Eocyzicus parvus,

Tippelt, Lisa & Schwentner, Martin, 2018, Taxonomic assessment of Australian Eocyzicus species (Crustacea: Branchiopoda: Spinicaudata), Zootaxa 4410 (3), pp. 401-452: 430-433

publication ID

https://doi.org/10.11646/zootaxa.4410.3.1

publication LSID

lsid:zoobank.org:pub:F81EF784-209A-4933-932D-0A507BA85E2B

persistent identifier

http://treatment.plazi.org/id/039FB973-FFEA-9115-A180-FC34C0A6FDCD

treatment provided by

Plazi

scientific name

Eocyzicus parvus
status

sp. nov.

Eocyzicus parvus  sp. nov.

( Figs. 15View FIGURE 15 and 16View FIGURE 16)

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

Etymology. The Latin word " parvus  " means small and refers to the size of the carapace, which is smaller than in other Australian Eocyzicus  species (see Tables 1 and 2).

Type locality. Queensland, Bulloo River catchment, roadside dugout with yellow lilies, 27°58´26.8´´S, 144°18´34.9´´E.GoogleMaps 

Type material. Holotype. Male (AM P.91862, no GenBank number).

Allotype. Female (AM P.89457, GenBank KC583822).

Paratypes. 1 male (AM P.89456, GenBank KC583821), 3 females (AM P.89454, GenBank KC583819; AM P.89455, GenBank KC583820; AM P.89458, GenBank KC583823), collected by M. Schwentner, S. Richter and B. V. Timms, 27-II-2011.

Further material examined: no material from other localities available

Description: Holotype male ( Fig. 15 a, c and dView FIGURE 15). Carapace. 2.5 mm high, 4.0 mm long, height/length ratio 0.63; height without "crowded" growth lines 2.5 mm, length without "crowded" growth lines 4.0 mm; shape oval; dorso-posterior corner clearly present; nine growth lines, all "non-crowded"; umbo small; hemispheric, growth lines absent ( Fig. 15aView FIGURE 15).

Head. Condyle rounded, section between condyle and external eye contour straight; eye bulge absent, compound eye oval; acute angle between head and rostrum; anterior margin of rostrum straight, transition between anterior and ventral margin angular ( Fig. 15cView FIGURE 15). Antennule with 17 lobules, widely arranged; reaches to 9th antennary segment. Antenna with ten antennary segments, middle antennary segment anteriorly with two spines.

Thorax. 21 thorax segments, of these 19 "complete" and two "incomplete" ( Fig. 15dView FIGURE 15); dorsal spines beginning at 7th thorax segment, thirteen 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 with dorsal spine ( Fig. 15dView FIGURE 15).

Telson. 14 telsonic spines, of these two enlarged; telsonic spines end at base of apex; telson symmetric; telsonic filaments situated between third and fourth telsonic spine. Furca with five setae, longer than proximal part of furca; small spine before row of spinules present, spinules short ( Fig. 15dView FIGURE 15).

Allotype female ( Fig. 15b, e and fView FIGURE 15). Carapace. 2.8 mm high, 4.2 mm long, height/length ratio 0.67; height without "crowded" growth lines 2.8 mm; length without "crowded" growth lines 4.2 mm; dorso-posterior corner nearly absent ( Fig. 15bView FIGURE 15).

Head. Compound eye round; right angle between head and rostrum; anterior margin of rostrum convex, transition between anterior and ventral margin of rostrum rounded ( Fig. 15eView FIGURE 15). Antennule with 20 lobules, closely arranged; reaches to 7th antennary segment. Antenna with eleven antennary segments, middle antennary segment anteriorly with five spines.

Thorax. 13 thorax segments with dorsal spines.

Telson. 16 telsonic spines, of these three enlarged. Furca with two setae, shorter than proximal part of furca ( Fig. 15fView FIGURE 15).

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

Variability. Males. Carapace. 3.7–4.0 mm long, height/length ratio 0.63–0.68; length without "crowded" growth lines 3.7–4.0 mm long; dorso-posterior corner clearly present or nearly absent.

Head. Compound eye oval or round; anterior margin of rostrum straight or convex; transition between anterior and ventral margin rounded or angular. Antennule with 15–17 lobules, closely or widely arranged; reaches to 8th or 9th antennary segment. Antenna with middle antennary segment anteriorly with two or four spines.

Thorax. 21 or 22 thorax segments, of these 19 or 20 "complete" and two "incomplete"; dorsal spines beginning at 7th or 9th thorax segment; eleven or thirteen thorax segments with dorsal spines, last "complete" thorax segment with or without dorsal spine.

Telson. 14 or 16 telsonic spines, of these two or three enlarged. Furca with four or five setae, as long as or longer than proximal part of furca; small spine before row of spinules present or absent.

Variability. Females. Carapace. 2.3–2.8 mm high, 3.3–4.2 mm long, height/length ratio 0.67–0.73; height without "crowded" growth lines 2.3–2.8 mm, length without "crowded" growth lines 3.3–4.2 mm; dorso-posterior corner clearly present or nearly absent; eight or nine growth lines, all "non-crowded".

Head. Compound eye oval or round; acute to obtuse angle between head and rostrum; anterior margin of rostrum straight or convex, transition between anterior and ventral margin rounded or angular ( Fig. 16aView FIGURE 16). Antennule with 17–20 lobules, reaches to 5th –8th antennary segment. Antenna with ten or eleven antennary segments ( Fig. 16cView FIGURE 16), middle antennary segment anteriorly with four or five spines ( Fig. 16dView FIGURE 16).

Thorax. 19–22 thorax segments, of these 18–20 "complete" and one or two "incomplete" ( Fig. 16bView FIGURE 16); dorsal spines beginning at 6th –8th thorax segment, 12 or 13 thorax segments with dorsal spines; last dorsal spine smaller or same size as preceding one.

Telson. 12–16 telsonic spines, of these two to four enlarged, telsonic spines end before or at base of apex; telsonic filaments situated between the second and fourth telsonic spine. Furca with two to five setae, shorter than, as long as or longer than proximal part of furca ( Fig. 16bView FIGURE 16).

Differential diagnosis. Eocyzicus parvus  sp. nov. can be morphologically clearly differentiated from all other Australian Eocyzicus  species by its size, the small number of growth lines and the number of setae on the furca. No egg bearing females were among the examined individuals. Thus, it is possible that the studied individuals are not fully matured. The morphologic and genetic differentiation from its putative sister species E. phytophilus  sp. nov. (with which it occurs sympatrically) support its species status based on the PSC sensu Wheeler & Platnick (2000), the ESC (Wiley & Mayden, 2000) and the BSC (Mayr, 1942).

Distribution and ecology. The only locality from which Eocyzicus parvus  sp. nov. is known is a fresh and clear pool with yellow lilies. This species occurs sympatrically with Eocyzicus ubiquus  sp. nov., E. phytophilus  sp. nov. and E. argillaquus  .

BSC

Centro Oriental de Ecosistemas y Biodiversidad