Ozestheria barcaldinensis, 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 : 20-23

Ozestheria barcaldinensis sp. nov.

urn:lsid:zoobank.org:act:1D00ADAC-B5C3-4FDC-AE26-23B89430783A

Fig. 7

Ozestheria sp. W – Schwentner et al. 2015a: figs 2, 6; 2020: 1–2.

Diagnosis

Ozestheria barcaldinensis sp. nov. is characterized by a long condyle and a narrow occipital notch; carapace ornamentation dorsally on carapace punctate (may appear granular), in following growth bands bearing strongly reticulating and anastomosing lirae forming ventrally within growth band, lirae become longer, less anastomosing and more pronounced with progressing growth bands posteriorly and continue to be strongly reticulating anteriorly; male rostrum with convex anterior margin, apex broadly rounded with obtuse angle, ventral margin straight; 11 (male) antenna I lobes reaching to antenna II flagellomeres V; 12 (male) antenna II flagellomeres; 21 complete thorax segments; 15 telsonic spines, anterior spines conical, posterior spines thin, aciculate and increasing in size posteriorly, one larger spine interspersed; 9 furcal setae.

Differential diagnosis

Ozestheria barcaldinensis 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 punctate ornamentation dorsally on carapace, transitioning to distinct, subparallel lirae during ontogeny), 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. jonnae sp. nov., O. rincewindi 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. Ozestheria minor , O. typica , O. bourkensis , O. selmae , O. radiata , and O. beleriandensis can be differentiated by having at least the posterior half of the telsonic spines elongate and aciculate, and O. fuersichi by its polygonal reticulations on the first few growth bands and punctae between widely spaced lirae. The strongly convex anterior margin and obtuse (not rounded but angular) apex of the male rostrum differentiates O. barcaldinensis from O. cancella , O. minor , O. typica , O. fuersichi , O. marthae , O. selmae , O. rincewindi , O. ngamurru , O. beleriandensis , O. quinlanae , O. glabra , O. pilbarensis and O. weeksi . Also, the dorsal extension of the exopod is shorter than the epipod in the male 3. thoracopod of O. barcaldinensis .

Etymology

The species is named after the Barcaldine region in central Queensland, where the species is known to occur.

Type material

Holotype

AUSTRALIA – Queensland • 1 ♂; swamp on Texas Station , 72 km N of Jericho; 23°02′37.5″ S, 145°52′34.6″ E; 14 Feb. 2010; M. Schwentner, C. Sieves and B.V. Timms leg.; GenBank no: KJ706083 ( COI); AM P.91858.

Type locality

Australia, Queensland, swamp on Texas Station, 72 km N of Jericho, 23°02′37.5″ S, 145°52′34.6″ E.

Description

Male (holotype)

CARAPACE ( Fig. 7a–c). Length 4.1 mm, height 2.5 mm. Coloration lightly yellowish-brown. 19 growth lines, 17 widely spaced and two crowded.

CARAPACE SHAPE. Dorsal margin straight, dorsoposterior corner rounded. Posterior margin broadly rounded, suboval, equicurvate (b/H 0.47). Ventral margin broadly rounded. Umbo position anterior (Cr/L 0.24).

CARAPACE ORNAMENTATION ( Fig. 7d–g). Larval valve and dorsal growth bands granular or punctate (under SEM clearly punctate). From mid-dorsal carapace, growth bands with strongly anastomosing and reticulating lirae, giving pit-like appearance. Reticulations elongate, more pronounced anteriorly and medially; posteriorly lirae subparallel and less reticulating but anastomosing. On ventral carapace, lirae short, pronounced and subparallel. Concentric ridges raised; smooth in early ontogenetic stages and with nodules in moniliform rows in later ontogenetic stages. Setae filiform, only few preserved (under SEM single row of setal pores along all growth lines).

HEAD ( Fig. 7h). Condyle long, distally acute, occipital notch narrow. Condyle with anterobasal hump. Margin between condyle and ocular tubercle concave. Ocular tubercle well developed, forming obtuse angle with rostrum. Anterior margin of rostrum convex, ventral margin straight, apex broadly rounded and obtuse. Naupliar eye triangular. Antenna I with eleven lobes, reaching to antenna II flagellomere V. Antenna II anterior ramus with twelve flagellomeres.

THORAX. 22 segments, 21 thoracopod-bearing and one limbless segment not reaching dorsal margin. Last twelve thoracopod-bearing segments with dorsal extensions bearing spines. Dorsal extensions increasing in size posteriorly over successive segments. Spines thin and elongate, central spines stronger and broader in posterior segments.

THORACOPOD III ( Fig. 7j). Endite I short and curved dorsally. Endites II–V broad, decreasing in size. Endite V two-segmented, basal segment shorter than endopod. Exopod ventral extension slightly overreaching endopod, dorsal extension slightly shorter than epipod. Epipod long, cylindric.

TELSON ( Fig. 7i). 15 spines. First spine (anterior) enlarged. Fourth spine enlarged, others subequal in length. First ten spines broad, conical, straight; subsequent five spines slender, elongate, aciculate and directed posteriorly. Last spines extend beyond terminal claw base. Terminal claw strongly curved, more strongly curved on right body half. Telson dorsal margin nearly straight, posteriorly concavely curved.

FURCA ( Fig. 7i). Proximally with dorsomedial longitudinal row of 9 setae, row ending distally in a single conical spine. Distal part ~⅔ of furca length, with numerous small denticles.

Female

Unknown.

Distribution ( Fig. 7k)

Currently known only from its type locality in central Queensland about 50 km S of Lake Galilee.

Remarks

Only a single male is known. The carapace shape of Ozestheria barcaldinensis sp. nov. ( Fig. 6) is distinct from most other species and is closely associated with O. minor comb. nov., O. setifera sp. nov., O. selmae sp. nov., O. cancellata comb. nov. and O. weeksi sp. nov.