Eocyzicus parooensis Richter & Timms, 2005

Tippelt, Lisa & Schwentner, Martin, 2018, Taxonomic assessment of Australian Eocyzicus species (Crustacea: Branchiopoda: Spinicaudata), Zootaxa 4410 (3), pp. 401-452 : 440-441

Eocyzicus parooensis Richter & Timms, 2005

Eocyzicus sp. a Timms & Richter 2002

Eocyzicus parooensis Richter & Timms, 2005 ; Timms & Richter, 2009; Schwentner et al., 2009; Schwentner et al., 2014, 2015b

Material examined. New South Wales: 2 males (AM P.89430, AM P.89433), 3 females (AM P.89431, AM P.89432, AM P.89434) Gidgee Lake, Bloodwood Station, 29°33´10.4´´S, 144°50´12.7´´E, 19-II-2010 ; 4 males (AM P.89442, AM P.89443, AM P.89444, AM P.89445), 2 females (AM P.89441, AM P.89446,) Woolshed Salt Lake , Bloodwood Station, 29°31´44.3´´S, 144°51´11.1´´E, 19-II-2010 ; 3 males (AM P.89435, AM P.89439, AM P.89440), 3 females (AM P.89436, AM P.89437, AM P.89438) Horseshoe Lake , Bloodwood Station, 29°31´32.2´´S, 144°45´57.8´´E, 19-II-2010 .

Variability. Males. Carapace. 4.9–5.9 mm high, 8.1–9.4 mm long, height/length ratio 0.59–0.64; height without "crowded" growth lines 4.5–5.9 mm, length without "crowded" growth lines 7.3–9.4 mm; dorso-posterior corner clearly present or nearly absent; 14–20 growth lines, of these 12–17 "non-crowded" and up to four "crowded"; umbo small or large, cone-shaped or hemispheric.

Head. Compound eye oval or round; acute to right angle between head and rostrum. Antennule with 16–18 lobules, closely or widely arranged; reaches to 6th –9th antennary segment. Antenna with 11–13 antennary segments, middle antennary segment anteriorly with five to eight spines.

Thorax. 23 thorax segments, of these 21–22 "complete" and one or two "incomplete"; dorsal spines beginning at 7th –10th thorax segment, 11–15 thorax segments with dorsal spines; first dorsal spine smaller than or same size as following one, last dorsal spine smaller than or same size as preceding one, last "complete" thorax segment with or without dorsal spine.

Telson. 9–15 telsonic spines, of these one to five enlarged, telsonic spines end before, at or after base of apex; telson symmetric; telsonic filaments situated between the second and sixth telsonic spine. Furca with 12–26 setae.

Variability. Females. Carapace. 4.1–5.6 mm high, 6.8–8.6 mm long, height/length ratio 0.6–0.65; height without "crowded" growth lines 3.9–5.2 mm, length without "crowded" growth lines 6.0– 8.2 mm; dorso-posterior corner clearly present or nearly absent; 14–20 growth lines, of these 11–18 "non-crowded" and one to five "crowded".

Head. Eye bulge small or large, compound eye oval or round; acute to obtuse angle between head and rostrum; transition between anterior and ventral margin of rostrum rounded or angular. Antennule with 13–19 lobules, closely or widely arranged; reaches to fourth to sixth antennary segment. Antenna with 11–13 antennary segments, middle antennary segment anteriorly with five to seven spines.

Thorax. 22–24 thorax segments, of these 20–22 "complete" and two "incomplete" thorax segments; dorsal spines beginning at 6th–13th thorax segment, 9–16 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.

Telson. 16–32 telsonic spines, of these three to six enlarged, telsonic spines end before, at or after base of apex; telson symmetric; telsonic filaments situated between 4th and 10th telsonic spine. Furca with 12–23 setae.

Differential diagnosis. This species resembles morphologically its two putative sister species E. armatus sp. nov and E. careyensis sp. nov. Eocyzicus parooensis can be distinguished from them by the number of all growth lines on the carapace, number of lobules on the antennules, number of thorax segments with dorsal spines and number of setae on the furca ( Tables 1 and 2, Fig. 2 ).

In the original description of E. parooensis only material from the species’ type locality was included (Richter & Timms, 2005). Conversely, the much larger morphological variability described by Timms & Richter (2009) included specimens from localities, which are inhabited by other species (e.g., E. ubiquus sp. nov. and E. armatus sp. nov.) resulting in overestimations of the species’ morphological variability.

Distribution and ecology. Eocyzicus parooensis occurs exclusively in a few hyposaline, mostly clear water bodies in the central Paroo River catchment and is sympatrically distributed with E. ubiquus sp. nov., E. richteri sp. nov., E. phytophilus sp. nov., E. armatus sp. nov. and E. argillaquus .

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.