Ozestheria ngamurru, 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 : 101-104

Ozestheria ngamurru sp. nov.

urn:lsid:zoobank.org:act:AD8D90EC-8A18-4216-9FBC-26A5409008F5

Fig. 32

Diagnosis

Ozestheria ngamurru 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 concave anterior margin, apex protruding with distinct nearly rectangular angle, ventral margin with convex bulge midlength; 12–14 (male) antenna I lobes reaching to antenna II flagellomeres VII–IX (male); 13–14 (male) antenna II flagellomeres; 19–20 complete thorax segments; 27–30 telsonic spines, anterior spines conical, posterior spines elongate and aciculate; 7–9 furcal setae.

Differential diagnosis

Ozestheria ngamurru 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. barcaldinensis sp. nov., O. rincewindi 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 ngamurru sp. nov. differs from all these species in the shape of the male rostrum with its weakly concave anterior margin, weakly drawn-out apex and bulging ventral margin; moreover, O. ngamurru seems to have more widely spaced growth bands in the primary growth phase (21–27) than usually observed in these other species. Furthermore, O. 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 long, elongate and aciculate and O. fuersichi by its polygonal reticulations on the first few growth bands and punctae between widely spaced lirae.

Etymology

The name is derived from ngamurru, the traditional owner’s name for charcoal left in fire pits in the Martu language. The term is related to the Lake Carnegie area and has cultural significance, noun in apposition.

Type material

Holotype

AUSTRALIA – Western Australia • ♂; Lake Carnegie, Toonil Melaleuca Swamp ; 26°10′21.8″ S, 122°56′25.4″ E; 8 Jun. 2020; D.J. Cale leg.; WAM C78000 .

Paratypes

AUSTRALIA – Western Australia • 1 ♂; same data as for holotype; GenBank no: PQ427008 ( COI); WAM C80229 • 1 ♂; same data as for holotype; GenBank no: PQ427007 ( COI); NHMW-ZOO- CR-29002 .

Type locality

Western Australia, Lake Carnegie (Toonil Melaleuca Swamp), 26°10′21.8″ S, 122°56′25.4″ E.

Description

Males

CARAPACE ( Fig. 32a – c). Length 5.3–5.9 mm (HT: 5.9 mm), height 3.2–3.6 (HT: 3.6 mm). Coloration reddish-brown, crowded growth bands lighter. 53–58 (HT: 55) growth lines, 21–27 (HT: 27) widely spaced and 28–35 (HT: 28) crowded (the latter sometimes with widely spaced growth lines of secondary growth phase).

CARAPACE SHAPE. Dorsal margin straight to curved, dorso-posterior corner rounded. Posterior margin broadly rounded, suboval, equicurvate to infracurvate (b/H 0.51–0.57, HT: 0.51). Ventral margin rounded. Umbo position submedian (Cr/L 0.32–0.37, HT: 0.33).

CARAPACE ORNAMENTATION ( Fig. 32d–h). Larval valve and directly following growth bands punctate. In following growth bands, lirae forming between punctae; lirae becoming more pronounced and dominating with progressing growth bands. Lirae subparallel and ± equidistant on successive growth bands, not or very rarely anastomosing; from about mid carapace, punctae disappearing and lirae terminating in moniliform nodule on concentric ridge. Crowded growth bands and growth bands of secondary growth phase with short, parallel, distinct lirae all terminating in nodule on concentric ridges. Concentric ridges slightly raised, with moniliform nodules on the dorsal margin and an indistinct serrated ventral margin (best seen under SEM). Setae very short and spiniform (hardly visible); very few preserved, preferentially preserved on the ventral part of carapace (setal pores in single row along all growth lines under SEM).

HEAD ( Fig. 32i). Condyle long, elongated, distally rounded; occipital notch narrow. Condyle with small anterobasal hump. Margin between condyle and ocular tubercle straight to slightly concave. Ocular tubercle weakly developed, forming nearly straight angle with rostrum. Anterior margin of rostrum weakly concave, distally protruding. Apex weakly drawn out, with distinct nearly rectangular angle. Ventral margin of rostrum with convex bulge midlength. Naupliar eye subtriangular, rather large. Antenna I long with 12–14 lobes (HT: 13), reaching to antenna II flagellomeres VII–IX (HT: VII). Antenna II with 13–14 flagellomeres (HT: 14).

THORAX. 20 segments, 19–20 (HT: 19) thoracopod-bearing and none to one (HT: none) posterior limbless segment not reaching dorsal margin.

THORACOPOD III (only WAM C78000; Fig. 32k). 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 shorter in extension than endopod, dorsal extension wide, narrowing distally, overreaching epipod. Epipod long, cylindric.

TELSON ( Fig. 32j). 27–30 spines (HT: 30). First (anterior) spine enlarged. Spines on anterior half of telson wider and conical, following spines thinner, elongate and aciculate; all spines subequal in length and spacing. Dorsal margin straight or weakly concavely curved. Right terminal claw more strongly curved than left one.

FURCA ( Fig. 32j). Proximally with dorsomedial longitudinal row of 7–9 (HT: 8) setae, row ending distally in a single conical spine. Distal part ⅔–¾ of furcal length, with numerous small denticles.

Females

Unknown.

Distribution ( Fig. 32l)

Ozestheria ngamurru sp. nov. is known from a single locality in central Western Australia.

Remarks

Currently only males are known. Because only few specimens were available, the morphological variability of the species is not well characterized. The carapace shape of O. ngamurru sp. nov. ( Fig. 6) is distinct from that of most other species and overlaps fully with those of O. typica comb. nov. and marginally with O. radiata sp. nov. and O. beleriandensis sp. nov.