Eocyzicus armatus, Tippelt & Schwentner, 2018

Tippelt, Lisa & Schwentner, Martin, 2018, Taxonomic assessment of Australian Eocyzicus species (Crustacea: Branchiopoda: Spinicaudata), Zootaxa 4410 (3), pp. 401-452: 433-436

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-FFD7-9116-A180-FD46C26BFB90

treatment provided by

Plazi

scientific name

Eocyzicus armatus
status

sp. nov.

Eocyzicus armatus   sp. nov.

( Figs. 17 View FIGURE 17 and 18 View FIGURE 18 )

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

Etymology. The species name " armatus   ", which means armed, corresponds to the large number of telsonic spines and differentiates this species from the majority of all other Australian Eocyzicus   species.

Type locality. New South Wales, Murray-Darling Basin , Paroo River catchment, Bloodwood Station, Roszkos Paleolake, 29°27´42.9´´S, 144°48´12.5´´E. GoogleMaps  

Type material. Holotype. Male (AM P.89602, GenBank KC583965).

Allotype. Female (AM P.89599, GenBank KC583962).

Paratypes. 3 males (AM P.89589, GenBank KC583952; AM P.89598, GenBank KC583961; AM P.91860, no COI sequence available), 4 females (AM P.91859, no COI sequence available; AM P.89600, GenBank KC583963; AM P.91861, no COI sequence available; AM P.89601, GenBank KC583964) collected by M. Schwentner and B. V. Timms, 19-II-2010.

Further material examined. New South Wales: 1 male (AM P.89597) Freshwater Lake, Bloodwood Station , 29°29´14.7´´S, 144°49´59.0´´E, 19-II-2010 GoogleMaps   ; Northern Territory: 1 male (AM P.89611)   , 1 female (AM P.89610) Lake 20 km of West Erldunda , 25°14´36.5´´S, 132°59´40.3´´E, 10-III-2011 GoogleMaps   ; 1 male (AM P.89605) Island hyposaline lake 60 km of North Kulgera , 25°19´23.2´´S, 133°12´41.7´´E, 10-III-2011 GoogleMaps   ; Western Australia: 3 males (AM P.80900, AM P.89590, AM P.89591)   , 3 females (AM P.89592, AM P.89593, AM P.89594) Deep samphire swamp near Onslow , 21°43´12.3´´S, 115°05´56.5´´E, 12-III-2009 GoogleMaps   ; 1 female (AM P.89603) Samphire swamp a few km south of Onslow , 21°43´S, 115°05´E, 14.03.2009 GoogleMaps   .

Description. Holotype male ( Fig. 17 a, c and d View FIGURE 17 ). Carapace. 4.5 mm high, 7.2 mm long, height/length ratio 0.63; height without "crowded" growth lines 4.1 mm; length without "crowded" growth lines 6.6 mm; shape oval; dorso-posterior corner clearly present; 16 growth lines, of these 15 "non-crowded" and one "crowded"; umbo small, hemispheric, growth lines present ( Fig. 17a View FIGURE 17 ).

Head. Condyle rounded, section between condyle and external eye contour concave; eye bulge large, compound eye round; acute angle between head and rostrum; anterior margin of rostrum convex, transition between anterior and ventral margin angular ( Fig. 17c View FIGURE 17 ). Antennule with 17 lobules, widely arranged; reaches to 8th antennary segment. Antenna with twelve antennary segments, middle antennary segment anteriorly with four spines.

Thorax. 23 thorax segments, of these 21 "complete" and two "incomplete" ( Fig. 17d View FIGURE 17 ); dorsal spines beginning at 8th thorax segment, 14 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. 17d View FIGURE 17 ).

Telson. 13 telsonic spines, of these three enlarged, telsonic spines end after base of apex; telson symmetric; telsonic filaments situated between second and third telsonic spine. Furca with twelve setae, longer than proximal part of furca; small spine before row of spinules present, spinules short ( Fig. 17d View FIGURE 17 ).

Allotype female ( Fig. 17 b, e and f View FIGURE 17 ). Carapace. 4.3 mm high, 6.8 mm long; height without "crowded" growth lines 3.8 mm, length without "crowded" growth lines 5.9 mm; 15 growth lines, of these 13 "non-crowded" and two "crowded" ( Fig. 17b View FIGURE 17 ).

Head. Eye bulge small; obtuse angle between head and rostrum; anterior margin of rostrum straight ( Fig. 17e View FIGURE 17 ). Antennule reaches to third antennary segment. Antenna with 13 antennary segments, middle antennary segment anteriorly with five spines.

Thorax. 21 thorax segments; of these 20 "complete" and one "incomplete" ( Fig. 17f View FIGURE 17 ); dorsal spines beginning at 7th thorax segment, 13 thorax segments with dorsal spines; first dorsal spine smaller than following one, last dorsal spine same size as preceding one, last "complete" thorax segment without dorsal spine ( Fig. 17f View FIGURE 17 ).

Telson. 19 telsonic spines, of these six enlarged; telsonic spines end at base of apex; telsonic filaments situated between fourth and fifth telsonic spine ( Fig. 17f View FIGURE 17 ).

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

Variability. Males. Carapace. 4.3–7.1 mm, 4.5–8.4 mm, height/length ratio 0.61–0.72, height without "crowded" growth lines 3.4–4.6 mm, length without "crowded" growth lines 5.7–7.2 mm; dorso-posterior corner clearly present or nearly absent; 15–35 growth lines, of these 12–27 "non-crowded" and 1–13 "crowded"; umbo 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, compound eye oval or round; acute to right angle between head and rostrum; anterior margin of rostrum straight or convex ( Fig. 18a View FIGURE 18 ). Antennule with 13–20 lobules ( Fig. 18b View FIGURE 18 ); reaches to 7th –10th antennary segment. Antenna with 12–14 antennary segments ( Fig. 18c View FIGURE 18 ), middle antennary segment anteriorly with four to six spines ( Fig. 18d View FIGURE 18 ).

Thorax. 20–23 thorax segments, of these 19–21 "complete" and one or two "incomplete" ( Fig. 18g View FIGURE 18 ); dorsal spines beginning at 5th –11th thorax segment, 10–17 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. 18g View FIGURE 18 ).

Telson. 11–23 telsonic spines, of these four to six enlarged; telsonic spines end at or after base of apex; telsonic filaments situated between 2nd and 7th telsonic spine. Furca with 10–19 setae, spinules short or long ( Fig. 18g View FIGURE 18 ).

Variability. Females. Carapace. 4.3–5.1 mm high, 6.7–7.7 mm long, height/length ratio 0.61–0.66; height without "crowded" growth lines 3.3–4.8 mm; length without "crowded" growth lines 5.2–7.1 mm; dorso-posterior corner clearly present or nearly absent, 14–38 growth lines, of these 13–24 "non-crowded" and 2–15 "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 or obtuse angle between head and rostrum; anterior margin of rostrum concave, straight or convex, transition between anterior and ventral margin rounded or angular. Antennule with 14–17 lobules, closely or widely arranged; reaches to third to sixth antennary segment. Antenna with 10–13 antennary segments, middle antennary segment anteriorly with four or five spines.

Thorax. 21–23 thorax segments, of these 19–22 "complete" and one or two "incomplete"; dorsal spines beginning at 6th –10th thorax segment, 11–15 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.

Telson. 18–28 telsonic spines, of these up to six enlarged, telsonic spines end at or after base of apex; telsonic filaments situated between 3rd and 7th telsonic spine. Furca with 9–18 setae, as long as or longer than proximal part of furca; small spine before row of spinules present or absent.

Differential diagnosis. The species that morphologically is most similar to Eocyzicus armatus   sp. nov. is E. parooensis   . It is possible to distinguish both species by the number of all growth lines on the carapace, of thorax segments and of telsonic spines ( Table 1 and 2). The sister species could not be identified by genetic analyses. Nevertheless, its clear differentiation from all other Eocyzicus   species (Schwentner et al., 2014) supports its delimitated as a species following the PSC sensu Wheeler & Platnick (2000), ESC (Wiley & Mayden, 2000) and BSC (Mayr, 1942). With regard to the species it occurs sympatrically with, it can also be delimited following the BSC (Mayr, 1942).

Distribution and ecology. This species is distributed in clear, fresh and hyposaline water bodies and occurs sympatrically with E. richteri   sp. nov., E. phytophilus   sp. nov., E. argillaquus   , E. parooensis   and E. ubiquus   sp. nov. and is rarely syntopically distributed with the latter species.

BSC

Centro Oriental de Ecosistemas y Biodiversidad