Eocyzicus ubiquus, Tippelt & Schwentner, 2018

Tippelt, Lisa & Schwentner, Martin, 2018, Taxonomic assessment of Australian Eocyzicus species (Crustacea: Branchiopoda: Spinicaudata), Zootaxa 4410 (3), pp. 401-452 : 413-417

Eocyzicus ubiquus sp. nov.

( Figs. 5 and 6 )

Eocyzicus lineage U Schwentner et al., 2014, 2015b

Etymology. The species name is derived from the Latin word "ubique", which means everywhere. This refers to the fact that this species occurs in a wide range of different aquatic habitats types (see also "Ecology").

Type locality. New South Wales, Murray-Darling Basin , Paroo River catchment, Bloodwood Station, Sues Pan, 29°29´05.6´´S, 144°48´38.0´´E.

Type material. Holotype. Male (AM P.89515, GenBank KC583880 ).

Allotype. Female (AM P.89517, GenBank KC583882 ).

Paratypes. 1 male (AM P.89515, GenBank KC583883 ), 2 females (AM P.89516, GenBank KC583881 ; AM P.89519, GenBank KC583884 ), collected by M. Schwentner, S. Richter and B. V. Timms, 21-II-2011.

Further material examined. New South Wales: 1 male (AM P.89491) Turbid pool, 29°32´29.3´´S, 146°24´50.1´´E, 21-I-2010 ; 1 male (AM P.89462) Vegetated pool 1, Muella Station , 29°31´10.3´´S, 144°56´21.8´´E, 31-III-2009 ; 1 male (AM P.89513) Lismore Bore, Muella Station , 29°31´50.7´´S, 144°59´28.1´´E, 19-I-2010 ; 1 male (AM P.89463), 1 female (AM P.89464) Yantabulla black box swamp, 29°20´18.0´´S, 145°00´12.1´´E, 31-III-2009 ; 1 female (AM P.89478) Black box swamp near Cumeroo , 29°15´41.2´´S, 145°09´29.0´´E, 20-I-2010 ; 1 male (AM P.89484) Gerara composite swamp, 29°11´47.0´´S, 146°17´03.0´´E, 21-I- 2010 ; 1 male (AM P.89501) Freshwater Lake, Bloodwood Station , 29°29´14.7´´S, 144°49´59.0´´E, 19-II-2010 ; 1 female (AM P.89470) Upper Crescent Pool, Bloodwood Station , 29°32´33.6´´S, 144°52´16.5´´E, 19-I-2010 ; 1 female (AM P.89461) East of Lake Lauradale, northwest of Bourke , 29°51´22´´S, 145°38´49´´E, 29-III-2009 ; Western Australia: 1 male (AM P.89514) Samphire swamp a few km south of Onslow , 21°43´S, 115°05´E, 14-III- 2009 ; Queensland: 1 male (AM P.89496) Cane grass swamp 75 km east of Wyandra , 27°23´03.5´´S, 146°36´33.7´´E, 17-II-2010 ; 1 male (AM P.89528), 1 female (AM P.89525) Old borrow pit 8 km east of Boulia , 22°55´44.6´´S, 139°58´23.7´´E, 0 4-III-2011 ; 1 female (AM P.89498) Grassy turbid swamp 10 km from Bollon Rd Junction , 27°41´52.4´´S, 146°45´44.7´´E, 18-II-2010 ; 1 female (AM P.89520) Floodout of Dam, 84km south of Thargomindah , 28°39´46.7´´S, 143°48´40.8´´E, 26-II-2011 .

Description. Holotype male. ( Fig. 5a, c and d ). Carapace. 5.0 mm high, 7.0 mm long, height/length ratio 0.64; height without "crowded" growth lines 4.1 mm; length without "crowded" growth lines 6.3 mm; shape oval; dorso-posterior corner clearly present; 21 growth lines, of these 19 "non-crowded" and two "crowded"; umbo large, hemispheric, growth lines on umbo present ( Fig. 5a ).

Head. Condyle rounded, section between condyle and external eye contour straight; eye bulge absent, compound eye round; straight angle between head and rostrum; anterior margin of rostrum straight, transition between anterior and ventral margin rounded ( Fig. 5c ). Antennule with 22 lobules, widely arranged; reaches to 10th antennary segment. Antenna with twelve antennary segments, middle antennary segment anteriorly with five spines.

Thorax. 20 thorax segments, of these 18 "complete" and two "incomplete" ( Fig. 5d ); dorsal spines beginning at 8th thorax segment, eleven thorax segments with dorsal spines; one dorsal spine at each thorax segment; first dorsal spine smaller than following one, last dorsal spine same size as the preceding one, last "complete" thorax segment with dorsal spine ( Fig. 5d ).

Telson. 13 telsonic spines, of these three enlarged, telsonic spines end at base of apex; telson symmetric; telsonic filaments situated at the third telsonic spine. Furca with 13 setae, longer than proximal part of furca; small spine before row of spinules present, spinules long ( Fig. 5d ).

Allotype female. ( Fig. 5b, e and f ). Carapace. 4.4 mm high, 6.8 mm long; height/length ratio 0.65; 18 growth lines, of these 16 "non-crowded" and two "crowded"; umbo small ( Fig. 5b ).

Head. Section between condyle and external eye contour concave; eye bulge small; transition between anterior and ventral margin of rostrum angular ( Fig. 5e ). Antennule reaches to fifth antennary segment. Antenna with middle antennary segment with four spines anteriorly.

Thorax. 22 thorax segments; of these 20 "complete" and two "incomplete" ( Fig. 5f ); dorsal spines beginning at 7th thorax segment, 13 thorax segments with dorsal spines; first dorsal spine same size as following one; last "complete" thorax segment without dorsal spine ( Fig. 5f ).

Telson. 16 telsonic spines, of these three enlarged, telsonic spines end after base of apex; telsonic filaments situated at fourth telsonic spine. Furca with five setae, as long as proximal part of furca ( Fig. 5f ).

Ovigerous flagella situated at 9th and 10th thorax segment.

Variability. Males Carapace. 3.1–5.1 mm high, 4.9–7.8 mm long, height/length ratio 0.63–0.68; height without "crowded" growth lines 2.5–5.1 mm; length without "crowded" growth lines 3.7–7.8 mm; dorso-posterior corner clearly present or nearly absent; 17–26 growth lines, of these 17–24 "non-crowded" and up to seven "crowded"; umbo small or large, cone-shaped or hemispheric, growth lines present or absent.

Head. Eye bulge absent or present, if present small or large, compound eye oval or round; obtuse to straight angle between head and rostrum; anterior margin of rostrum straight or convex, transition between anterior and ventral margin rounded or angular ( Fig. 6a ). Antennule with 15–25 lobules, closely or widely arranged; reaches to 8th –13th antennary segment. Antenna with 12–14 antennary segments, middle antennary segment anteriorly with four to seven spines ( Fig. 6b ).

Thorax. 20–21 thorax segments, of these 18–20 "complete" and one or two "incomplete" ( Fig. 6e ); dorsal spines beginning at 6th–10th thorax segment, 10–15 thorax segments with dorsal spines, last dorsal spine smaller than or same size as preceding one, last "complete" thorax segment with or without dorsal spine ( Fig. 6e ).

Telson. 11–15 telsonic spines, of these up to four enlarged, telsonic spines end before, at or after base of apex; telsonic filaments situated between the second and fifth telsonic spine. Furca with 3–14 setae, setae shorter than, as long as, or longer than proximal part of furca ( Fig. 6e ); small spine before row of spinules present or absent.

Variability. Females. Carapace. 3.2–5.2 mm high, 4.7–8.0 mm long, height/length ratio 0.63–0.68; height without "crowded" growth lines 3.0– 4.8 mm, length without "crowded" growth lines 4.5–7.3 mm; dorso-posterior corner clearly present or nearly absent; 12–24 growth lines, of these 11–21 "non-crowded" and up to seven "crowded"; umbo small or large, growth lines present or absent.

Head. Section between condyle and external eye contour concave or straight; eye bulge absent or present, if present small; acute or straight angle between head and rostrum, transition between anterior and ventral margin of rostrum rounded or angular. Antennule with 15–22 lobules, closely or widely arranged; reaches to 5th –7th antennary segment. Antenna with 11–14 antennary segments, middle antennary segment anteriorly with four to six spines.

Thorax. 20–22 thorax segments, 19–20 "complete" and one or two "incomplete"; dorsal spines beginning at 7th –10th thorax segment, 10–14 thorax segments with dorsal spines; first dorsal spine smaller than or same size as preceding one; last dorsal spine smaller than or same size as following one, last "complete" thorax segment with or without dorsal spine.

Telson. 12–18 telsonic spines, of these up to three enlarged, telsonic spines end before, at or after base of apex; telsonic filaments situated between second and sixth telsonic spine. Furca with two to twelve setae, shorter than or as long as proximal part of furca; small spine before row of spinules present or absent.

Differential diagnosis. Eocyzicus ubiquus sp. nov. is hard to distinguish from all other Eocyzicus species because of its large intraspecific variability that overlaps with that of many other species ( Table 1 and 2), especially with E. argillaquus ( Fig. 2a and c ). It is possible to differentiate these species morphologically by the total number of growth lines and of telsonic spines. Eocyzicus ubiquus sp. nov. and E. argillaquus are genetically clearly differentiated and not presumed sister species. Because of their sympatric distribution, they are certainly distinct species following the Biological Species Concept (Mayr, 1942), the Phylogenetic Species Concept sensu Wheeler & Platnick (2000), and the Evolutionary Species Concept (Wiley & Mayden, 2000). Eocyzicus ubiquus sp. nov. can be morphologically distinguished from its putative sister species E. timmsi sp. nov. by the number of growth lines and number of lobules on the antennules in females ( Tables 1 and 2).

Distribution and ecology. Eocyzicus ubiquus sp. nov. is distributed in a variety of water bodies with very different ecological conditions: in small pools as well as lakes, clear and turbid, fresh and hyposaline water bodies. It occurs sympatrically with Eocyzicus richteri sp. nov., E. phytophilus sp. nov., E. parvus sp. nov., E. argillaquus , E. parooensis , and E. armatus sp. nov. and rarely syntopically with the latter species.

Figures

FIGURE 2. Principal Components Analysis (PCA) and Cannonical Variates Analysis (CVA). In the CVA specimens are assigned to species prior to analysis, whereas no such assignment is done in the PCA. a, PCA of males. b, CVA of males. c, PCA of females. d, CVA of females. Each square corresponds to one individual.Bold arrows indicate the single individuals of E.occidentalissp.nov and E.careyensis sp. nov., respectively.Axeswith most importantcharacters are displayed inlight grey.

FIGURE 5. Eocyzicus ubiquus sp. nov. a, carapace of male holotype (AM P.89515). b, carapace of female allotype (AM P.89517). c, head of male holotype. d, telson of male holotype. e, head of female allotype. f, telson of female allotype. ce = compound eye, co = condylus, ds = dorsal spine, fu = furca, gl = growth lines, is = „incomplete" thorax segments, md = mandible, ro = rostrum, sp = spinules, tf = telsonicfilaments, ts = telsonic spines, um = umbo.

FIGURE 6. Eocyzicus ubiquus sp. nov. male paratype (AM P.89518). a, rostrum (left antenna removed). b, fifth and sixth segment of theleft antenna.c,first orsecond right clasper, arrowindicates the scales at the tipof the movable finger.d, detail of the tipof themovable finger of first or second right clasper.e, telson, arrows indicate "incomplete" thorax segments. f, detail of distal part of furca. A1 = antennules, ds = dorsal spine, fu = furca, lp = large palpus, mf = movable finger, ro = rostrum, sc = scales, sp = spinules, tf = telsonic filaments, ts = telsonic spines.