Ozestheria beleriandensis, 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 : 23-26

Ozestheria beleriandensis sp. nov.

urn:lsid:zoobank.org:act:5562280D-059B-4179-91EB-A205B1A67AE9

Fig. 8

Diagnosis

Ozestheria beleriandensis 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 anastomosing lirae forming ventrally within growth band, lirae become longer, less anastomosing and more pronounced with progressing growth bands, lirae terminate in nodule; male rostrum with weakly undulating or straight anterior margin, apex pointed (not rounded) and acute (~70°–80°), ventral margin weakly concave, rarely with anterior notch; female rostrum with weakly concave (slightly undulating or nearly straight) anterior margin, apex rectangular and weakly drawn out into acute tip, ventral margin straight or weakly convex; 12–16 (male) or 10–12 (female) antenna I lobes reaching to antenna II flagellomeres VII–IX (male) or IV–V (female); 12–14 (male) or 12 (female) antenna II flagellomeres; 19–20 complete thorax segments; 23–34 telsonic spines, anterior spines small and conical with usually one larger spine interspersed, posterior spines elongate, aciculated and increasing in size posteriorly; 7–11 furcal setae.

Differential diagnosis

Ozestheria beleriandensis sp. nov. can be differentiated from many other species of Ozestheria by its 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. jonnae sp. nov., O. marthae sp. nov., O. selmae sp. nov., O. radiata sp. nov., O. rincewindi sp. nov., O. barcaldinensis sp. nov., O. ngamurru sp. nov., O. bourkensis 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 beleriandensis differs from O. cancellata , O. fuersichi , O. jonnae , O. marthae , O. rincewindi , O. barcaldinensis , O. ngamurru , O. quinlanae , O. glabra , O. pilbarensis and O. weeksi by having at least the posterior half of telsonic spines long, elongated and aciculate (in the other species fewer telsonic spines are long and aciculate and more spines shorter and conical) and by the shape of the female rostrum (weakly concave anterior margin and apex drawn out into a pointed tip). Ozestheria typica and O. bourkensis have smaller carapace sizes and of the male rostrum the anterior margin is more strongly concave and the apex rounded. In O. minor the apex of the male rostrum has a slightly more acute angle and is often more strongly extending and pointing downwards, and O. beleriandensis has a more pronounced larger spine midlength on the telson. Ozestheria selmae sp. nov. has usually more complete thorax segments (20–22 vs 19–20) and the anterior margin of the female rostrum is more strongly concave and slightly undulating. Ozestheria radiata sp. nov. has a straighter ventral carapace margin, a more strongly developed ocular tubercle and the apex of the male rostrum is rounded.

Etymology

The species name derives from the mythical Beleriand, which was a region in the West of J.R.R. Tolkien’s Middle-earth. Ozestheria beleriandensis is known from Western Australia.

Type material

Holotype

AUSTRALIA – Western Australia • 1 ♂; Lake Carnegie (Windidda 2); 26°15′52.7″ S, 122°16′29.23″ E; 4 Jun. 2020; D.J. Cale leg.; GenBank no: PQ427012 ( COI); WAM C77999 .

Paratypes

AUSTRALIA – Western Australia • 1 ♂, 2 ♀♀; same data as for holotype; GenBank nos: PQ427011 ( COI); WAM C80222 to C80224 • 1 ♂; same data as for holotype; NHMW-ZOO-CR-28499 .

Other material examined

AUSTRALIA – Western Australia • 4 ♂♂, 1 ♀; pool on Ex-Earaheedy Station , 200 km NE of Wiluna; 25°36′13.1″ S, 121°28′29.7″ E; 6 Feb. 2012; B.V. Timms leg.; WAM C77998 , WAM C80218 to C80221 .

Type locality

Western Australia, Lake Carnegie (Windidda 2), 26°15′52.7″ S, 122°16′29.23″ E.

Description

Males

CARAPACE ( Fig. 8a, c–d). Length 5.0– 5.7 mm (HT: 5.7 mm), height 3.0–3.5 (HT: 3.5 mm). Coloration red-orange to brown, crowded growth bands lighter. 42–68 (HT: 68) growth lines, 14–32 (HT: 16) widely spaced and 10–54 (HT: 52) crowded; some individuals with secondary growth phase.

CARAPACE SHAPE. Dorsal margin straight, distinct or rounded dorsoposterior corner. Posterior margin broadly rounded, suboval, equicurvate (b/H 0.51–0.55, HT: 0.53). Ventral margin widely rounded. Umbo position submedian (Cr/L 0.30–0.32, HT: 0.32).

CARAPACE ORNAMENTATION ( Fig. 8e–g). Larval valve and directly following growth bands punctate. In following growth bands, shallow and anastomosing lirae forming between punctae; lirae becoming more pronounced, subparallel and dominating with progressing growth bands; from about mid carapace, lirae terminating in nodules on concentric ridges in moniliform row. Crowded growth bands with short, parallel, distinct lirae all terminating in nodule, if crowded growth bands too densely spaced only nodules visible and no lirae. Concentric ridges slightly raised, with moniliform nodules on the dorsal margin. Setae filiform, preferentially preserved on the midposterior and posteroventral part of carapace (setal pores in single row along all growth lines under SEM).

HEAD ( Fig. 8j). Condyle long, distally acute, occipital notch narrow. Condyle with weak or without anterobasal hump (HT: absent). Margin between condyle and ocular tubercle slightly convex to straight. Ocular tubercle weakly developed, forming obtuse (~150°) to nearly straight angle with rostrum.Anterior margin of rostrum weakly undulating or straight (HT: undulating). Apex pointed (not rounded) and acute (~70–80°), in some individuals pointing downwards. Ventral margin of rostrum weakly concave, rarely with anterior notch. Naupliar eye subtriangular. Antenna I long with 12–16 lobes (HT: 14), reaching to antenna II flagellomeres VII–IX (HT: IX). Antenna II with 12–14 flagellomeres (HT: 14).

THORAX. 19–20 segments (HT: 29), 19–20 (HT: 19) thoracopod-bearing and 1–0 (HT: 1) posterior limbless segment not reaching dorsal margin. Most thoracopod-bearing segments with dorsal extension bearing numerous short and stout spines.

THORACOPOD III (only WAM C77999; Fig. 8m). 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 in extension to endopod, dorsal extension wide, narrowing distally, overreaching epipod. Epipod long, cylindric.

TELSON ( Fig. 8l). 23–34 spines (HT: 26). First (anterior) spine enlarged. Spines on anterior ¼–½ of telson short, thin, conical, subequal in length; following spines increasing in size, becoming thinner, longer, aciculate and more closely spaced; usually one larger spine interspersed between smaller spines. Telson dorsal margin straight or concave. Right terminal claw more strongly curved than left.

FURCA ( Fig. 8l). Proximally with dorsomedial longitudinal row of 8–9 (HT: 9) 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. 8b) length 5.4–5.6 mm, height 3.4–3.5 mm; 46–60 growth lines, 14–25 widely spaced and 15–46 crowded (some individuals with secondary growth phase); Cr/L 0.30–0.32 and b/H 0.51–0.53. Angle between head and rostrum nearly rectangular. Rostrum ( Fig. 8k) anterior margin weakly concave (slightly undulating or nearly straight); apex rectangular, pointed and weakly drawn out into acute tip; ventral margin straight or weakly convex. Antenna I with 10–12 small lobes, lobes smaller than in males; reaching to antenna II flagellomeres IV–V. Antenna II with 12 flagellomeres. Telson with 28–29 dorsal spines; left and right terminal claws equally curved or right slightly stronger curved. Furca with 7–11 setae.

Distribution ( Fig. 8n)

Ozestheria beleriandensis sp. nov. is known from two localities in central Western Australia.

Remarks

The carapace shape of Ozestheria beleriandensis sp. nov. ( Fig. 6) is distinct from that of most other species and overlaps with O. minor comb. nov., O. selmae sp. nov., O. radiata sp. nov. (marginally), O. typica comb. nov., O. ngamurru sp. nov. (marginally) and O. carnegiensis sp. nov.