Eocyzicus careyensis, Tippelt & Schwentner, 2018

Tippelt, Lisa & Schwentner, Martin, 2018, Taxonomic assessment of Australian Eocyzicus species (Crustacea: Branchiopoda: Spinicaudata), Zootaxa 4410 (3), pp. 401-452 : 438

Eocyzicus careyensis sp. nov.

( Fig. 19 c, d and e )

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

Etymology. " Careyensis" refers to Lake Carey, which is the only known locality for this species. The species name means "lives in Lake Carey".

Type locality. Western Australia, Lake Carey , 29°10´S, 122°20´E.

Type material. Holotype. Female (Western Australian Museum registration number 55044, GenBank KC583813 ), collected by B. V. Timms, 08-III-2011.

Further material examined. No material from other localities available

Description. Holotype female ( Fig. 19 c, d and e ). Carapace. 5.0 mm high, 8.5 mm long, height/length ratio 0.59; height without "crowded" growth lines 4.7 mm, length without "crowded" growth lines 8.0 mm; shape oval; dorso-posterior corner nearly absent; 13 growth lines, of these twelve "non-crowded" and one "crowded"; umbo small, hemispheric, growth lines present ( Fig. 19c ).

Head. Condyle rounded; section between condyle and external eye contour concave; eye bulge small, compound eye oval; straight angle between head and rostrum; anterior margin of rostrum straight; transition between anterior and ventral margin angular ( Fig. 19d ). Antennule with twelve lobules, widely arranged; reaches to third antennary segments. Antenna with twelve antennary segments, middle antennary segment anteriorly with two spines.

Thorax. 23 thorax segments, of these 21 "complete" and two "incomplete" ( Fig. 19e ); dorsal spines beginning at 13th thorax segment, eight thorax segments with dorsal spines; one dorsal spine at each thorax segment, first dorsal spine smaller than following one, last dorsal spine smaller than preceding one, last "complete" thorax segment without dorsal spine ( Fig. 19 e ).

Telson. 20 telsonic spines, of these three enlarged, telsonic spines end after base of apex; telson symmetric; telsonic filaments situated between third and fourth telsonic spine. Furca with 22 setae, longer than proximal part of furca; small spine before row of spinules absent, spinules short ( Fig. 19e ).

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

Differential diagnosis. According to Schwentner et al. (2014) the putative sister species are Eocyzicus armatus sp. nov. and E. parooensis . The PCA showed a clear differentiation between E. careyensis sp. nov. and these two as well as all other species ( Fig. 2c ). Eocyzicus careyensis sp. nov. can be morphologically differentiated from E. armatus sp. nov. and E. parooensis by the number of all growth lines, number of lobules on the antennules, number of thorax segments with dorsal spines and number of setae on the furca ( Table 2). Eocyzicus armatus sp. nov. can be delimited following the PSC (Wheeler & Platnick, 2000) and the ESC (Wiley & Mayden, 2000). However, it does not occur in sympatry with any other Eocyzicus species and, therefore, its species status following the BSC (Mayr, 1942) remains ambiguous.

Distribution and ecology. This species is known only from Lake Carey, a large clear hyposaline lake. Eocyzicus careyensis sp. nov. does not occur sympatrically with any other studied Eocyzicus 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 19. Eocyzicus occidentalis sp. nov. and E. careyensis sp. nov. a–b, E. occidentalis sp. nov. (AM P.89447). a, carapace of male holotype. b, head of male holotype (telson is not shown due to severe damage). c–e, E. careyensis sp. nov. (AM P.89448).c, carapace of femaleholotype.d, head of female holotype.e,telson of female holotype.ce = compound eye,co = condylus, ds = dorsal spine,fu = furca, gl= growth lines, is = „incomplete" thoraxsegments, md = mandible,ro = rostrum, sp = spinules, tf = telsonic filaments, ts = telsonic spines, um = umbo.