Ozestheria frederikeae, 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 : 54-56

Ozestheria frederikeae sp. nov.

urn:lsid:zoobank.org:act:115FEB5B-8E8B-4979-B524-087E7023A7C5

Fig. 18

Ozestheria sp. H 2 – Schwentner et al. 2015a: figs 2, 6.

Diagnosis

Ozestheria frederikeae sp. nov. is characterized by a long condyle and a narrow occipital notch; carapace ornamentation dominated by pit-like punctae, in later growth bands lirae forming between punctae; female rostrum with undulating anterior margin, apex rounded, nearly rectangular (in some individuals protruding), ventral margin straight to convex (sometimes concave mid-length); 12–14 (female) antenna I lobes reaching to antenna II flagellomeres III–IV (female); 14–17 (female) antenna II flagellomeres; 21–22 complete thorax segments; 22–31 telsonic spines, spines small with ~2 larger spines interspersed, anteriorly conical and posteriorly thin and aciculate; 6 furcal setae.

Differential diagnosis

Ozestheria frederikeae sp. nov. can be differentiated from all other species of Ozestheria by the combination of the carapace ornamentation (dominated by pit-like punctae), carapace shape, rostrum shape and telson spination. Species with similar carapace ornamentation are O. timmsi sp. nov. and O. carnegiensis sp. nov. Ozestheria timmsi differs by having a larger carapace (7.9–11.5 mm vs 6.1– 7.0 mm), more antenna flagellomeres (15–22 vs 14–17) and more complete thorax segments (23–24 vs 21). Ozestheria carnegiensis differs by having a slightly shorter and more rounded condyle, less distinct lirae on the carapace, fewer antenna flagellomeres (≤ 14 vs ≥ 14) and larger and fewer (11–20 vs 22–31) telsonic spines.

Etymology

The species is named after Frederike Korth, the wife of MS – for everything.

Type material

Holotype

AUSTRALIA – Queensland • ♀; turbid pool 80 km S of Charleville ; 27°04′59.0″ S, 146°01′42.2″ E; 17 Feb. 2010; M. Schwentner, C. Sieves and B.V. Timms leg.; GenBank no: KJ705769 ( COI); AM P.91541.

Paratypes

AUSTRALIA – Queensland • 3 ♀♀; same data as for holotype; GenBank nos: KJ705767, KJ705770, KJ705771 ( COI); AM P. 91539, P.91542, P.91543 • 1 ♀; same data as for holotype; GenBank no: KJ705768 ( COI); NHMW-ZOO-CR-28481 .

Additional material (not examined)

AUSTRALIA – Queensland • 5 juvs; big pool on Meandarra Road ; 27°22′43.9″ S, 150°01′18.1″ E; 12 Feb. 2010; M. Schwentner, C. Sieves and B.V. Timms leg.; AM P.91534 to P.91538 .

Type locality

Australia, Queensland, turbid pool 80 km S of Charleville, 27°04′59.0″ S, 146°01′42.2″ E.

Description

Females

CARAPACE ( Fig. 18a–c). Length 6.1–7.0 mm (HT: 7.0 mm), height 4.3–4.7 (HT: 4.6 mm). Coloration reddish- or orange-brown, crowded growth bands lighter. 46–52 (HT: 46) growth lines, 16–22 (HT: 20) widely spaced and 26–32 (HT: 26) crowded; in some individuals ~2–3 widely spaced growth bands recurrently interspersed between crowded growth bands (secondary growth phase).

CARAPACE SHAPE. Dorsal margin straight, dorso-posterior corner rounded. Posterior margin widely rounded, suboval, equicurvate to infracurvate (b/H 0.50–0.57, HT: 0.50). Ventral margin widely and equally rounded. Umbo anterior to submedian (Cr/L 0.23–0.26, HT: 0.24).

CARAPACE ORNAMENTATION ( Fig. 18d–g). Larval valve and first few growth bands smooth to finely granulated, under SEM finely punctate. Subsequent growth bands with irregular, poorly defined pits (punctae-like). From about mid-carapace, space between punctae raised to lirae, increasing in size on subsequent growth bands (giving the punctae an elongate, oval appearance under SEM). Crowded growth bands often too closely spaced for apparent ornamentation, else poorly defined lirae. Concentric ridges slightly raised (dorsally serrated under SEM and with small nodules in moniliform row). Setae filiform, preferentially preserved close to ventral margin; under SEM a single row of setal pores along all growth lines.

HEAD ( Fig. 18h–i). Condyle long, distally rounded; occipital notch narrow. Condyle with weak anterobasal hump. Margin between condyle and ocular tubercle straight. Ocular tubercle weakly developed, forming obtuse (~120°) to nearly straight angle with rostrum. Anterior margin of rostrum undulating: dorsally weakly convex, ventrally weakly concave. Apex rounded, nearly rectangular (in some individuals protruding). Ventral margin of rostrum straight (HT) to convex (sometimes concave mid-length). Naupliar eye elongated, subtriangular to subrectangular (rounded edges).Antenna I long with 12–14 lobes (HT: 14), reaching to antenna II flagellomeres III–IV (HT: IV). Antenna II with 14–17 flagellomeres (HT: 14).

THORAX. 21–22 (HT: 21) segments, 21 thoracopod-bearing and none to one (HT: none) posterior limbless segments not reaching dorsal margin. Mid and posterior thoracopod-bearing segments with spine bearing dorsal extensions. Dorsal extensions increase in size posteriorly over successive segments. Spines short and stout, in posterior segments central spines increase in size and the total number of spines decreases.

TELSON ( Fig. 18j–k). 22–31 spines (HT: 29). First (anterior) spine enlarged. Spines mostly tiny, conical; posterior ⅓ with slightly thinner, larger and more drawn-out spines. Spines subequal in length and spacing, few (usually two) slightly larger spines interspersed in anterior ⅔ of spines. One or a few anterior spines not arranged along dorsal margin but slightly lateral. Dorsal margin nearly straight, not concavely curved. Right terminal claw more strongly curved than left, claws notably slender.

FURCA ( Fig. 18j–k). Proximally with dorsomedial longitudinal row of 6 setae, row ending distally in a single conical spine. Distal part ½–⅔ of furcal length, with numerous small denticles.

Males

Unknown.

Distribution ( Fig. 18m)

The species is known only from two localities in southern Queensland close to the border to New South Wales. These populations are separated by ~ 400 km; thus, further populations can be assumed in this region.

Remarks

So far, only females have been collected. The second population identified by Schwentner et al. (2015a) yielded only juveniles.

Because only few specimens were available, the morphological variability of the species is not well characterized. The carapace shape of O. frederikeae sp. nov. ( Fig. 6) is distinct from that of most other species and partly overlaps with O. timmsi sp. nov. (marginally), O. jonnae sp. nov., O. cancellata comb. nov.