov., O. glabra sp. nov., O. pilbarensis sp. nov. and O. weeksi sp. nov., and differentiating these species can be difficult, though O. jonnae differs from all of these species by an indentation dorsally on the anterior margin of the female rostrum. Furthermore, O. minor comb. nov., O. typica , O. bourkensis , O. selmae sp. nov., O. radiata , and O. beleriandensis can be differentiated by having at least the posterior half of the telsonic spines long, elongate and aciculate and O. fuersichi by its polygonal reticulations on the first few growth bands, the more widely spaced lirae on the carapace, the elongate and slender male rostrum and distinctly larger interspersed telsonic spines. The male rostrum of O. jonnae with its convex anterior and ventral margin and rounded apex has a more rounded appearance than those of O. minor , O. fuersichi sp. nov., O. marthae sp. nov., O. rincewindi sp. nov., O. ngamurru sp. nov., O. beleriandensis , and O. pilbarensis sp. nov. The number of antenna II flagellomeres in females of O. jonnae usually exceeds that of O. typica , O. marthae , O. weeksi , O. bourkensis , O. beleriandensis , O. radiata , and O. selmae .

Etymology

The species is named after Jonna Schwentner, the youngest daughter of MS.

Type material

Holotype

AUSTRALIA – Queensland • ♂; Yarromere Station, Morra Creek (M1); 21°28′51.9″ S, 145°49′34.0″ E; 3 Apr. 2009; M. Schwentner and B.V. Timms leg.; GenBank no: KJ705872 ( COI); AM P.91644.

Paratypes AUSTRALIA – Queensland • 1 ♂, 9 ♀♀; same data as for holotype; GenBank nos: KJ705353, KJ705860 to KJ705862, KJ705866, KJ705874 to KJ705877, KJ705879 ( COI); AM P.80861, P.91632

to P.91634, P.91638, P.91643, P.91646–91649 • 1 ♀; same data as for holotype; GenBank no: KJ705859 ( COI); NHMW-ZOO-CR-28484 .

Other material examined

AUSTRALIA – Queensland • 2 ♂♂, 3 ♀♀; Yarromere Station , small pool (Y7); 21°34′38.6″ S, 145°48′07.7″ E; 4 Apr. 2009; M. Schwentner and B.V. Timms leg.; AM P.91622, P.91623, P.91635 to P.91637 • 2 ♀♀; Yarromere Station , small pool (Y8); 21°33′29.5″ S, 145°47′06.5″ E; 4 Apr. 2009; M. Schwentner and B.V. Timms leg.; AM P.91624, P.91625 • 1 ♂, 4 ♀♀; Yarromere Station , small pool (Y23); 21°34′26.9″ S, 145°46′46.4″ E; 4 Apr. 2009; M. Schwentner and B.V. Timms leg.; AM P.91626 to P.91627 • 2 ♂♂, 3 ♀♀; Yarromere Station , small pool (Y29); 21°30′38.8″ S, 145°48′48.1″ E; 5 Apr. 2009; M. Schwentner and B.V. Timms leg.; AM P.91617 to P.91621 • 1 ♂; pool close to Lake Dunn , 22°36′16.4″ S, 145°40′21.8″ E; 14 Feb. 2010; M. Schwentner, C. Sieves and B.V. Timms leg.; AM; P.91645 .

Additional material (not examined)

AUSTRALIA – Queensland • 5 juvs; Lake Galilee ; 22°25′37.3″ S, 145°42′13.4″ E; 15 Feb. 2010; M. Schwentner, C. Sieves and B.V. Timms leg.; AM P.91639 to P.91642, P.91650 .

Type locality

Australia, Queensland, Yarromere Station, Morra Creek (M1), 21°28′51.9″ S, 145°49′34.0″ E.

Description

Males

CARAPACE ( Fig. 24a, e–f). Length 5.2–8.1 mm (HT: 6.8 mm), height 3.2–5.3 mm (HT: 4.3 mm). Coloration dark reddish-brown, usually dorsal and central parts of carapace more reddish, other parts darker (sometimes nearly black), outer margin yellowish. 34–107 (HT: 41) growth lines, 12–28 (HT: 28) in first set of widely spaced growth lines, following crowded growth lines in many individuals with interspersed set of widely spaced (secondary growth phases) growth lines (up to two secondary growth phases).

CARAPACE SHAPE. Dorsal margin straight, dorso-posterior corner distinct or rounded (HT: distinct). Posterior margin broadly rounded, suboval, equicurvate to infracurvate (b/H 0.46–0.56, HT: 0.46). Ventral margin widely rounded. Umbo position submedian (Cr/L 0.25–0.30; HT: 0.28).

CARAPACE ORNAMENTATION ( Fig. 24c–d, g–h). Larval valve and first few growth bands appear smooth to granular, in some individuals with punctae (smooth and/or granular growth bands are an artifact of abrasion or dirt). Following growth bands punctate (may appear granular) dorsally within growth bands, and with anastomosing lirae forming ventrally within growth bands; with progressing growth bands lirae more pronounced and covering full growth band. Crowded growth bands with pronounced, parallel lirae, terminating in moniliform nodule on concentric ridge. Concentric ridges shallow. Setae filiform, mainly preserved close to carapace margin; under SEM a single irregular row of setal pores along all growth lines.

HEAD ( Fig. 24j). Condyle long, distally acute (short and rounded in one individual); occipital notch narrow. Condyle with anterobasal hump. Margin between condyle and ocular tubercle straight to slightly concave. Ocular tubercle weakly developed, forming obtuse (~110–140°) angle with rostrum. Anterior margin of rostrum weakly convex. Apex nearly rectangular, usually rounded. Ventral margin of rostrum usually with weak notch anteriorly, then slightly convex. Naupliar eye subtriangular to suboval or subrectangular with rounded edges. Antenna I long with 10–15 lobes (HT: 13), reaching to antenna II flagellomeres VI–VIII (HT: VII). Antenna II with 11–18 flagellomeres (HT: 11).

THORAX. 21–22 (HT: 22) segments, 21 thoracopod-bearing and none to one (HT: one) posterior limbless segment not reaching dorsal margin. Last ~⅔ of thoracopod-bearing segments with spine bearing dorsal extensions. Dorsal extensions increasing in size posteriorly over successive segments (until ~7 th last segment). Spines short and stout.

THORACOPOD III (only P.91618; Fig. 24l). Endite I short and curved dorsally. Endites II–V broad, decreasing in size. Endite V palp two-segmented, basal segment longer than endopod. Exopod ventral extension subequal in extension to endopod, dorsal extension wide, narrowing distally, overreaching epipod. Epipod long, cylindric.

TELSON ( Fig. 24m –n). 15–21 spines (HT: 19). First (anterior) spine enlarged. Spines relatively evenly sized and spaced, mostly conical, small and widely spaced. 1–3 larger and stouter spines interspersed. Posterior spines thinner, elongate (aciculate), some enlarged and more irregularly spaced. Anterior two-thirds of dorsal margin nearly straight, posteriorly concavely curved. Right terminal claw more strongly curved than left (one individual with left claw more strongly curved).

FURCA ( Fig. 24m –n). Proximally with dorsomedial longitudinal row of 5–14 (HT: 12) setae, row ending distally in a single conical spine. Distal part ⅔ of furcal length, with numerous small denticles.

Females

Overall appearance as in males. Carapace ( Fig. 24b) length 5.6–7.7 mm (mean: 6.8 mm), height 3.9– 5.1 mm (mean: 4.5 mm); 32–72 (mean: 46) growth lines, 12–33 (mean: 22) widely spaced (primary growth phase), crowded growth bands often intermitted by widely space growth bands of secondary growth phase (up to four secondary growth phases); Cr/L 0.24–0.30 (mean: 0.26) and b/H 0.46–0.57 (mean: 0.52). Angle between head and rostrum usually obtuse as in males, rarely close to straight ( Fig. 24k). Anterior margin of rostrum with dorsal indentation, then slightly convex; apex rectangular, less rounded compared to males; ventral margin strongly convex (rarely only weakly convex). Antenna I with 9–15 small lobes (mean: 11), lobes smaller than in males; reaching to antenna II flagellomeres II–VI (mean: IV). Antenna II with 11–18 flagellomeres (mean: 14). 21–22 (mean: 21) segments, 20–21 (mean: 21) thoracopod-bearing and none to one posterior limb-less segment not reaching dorsal margin. Telson with 9–24 (mean: 15) dorsal spines; left and right terminal claws equally curved or right slightly stronger. Furca with 2–10 setae (mean: 6).

Distribution ( Fig. 24o)

Known only from central Queensland in the northern parts of the Cooper Creek catchment (in the region around Lake Galilee and Lake Dunn).

Remarks

The carapace shape of Ozestheria jonnae sp. nov. ( Fig. 6) is distinct from that of most other species and overlaps partly with those of O. jiangi sp. nov., O. minor comb. nov., O. timmsi sp. nov. (marginally), O. frederikeae sp. nov., O. marthae sp. nov. (marginally), O. selmae sp. nov., O. cancellata comb. nov., O. weeksi sp. nov. (marginally), O. quinlanae sp. nov. (marginally), O. glabra sp. nov., O. echidna sp. nov. and O. pilbarensis sp. nov. (marginally).