Eocyzicus richteri,

Tippelt, Lisa & Schwentner, Martin, 2018, Taxonomic assessment of Australian Eocyzicus species (Crustacea: Branchiopoda: Spinicaudata), Zootaxa 4410 (3), pp. 401-452: 420-424

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-FFE4-9122-A180-FA1DC295FD59

treatment provided by

Plazi

scientific name

Eocyzicus richteri
status

sp. nov.

Eocyzicus richteri  sp. nov.

( Figs. 9View FIGURE 9 and 10View FIGURE 10)

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

Etymology. The species is named in honor of Prof. Stefan Richter (University of Rostock). The work of Prof. Richter has significantly contributed to further our understanding of the evolution of Branchiopoda, which includes the first descriptions of Australian Eocyzicus  species. In addition, he mentored and supported both authors of the present study, for which we are very thankful.

Type locality. Queensland, Currawinya National Park, turbid claypan South of North Kaponyee , 28°49´27.4´´S, 144°19´44.5´´E.GoogleMaps 

Type material. Holotype. Male (AM P.89626, GenBank KC583987).

Allotype. Female (AM P.89623, GenBank KC583984).

Paratypes. 3 males (AM P.89624, GenBank KC583985; AM P.89625, GenBank KC583986; AM P.89627, GenBank KC583988), collected by M. Schwentner, S. Richter and B. V. Timms, 24-II-2011.

Further material examined. New South Wales: 1 male (AM P.89620) Island claypan, Bloodwood Station, ca. 500m east of Freshwater Lake , 29° 29´S, 144° 50´E), 28-IX-2010GoogleMaps  ; Queensland: 1 male (AM P.89615) Rockwell Station, Big Kangaroo Pan , 28° 57´S, 144° 58´E, 1999GoogleMaps  ; 1 female (AM P.89617) Lower Lake Eliza, Muella Station , 29°25´28.9´´S, 145°03´41.8´´E, 20-II-2010GoogleMaps  ; 1 male (AM P.89634) Claypan halfway on northern Fence of Bilby Pen, Currawinya National Park, 28°52´12.8´´S, 144°21´52.1´´E, 25-II-2011GoogleMaps  ; 1 male (AM P.89630), 1 female (AM P.89629) Triops claypan, Currawinya National Park , 28°47´14.9´´S, 144°17´49.1´´E, 24-II-2011GoogleMaps  ; 1 female (AM P.89631) Vegetated Island Claypan, Currawinya National Park, 28°47´14.0´´S, 144°17´45.7´´E, 24-II-2011GoogleMaps  ; 1 female (AM P.89633) Claypan at old Wyara Junction, Currawinya National Park, 28°47´49.4´´S, 144°17´55.6´´E, 24-II-2011GoogleMaps  ; South Australia: 1 male (AM P.89644)  , 4 females (AM P.89642, AM P.89643, AM P.89645, AM P.89646) Stony claypan, 20 km north of Williams Creek , 28°51´30.1´´S, 136°09´49.1´´E, 12-III-2011GoogleMaps  ; 1 male (AM P.89641), 1 female (AM P.89640) Cane grass swamp 26 km north of Oodnadatta , 27°24´18.0´´S, 135°21´00.1´´E, 11-III-2011GoogleMaps  ; 1 male (AM P.89637) Cane grass swamp, 44 km west of Oodnadatta , 27°20´07.1´´S, 135°07´47.7´´E, 11-III-2011GoogleMaps  .

Description. Holotype male ( Fig. 9 a, c and dView FIGURE 9). Carapace. 3.5 mm high, 5.4 mm long, height/length ratio 0.65; height without "crowded" growth lines 3.3 mm; length without "crowded" growth lines 5.0 mm; shape oval; dorso-posterior corner nearly absent; 20 growth lines, of these 18 "non-crowded" and two "crowded"; umbo large, hemispheric, growth lines present ( Fig. 9aView FIGURE 9).

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. 9cView FIGURE 9). Antennule with 27 lobules, closely arranged; reaches to 11th antennary segment. Antenna with 13 antennary segments, middle antennary segment anteriorly with three spines.

Thorax. 20 thorax segments, of these 18 "complete" and two "incomplete" ( Fig. 9dView FIGURE 9); dorsal spines beginning at 11th thorax segment, eight thorax segments with dorsal spines; one dorsal spine at each thorax segment, first dorsal spine same size as following one; last dorsal spine smaller than preceding one, last "complete" thorax segment with dorsal spine ( Fig. 9dView FIGURE 9).

Telson. 16 telsonic spines, of these one enlarged, telsonic spines end after base of apex; telson symmetric; telsonic filaments situated between fourth and fifth telsonic spine. Furca with five setae, shorter than proximal part of furca; small spine before row of spinules present, spinules short ( Fig. 9dView FIGURE 9).

Allotype female ( Fig. 9b, e and fView FIGURE 9). Carapace. 4.6 mm high, 6.4 mm long; height/length ratio 0.72; height without "crowded" growth lines 4.5 mm; length without "crowded" growth lines 6.2 mm; 21 growth lines, of these 20 "non-crowded" and one "crowded"; umbo cone-shaped ( Fig. 9bView FIGURE 9).

Head. Section between condyle and external eye contour concave; eye bulge small; right angle between head and rostrum ( Fig. 9eView FIGURE 9). Antennule with 17 lobules; reaches to sixth antennary segment. Antenna with middle antennary segment anteriorly with six spines.

Thorax. Dorsal spines beginning at 8th thorax segment, eleven thorax segments with dorsal spines; first dorsal spine smaller than following one.

Telson. 18 telsonic spines without enlarged, telsonic spines end at the base of apex; telsonic filaments situated between the 5th and 6th telsonic spine. Furca with two setae ( Fig. 9fView FIGURE 9).

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

Variability. Males. Carapace. 2.9–5.0 mm high, 4.6–8.0 mm long, height/length ratio 0.59–0.69; height without "crowded" growth lines 2.2–4.7 mm, length without "crowded" growth lines 3.4–7.0 mm; dorso-posterior corner clearly present or nearly absent; 17–34 growth lines, of these 12–26 "non-crowded" and up to eight "crowded"; umbo small or large, cone-shaped or hemispheric.

Head. Section between condyle and external eye contour concave or straight; eye bulge absent or present, if present small or large, compound eye oval or round; acute or 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. 10a and bView FIGURE 10). Antennule with 17–27 lobules, closely or widely arranged; reaches to 9th –12th antennary segment ( Fig. 10aView FIGURE 10). Antenna with 11–13 antennary segments, middle antennary segment anteriorly with two to seven spines ( Fig. 10eView FIGURE 10).

Thorax. 20–23 thorax segments, of these 18–21 "complete" and up to two "incomplete" ( Fig. 10fView FIGURE 10); dorsal spines beginning at 7th –11th thorax segment, eight to twelve 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 ( Fig. 10fView FIGURE 10).

Telson. 11–19 telsonic spines, of these up to two enlarged, telsonic spines end before, at or after base of apex; telsonic filaments situated between second and sixth telsonic spine. Furca with four to ten setae, shorter than, as long as or longer than proximal part of furca; small spine before row of spinules present or absent, spinules short or long ( Fig. 10fView FIGURE 10).

Variability. Females. Carapace. 3.3–5.1 mm high, 4.9–7.2 mm long, height/length ratio 0.65–0.72; height without "crowded" growth lines 3.1–5.1 mm, length without "crowded" growth lines 4.7–7.2 mm; dorso-posterior corner clearly present or nearly absent; 15–23 growth lines, of these 14–21 "non-crowded" and up to eight "crowded"; umbo small or large, cone-shaped or hemispheric, growth lines present or absent.

Head. Section between condyle and external eye contour concave or straight; eye bulge absent or present, if present small or large, compound eye oval or round; acute to right or straight angle between head and rostrum; anterior margin of rostrum straight or convex, transition between anterior and ventral margin rounded or angular. Antennule with 17–22 lobules, closely or widely arranged; reaches to 5th –9th antennary segment. Antenna with 10– 13 antennary segments, middle antennary segment anteriorly with four to six spines.

Thorax. 19–21 thorax segments, of these 18–19 "complete" and one or two "incomplete"; dorsal spines beginning at 5th –11th thorax segment, 9–14 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. 12–22 telsonic spines, of these no or one enlarged, telsonic spines end before, at or after base of apex; telsonic filaments situated between third and sixth telsonic spine. Furca with two to nine setae, shorter than, as long as or longer than proximal part of furca; small spine before row of spinules present or absent, spinules short or long.

Differential diagnosis. Genetically Eocyzicus richteri  sp. nov. and its putative sister species E. breviantennus  sp. nov. are differentiated in COI, but not in the two nuclear markers (Schwentner et al., 2014), which was interpreted as an indication of ongoing reproduction. However, both species can be distinguished morphologically by the total height and length of the carapace and the number of antennary segments ( Tables 1 and 2), which is further supported by correlation plots ( Figs. 4c and dView FIGURE 4). Although E. breviantennus  sp. nov. individuals were usually smaller, they were certainly adult (ovigerous females were present) and exhibited larger numbers for several countable characters (e.g. number of thorax segments; Fig. 4cView FIGURE 4) than E. richteri  sp. nov. Thus, morphological differences between these two species are not explainable by the putative age of the studied specimens. Consequently, the lack of differentiation in the two nuclear markers is assumed to be a result of ancestral polymorphism and incomplete lineage sorting rather than ongoing reproduction. The morphological data support the delimitation of these two species based on the BSC (Mayr, 1942), the PSC sensu Wheeler & Platnick (2000) and the ESC (Wiley & Mayden, 2000).

Distribution and ecology. Eocyzicus richteri  sp. nov. occurs in fresh and turbid water bodies and is sympatrically distributed with Eocyzicus ubiquus  sp. nov., E. phytophilus  sp. nov., E. armatus  sp. nov., E. parooensis  and E. argillaquus  and rarely syntopically with the latter.

COI

University of Coimbra Botany Department

BSC

Centro Oriental de Ecosistemas y Biodiversidad