Ozestheria cancellata ( Spencer & Hall, 1896 ), 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 : 35-41

Ozestheria cancellata ( Spencer & Hall, 1896) comb. nov.

Figs 12–13

Estheria packardi var. cancellata Spencer & Hall, 1896: 237–238 , figs 11–12.

Caenestheriella packardi var. cancellata – Daday 1914: 120–121.

Cyzicus packardi var. cancellata – Brtek 1997: 48.

Ozestheria packardi (in part) – Richter & Timms 2005: 347. — Rogers 2020: 24.

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

Diagnosis

Ozestheria cancellata comb. 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 prominent lirae forming ventrally within growth band, lirae become longer and more pronounced within progressing growth bands, lirae terminate in small nodule on concentric ridges (not visible in all specimens); male rostrum with straight to convex anterior margin, apex rounded with angle close to 90°, ventral margin with slight notch anteriorly and straight to weakly concave mid-length; female rostrum anterior margin straight (rarely weakly concave or weakly convex), apex rectangular (neither rounded nor drawn out), ventral margin nearly straight (only weakly concave); 10–15 (male) or 9–13 (female) antenna I lobes reaching to antenna II flagellomeres IV–IX (male) or II–V (female); 10–16 (male) or 11–16 (female) antenna II flagellomeres; 21–22 complete thorax segments; 12–24 small telsonic spines, anterior spines conical and equally spaced with 2–4 larger spines interspersed (usually in anterior half or two-thirds of telson), posterior spines slightly thinner, aciculate and slightly drawn out; 4–14 furcal setae.

Differential diagnosis

Ozestheria cancellata comb. 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. 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. 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. 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 long, elongated and aciculate. Ozestheria cancellata has more complete thorax segments (21–22) than O. typica , O. radiata , O. ngamurru , O. beleriandensis , O. glabra , O. weeksi , O. rincewindi , and O. bourkensis , but fewer than O. pilbarensis . The apex of the female rostrum of O. cancellata differs from that of O. marthae , O. weeksi and O. quinlanae by not being drawn out into a pointed tip. Ozestheria fuersichi differs by its polygonal reticulations on the first few growth bands and widely spaced, nodular lirae that disappear on crowded growth bands, the elongate and slender male rostrum and distinctly larger interspersed telsonic spines. Ozestheria barcaldinensis has fewer telsonic spines and the anterior margin of the male rostrum is more strongly convex and in O. jonnae the female anterior margin of the rostrum has a dorsal notch.

Type material

Neotype (here designated)

AUSTRALIA – Northern Territory • ♂; Old borrow pit 85 km N of Kulgera; 25°05′54.4″ S, 133°11′54.0″ E; 10 Mar. 2011, M. Schwentner and B.V. Timms leg.; GenBank no: KJ706023 ( COI); AM P.91796.

Other material examined

AUSTRALIA – New South Wales • 4 ♂♂; Muella Station, Upper Lake Eliza ; 29°25′46.0″ S, 145°04′12.6″ E; 31 Mar. 2009; M. Schwentner and B.V. Timms leg.; AM P.91784 to P91787 • 2 ♂♂, 1 ♀; Muella Station, Yantabulla black box swamp; 29°20′17.8″ S, 145°00′09.7″ E; 31 Mar. 2009; M. Schwentner and B.V. Timms leg.; AM P.91770 to P.91771 • 2 ♂♂, 2 ♀♀; Muella Station, Yantabulla black box swamp; 29°20′17.8″ S, 145°00′09.7″ E; 20 Jan. 2010; M. Schwentner and B.V. Timms leg.; AM P.91845 to P.91848 • 1 ♂; Tiltargara ; 31°51′09.9″ S, 144° 52′22.4″ E; 22 Jan. 2010; M. Schwentner and B.V. Timms leg.; raised later from sediment; AM P.91792 • 1 ♀; excavated area W of Yarrabundai ; 33°07′28.5″ S, 147°32′09.8″ E; 23 Jan. 2010; M. Schwentner and B.V. Timms leg.; AM P.91838 • 2 ♂♂, 3 ♀♀; thoura poplar box swamp; 29°16′11.2″ S, 144°40′25.3″ E; 24 Feb. 2011; M. Schwentner, S. Richter and B.V. Timms leg.; AM P.91829 to P.91833 . – Northern Territory • 1 ♂, 2 ♀♀; same data as for neotype; GenBank nos: KJ706021, KJ706024, KJ706025 ( COI); AM P.91794, P.91797, P.91798 • 1 ♀; same data as for neotype; GenBank no: KJ706022 ( COI); NHMW-ZOO-CR-28491 • 1 ♂, 1 ♀; south Henbury Crater ; 24°34′22.7″ S, 133°08′53.4″ E; 29 Mar. 2010; M. Schwentner and B.V. Timms leg.; raised later from sediment; AM P.91790, P.91791 • 1 ♂, 4 ♀♀; borrow pit next to Barrow Creek ; 21°29′14.2″ S, 133°54′49.0″ E; 7 Mar. 2011; M. Schwentner and B.V. Timms leg.; AM P.91799 to P.91803 . – South Australia • 1 ♀; borrow pit 90 km S of border; 26°49′22.0″ S, 133°19′44.7″ E; 10 Mar. 2011; M. Schwentner and B.V. Timms leg.; AM P.91804 • 1 ♂; dugout 55 km east of Marla ; 27°18′21.3″ S, 134°07′15.9″ E; 11 Mar. 2011; M. Schwentner and B.V. Timms leg.; AM P.91793 . – Queensland • 1 ♀; Thunda Lake ; 25°25′46.0″ S, 143°08′13.8″ E; 8 Apr. 2009; M. Schwentner and B.V. Timms leg.; raised later from sediment; AM P.91839 • 1 ♂; coolabah swamp, Cravens Peak (site M2); 23°22′04.7″ S, 138°35′53.5″ E; 16 Apr. 2007; J. Powling leg.; AM P.91850 • 3 ♂♂, 2 ♀♀; Currawinya National Park , quarry at boundary to national park; 28°59′49.9″ S, 144°12′01.9E; 26 Feb. 2011; M. Schwentner, S. Richter and B.V. Timms leg.; AM P.91819 to P.91823 • 4 ♂♂, 1 ♀; rocky quarry 83 km N of highway; 27°27′31.4″ S, 144°22′12.2″ E; 28 Feb. 2011; M. Schwentner and B.V. Timms leg.; AM P.91812 to P.91816 • 1 ♂, 1 ♀; dead shrub old borrow pit, 113 km S of Mount Isa ; 21°34′21.0″ S, 139°11′58.4″ E; 4 Mar. 2011; M. Schwentner and B.V. Timms leg.; AM P.91810, P.91811 • 1 ♂, 4 ♀♀; borrow pit, slightly turbid, 93 km S of Mount Isa ; 21°23′46.5″ S, 139°07′22.7″ E; 4 Mar. 2011; M. Schwentner and B.V. Timms leg.; AM P.91805 to P.91809 .

Additional material (not examined)

AUSTRALIA – New South Wales • 5 ♂♂; Muella Station, Muella Vegetated Pool 4; 29°30′00.7″ S, 144°54′59.6″ E; 31 Mar. 2009; M. Schwentner and B.V. Timms leg.; AM P.91775 to P.91779 • 2 ♂♂, 3 ♀♀; Muella Station, Lismore Bore ; 29°31′50.7″ S, 144°59′28.1″ E; 19 Jan. 2010; M. Schwentner and B.V. Timms leg.; AM P.82536, P.82536, P.91842 to P.91844 • 4 juvs; Muella Station, Lower Lake Eliza ; 29°25′28.9″ S, 145°03′41.8″ E; 22 Feb. 2011; M. Schwentner, S. Richter and B.V. Timms leg.; AM P.91834 to P.91837 • 3 ♂♂, 2 ♀♀; Muella Station, Carrols Bore ; 29°29′08.7″ S, 144°59′13.0″ E; 31 Mar. 2009; M. Schwentner and B.V. Timms leg.; AM P.80858, P.91780 to P.91783 • 4 juvs; Bloodwood Station, Pine Pool near Harolds Tank ; 29°22′25.2″ S, 144°49′12.6″ E; 8 Jun. 2007; B.V. Timms leg.; AM P.91851 to P.91854 • 1 juv.; Bloodwood Station , western fence N of Titanic; 29°24′58.4″ S, 144°46′52.8″ E; Mar. 2006; B.V. Timms leg.; AM P.91774 • 2 juvs; Yantabulla black box swamp; 29°20′17.8″ S, 145°00′09.7″ E; 20 Jan. 2010; M. Schwentner and B.V. Timms leg.; AM P.91769, P.91773 • 1 ♀; excavated area W of Yarrabundai ; 33°07′28.5″ S, 147°32′09.8″ E; 23 Jan. 2010; M. Schwentner and B.V. Timms leg.; AM P.91856 • 2 juvs; borrow pit, 30 km E of Bourke ; 30°19′00.5″ S, 146°06′58.4″ E; 10 Jun. 2007; B.V. Timms leg.; AM P.91840, P.91841 . – Queensland • 1 juv.; Rockwell Station, grassy pool S of N Blue Lake ; 28°50′53.8″ S, 144°57′47.3″ E; 9 Jun. 2007; B.V. Timms leg.; AM P.91855 • 2 juvs; Rockwell Station, Coolibah swamp; 28°54′03.2″ S, 144°59′22.6″ E; 1 Mar. 2009; M. Schwentner and B.V. Timms leg.; AM P.91788, P.91789 • 4 juvs; flood out of dam, 84 km S of Thargomindah ; 28°39′46.7″ S, 143°48′40.8″ E; 26 Feb. 2011; M. Schwentner and B.V. Timms leg.; AM P.91824 to P.91827 • 1 ♂, 1 ♀; dugout 21 km E of Thargomindah ; 28°02′05.2″ S, 144°03′15.7″ E; 27 Feb. 2011; M. Schwentner and B.V. Timms leg.; AM P.91817, P.91818 .

Type locality

Spencer & Hall (1896) did not specify a type locality but generally stated where they collected O. packardi and its newly described subspecies as “Common in water-holes along the Finke and its tributaries, also in the Macumba and Stevenson Rivers”. As the type material is lost and the exact locality unknown, we designated a neotype. The new type locality is: Australia, Northern Territory, old borrow pit 85 km N of Kulgera, 25°05′54.4″ S, 133°11′54.0″ E.

Description

Males ( Fig. 12a, c–d, i–j)

CARAPACE. Length 3.8–7.2 mm (NT: 4.4 mm, mean: 5.5 mm), height 2.2–4.7 (NT: 2.8 mm, mean: 3.4 mm). Coloration light to dark reddish-orange, outer margin lighter (yellow whitish). 21–60 (NT: 32, mean: 36) growth lines, 13–26 (NT: 18, mean: 19) widely spaced and 3–36 (HT: 14, mean: 17) crowded.

CARAPACE SHAPE. Dorsal margin straight, distinct dorso-posterior corner. Posterior margin broadly rounded, equicurvate (b/H 0.48–0.55, mean: 0.52). Ventral margin widely rounded. Umbo position anterior to submedian (Cr/L 0.21–0.29, mean: 0.26).

CARAPACE ORNAMENTATION ( Fig. 12e–h, k). Larval valve and following growth bands (approximately 1/8– ⅓ of carapace) granular (under SEM punctate with inconspicuous anastomosing fine lirae). In following growth bands more prominent lirae forming ventrally within growth bands between punctae, lirae initially shallow, hardly anastomosing. From about mid-carapace lirae distinct, subparallel, spanning full growth bands (under SEM, punctae gradually disappearing between lirae). Crowded growth bands with short, distinct lirae; lirae terminating in pronounced nodule on concentric ridges (not visible in all specimens, best visible under SEM). Concentric ridges slightly raised. Setae spiniform, preferentially preserved on the midposterior and posteroventral part of carapace; on outer margin of carapace sometimes filiform setae. Setal pores in single row along all growth lines.

HEAD ( Fig. 13a–c). Condyle long, distally rounded or elongated; occipital notch narrow. Condyle with weakly to strongly developed anterobasal hump. Margin between condyle and ocular tubercle straight to concave. Ocular tubercle weakly developed; forming obtuse (~120–170°) angle with rostrum. Small tubercle ventrally below eye in most specimens (HT: present). Anterior margin of rostrum straight to convex. Apex rounded, close to 90°. Ventral margin of rostrum with slight notch anteriorly, straight to weakly concave at midlength. Naupliar eye large and elongated, subtriangular to subrectangular (with rounded angles) or suboval. Antenna I long with 10–15 lobes (NT: 12; mean: 13), reaching to antenna II flagellomeres IV–IX (NT: VIII; mean: VII). Antenna II with 10–16 flagellomeres (HT: 13; mean: 13).

THORAX. 21–22 (HT: 22; mean: 22) segments, 21–22 (HT: 21; mean: 21) thoracopod-bearing and none to one (HT: one) posterior limbless segment not reaching dorsal margin. Dorsal extensions with numerous short setae, central setae usually longer; in posterior segments number of setae decreasing, becoming shorter and stouter.

THORACOPOD III (only P.91796). 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. 13f–g). 17–24 spines (NT: 18; mean: 19). First (anterior) spine enlarged. Spines small, conical, equally spaced, two to four larger spines interspersed (usually in anterior half or two-thirds of telson). Spines subequal in size, posterior-most spines slightly thinner, aciculate, slightly drawn out.

Anterior two-thirds of dorsal margin nearly straight, posteriorly slightly concave. Right terminal claw more strongly curved than left.

FURCA ( Fig. 13f–g). Proximally with dorsomedial longitudinal row of 5–14 (HT: 7; mean: 8) setae, row ending distally in a single conical spine. Distal part ½–¾ of furcal length, with numerous small denticles.

Females

Overall appearance as in males. Carapace ( Fig. 12b) length 3.7–6.4 mm (mean: 5.2 mm), height 2.3– 4.3 mm (mean: 3.3 mm); 18–52 (mean: 34) growth lines, of these 13–31 (mean: 22) widely spaced and 3–32 (mean: 12) crowded; Cr/L 0.21–0.29 (mean: 0.25) and b/H 0.48–0.56 (mean: 0.52). Ocular tubercle forming obtuse, nearly straight (~160–170°) angle with rostrum ( Fig. 13d). Anterior margin of rostrum usually straight, rarely weakly concave or weakly convex; rostrum apex rectangular (neither rounded nor drawn out); ventral margin nearly straight, only weakly concave. Antenna I with 9–13 small lobes (mean: 10), lobes smaller than in males; reaching to antenna II flagellomeres II–V (mean: III). Antenna II with 11–16 flagellomeres (mean: 13). 21–22 (mean: 22) segments, 21–22 (mean: 21) thoracopod-bearing and none to one posterior limbless segment not reaching dorsal margin. Telson with 12–24 (mean: 19) dorsal spines; left and right terminal claws equally curved or right stronger curved. Furca with 4–11 setae (mean: 6).

Distribution ( Fig. 13h)

Ozestheria cancellata comb. nov. is a common species and widely distributed across (semi)arid central and eastern Australia. It occurs in various waterbody types including black box swamps and was predominately found in artificial pools (e.g., borrow pits, dams or quarries).

Remarks

Ozestheria cancellata comb. nov. was originally described as one of three varieties of O. packardi by Spencer & Hall (1896). Previous workers (e.g., Richter & Timms 2005; Rogers 2020) have synonymized these varieties with O. packardi . However, the large cryptic species diversity, which was revealed by molecular genetic analyses within O. packardi ( Schwentner et al. 2015a) , strongly suggested that O. cancellata and the other varieties represent valid species. No type specimens are known of O. cancellata , and its original description is rather superficial and focuses exclusively on carapace features: length variables, number of growth bands, and ornamental features. Nevertheless, based on its several morphological similarities and the geographic distributions we are highly confident that of the many O. packardi -like species highlighted by Schwentner et al. (2015a), Ozestheria sp. S is conspecific with O. cancellata . Morphological similarities include foremost the conspicuous liral ornamentation in later ontogenetic stages; Spencer & Hall explicitly mentioned the pronounced nodules on concentric ridges arranged in a moniliform way, as well as the large number of growth lines (Spencer & Hall reported 30–50) and the spination of the telson (Spencer & Hall reported “spines of the telson are fewer in number than in var. typica and very irregular in shape and size”). The reported size difference between the specimens Spencer & Hall (1896) studied and the herein studied material most likely represents an age difference.

In the morphometric analyses of the carapace shape, the original drawing of O. cancellata comb. nov. by Spencer & Hall (1896) can be assigned to O. jonnae sp. nov. or O. cancellata (Supp. file 2_4.2). Also, O. cancellata is distinct from O. radiata sp. nov., O. typica comb. nov., O. bourkensis sp. nov., O. ngamurru sp. nov., O. beleriandensis sp. nov., O. carnegiensis sp. nov. but the species occupies a central position in the morphospace of Ozestheria and thus overlaps partly with numerous other species in the PCA ( O. jiangi sp. nov., O. minor comb. nov., O. fuersichi sp. nov., O. setifera sp. nov., O. sivesae sp. nov., O. timmsi sp. nov., O. frederikeae sp. nov., O. gemina sp. nov., O. jonnae , O. marthae sp. nov., O. selmae sp. nov., O. barcaldinensis sp. nov., O. weeksi sp. nov., O. quinlanae sp. nov., O. glabra sp. nov., O. echidna sp. nov., O. pilbarensis sp. nov.; Fig. 6).

To clarify the taxonomic status of O. cancellata comb. nov., it was deemed necessary to designate a neotype, in particular in the light of the many new described species, some of which are morphologically similar to O. cancellata , and the fact that the species had previously been synonymized with other species. There is no evidence that the original material collected by Spencer & Hall is preserved in any collection; requests to relevant collections yielded no such material. The original type locality was very poorly defined and a specimen from that region was selected as a neotype, which closely matches the original description by Spencer & Hall.