Taxonomic assessment of Australian Eocyzicus species (Crustacea: Branchiopoda: Spinicaudata)
Author
Tippelt, Lisa
Author
Schwentner, Martin
text
Zootaxa
2018
2018-04-18
4410
3
401
452
journal article
30240
10.11646/zootaxa.4410.3.1
4f13056b-fc90-4155-8790-809061971ace
1175-5326
1221684
F81EF784-209A-4933-932D-0A507BA85E2B
Eocyzicus ubiquus
sp. nov.
(
Figs. 5
and
6
)
Eocyzicus
lineage U Schwentner
et al.,
2014, 2015b
Etymology.
The species name is derived from the Latin word "ubique", which means everywhere. This refers to the fact that this species occurs in a wide range of different aquatic habitats
types
(see also "Ecology").
Type
locality.
New
South Wales
,
Murray-Darling Basin
,
Paroo River
catchment,
Bloodwood Station
,
Sues Pan
,
29°29´05.6´´S
,
144°48´38.0´´E
.
Type material. Holotype.
Male (AM P.89515, GenBank
KC583880
).
Allotype.
Female (AM P.89517, GenBank
KC583882
).
Paratypes.
1 male (AM P.89515, GenBank
KC583883
), 2 females (AM P.89516, GenBank
KC583881
; AM P.89519, GenBank
KC583884
), collected by M. Schwentner, S. Richter and B. V. Timms,
21-II-2011
.
Further
material examined.
New
South
Wales
:
1 male
(AM P.89491)
Turbid
pool,
29°32´29.3´´S
,
146°24´50.1´´E
,
21-I-2010
;
1 male
(AM P.89462)
Vegetated
pool 1,
Muella Station
,
29°31´10.3´´S
,
144°56´21.8´´E
,
31-III-2009
;
1 male
(AM P.89513)
Lismore Bore
,
Muella Station
,
29°31´50.7´´S
,
144°59´28.1´´E
,
19-I-2010
; 1 male (AM P.89463),
1 female
(AM P.89464)
Yantabulla
black box swamp,
29°20´18.0´´S
,
145°00´12.1´´E
,
31-III-2009
;
1 female
(AM P.89478)
Black
box swamp near
Cumeroo
,
29°15´41.2´´S
,
145°09´29.0´´E
,
20-I-2010
;
1 male
(AM P.89484)
Gerara
composite swamp,
29°11´47.0´´S
,
146°17´03.0´´E
,
21-I- 2010
;
1 male
(AM P.89501)
Freshwater Lake
,
Bloodwood Station
,
29°29´14.7´´S
,
144°49´59.0´´E
,
19-II-2010
;
1 female
(AM P.89470)
Upper Crescent Pool
,
Bloodwood Station
,
29°32´33.6´´S
,
144°52´16.5´´E
,
19-I-2010
;
1 female
(AM P.89461)
East of Lake Lauradale
, northwest of
Bourke
,
29°51´22´´S
,
145°38´49´´E
,
29-III-2009
;
Western
Australia
:
1 male
(AM P.89514)
Samphire
swamp a few km south of
Onslow
,
21°43´S
,
115°05´E
,
14-III- 2009
;
Queensland
:
1 male
(AM P.89496)
Cane
grass swamp
75 km
east of
Wyandra
,
27°23´03.5´´S
,
146°36´33.7´´E
,
17-II-2010
; 1 male (AM P.89528),
1 female
(AM P.89525)
Old
borrow pit
8 km
east of
Boulia
,
22°55´44.6´´S
,
139°58´23.7´´E
, 0
4-III-2011
;
1 female
(AM P.89498)
Grassy
turbid swamp
10 km
from
Bollon Rd Junction
,
27°41´52.4´´S
,
146°45´44.7´´E
,
18-II-2010
;
1 female
(AM P.89520)
Floodout of Dam
,
84km
south of
Thargomindah
,
28°39´46.7´´S
,
143°48´40.8´´E
,
26-II-2011
.
FIGURE 5
.
Eocyzicus ubiquus
sp. nov
.
a, carapace of male holotype (AM P.89515). b, carapace of female allotype (AM P.89517). c, head of male holotype. d, telson of male holotype. e, head of female allotype. f, telson of female allotype. ce = compound eye, co = condylus, ds = dorsal spine, fu = furca, gl = growth lines, is = „incomplete" thorax segments, md = mandible, ro = rostrum, sp = spinules, tf = telsonic filaments, ts = telsonic spines, um = umbo.
FIGURE 6
.
Eocyzicus ubiquus
sp. nov
.
male paratype (AM P.89518). a, rostrum (left antenna removed). b, fifth and sixth segment of the left antenna. c, first or second right clasper, arrow indicates the scales at the tip of the movable finger. d, detail of the tip of the movable finger of first or second right clasper. e, telson, arrows indicate "incomplete" thorax segments. f, detail of distal part of furca. A1 = antennules, ds = dorsal spine, fu = furca, lp = large palpus, mf = movable finger, ro = rostrum, sc = scales, sp = spinules, tf = telsonic filaments, ts = telsonic spines.
Description.
Holotype
male.
(
Fig. 5a, c and d
).
Carapace
. 5.0 mm high, 7.0 mm long, height/length ratio 0.64; height without "crowded" growth lines
4.1 mm
; length without "crowded" growth lines
6.3 mm
; shape oval; dorso-posterior corner clearly present; 21 growth lines, of these 19 "non-crowded" and two "crowded"; umbo large, hemispheric, growth lines on umbo present (
Fig. 5a
).
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. 5c
). Antennule with 22 lobules, widely arranged; reaches to 10th antennary segment. Antenna with twelve antennary segments, middle antennary segment anteriorly with five spines.
Thorax
. 20 thorax segments, of these 18 "complete" and two "incomplete" (
Fig. 5d
); dorsal spines beginning at 8th thorax segment, eleven thorax segments with dorsal spines; one dorsal spine at each thorax segment; first dorsal spine smaller than following one, last dorsal spine same size as the preceding one, last "complete" thorax segment with dorsal spine (
Fig. 5d
).
Telson.
13 telsonic spines, of these three enlarged, telsonic spines end at base of apex; telson symmetric; telsonic filaments situated at the third telsonic spine. Furca with 13 setae, longer than proximal part of furca; small spine before row of spinules present, spinules long (
Fig. 5d
).
Allotype
female.
(
Fig. 5b, e and f
).
Carapace.
4.4 mm
high,
6.8 mm
long; height/length ratio 0.65; 18 growth lines, of these 16 "non-crowded" and two "crowded"; umbo small (
Fig. 5b
).
Head
. Section between condyle and external eye contour concave; eye bulge small; transition between anterior and ventral margin of rostrum angular (
Fig. 5e
). Antennule reaches to fifth antennary segment. Antenna with middle antennary segment with four spines anteriorly.
Thorax
. 22 thorax segments; of these 20 "complete" and two "incomplete" (
Fig. 5f
); dorsal spines beginning at 7th thorax segment, 13 thorax segments with dorsal spines; first dorsal spine same size as following one; last "complete" thorax segment without dorsal spine (
Fig. 5f
).
Telson.
16 telsonic spines, of these three enlarged, telsonic spines end after base of apex; telsonic filaments situated at fourth telsonic spine. Furca with five setae, as long as proximal part of furca (
Fig. 5f
).
Ovigerous flagella
situated at 9th and 10th thorax segment.
Variability. Males
Carapace.
3.1–5.1 mm
high,
4.9–7.8 mm
long, height/length ratio 0.63–0.68; height without "crowded" growth lines
2.5–5.1 mm
; length without "crowded" growth lines
3.7–7.8 mm
; dorso-posterior corner clearly present or nearly absent; 17–26 growth lines, of these 17–24 "non-crowded" and up to seven "crowded"; umbo small or large, cone-shaped or hemispheric, growth lines present or absent.
Head
. Eye bulge absent or present, if present small or large, compound eye oval or round; 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. 6a
). Antennule with 15–25 lobules, closely or widely arranged; reaches to 8th –13th antennary segment. Antenna with 12–14 antennary segments, middle antennary segment anteriorly with four to seven spines (
Fig. 6b
).
Thorax
. 20–21 thorax segments, of these 18–20 "complete" and one or two "incomplete" (
Fig. 6e
); dorsal spines beginning at 6th–10th thorax segment, 10–15 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 (
Fig. 6e
).
Telson.
11–15 telsonic spines, of these up to four enlarged, telsonic spines end before, at or after base of apex; telsonic filaments situated between the second and fifth telsonic spine. Furca with 3–14 setae, setae shorter than, as long as, or longer than proximal part of furca (
Fig. 6e
); small spine before row of spinules present or absent.
Variability. Females.
Carapace.
3.2–5.2 mm
high, 4.7–8.0 mm long, height/length ratio 0.63–0.68; height without "crowded" growth lines 3.0–
4.8 mm
, length without "crowded" growth lines
4.5–7.3 mm
; dorso-posterior corner clearly present or nearly absent; 12–24 growth lines, of these 11–21 "non-crowded" and up to seven "crowded"; umbo small or large, growth lines present or absent.
Head
. Section between condyle and external eye contour concave or straight; eye bulge absent or present, if present small; acute or straight angle between head and rostrum, transition between anterior and ventral margin of rostrum rounded or angular. Antennule with 15–22 lobules, closely or widely arranged; reaches to 5th –7th antennary segment. Antenna with 11–14 antennary segments, middle antennary segment anteriorly with four to six spines.
Thorax
. 20–22 thorax segments, 19–20 "complete" and one or two "incomplete"; dorsal spines beginning at 7th –10th thorax segment, 10–14 thorax segments with dorsal spines; first dorsal spine smaller than or same size as preceding one; last dorsal spine smaller than or same size as following one, last "complete" thorax segment with or without dorsal spine.
Telson.
12–18 telsonic spines, of these up to three enlarged, telsonic spines end before, at or after base of apex; telsonic filaments situated between second and sixth telsonic spine. Furca with two to twelve setae, shorter than or as long as proximal part of furca; small spine before row of spinules present or absent.
Differential diagnosis.
Eocyzicus ubiquus
sp. nov
.
is hard to distinguish from all other
Eocyzicus
species because of its large intraspecific variability that overlaps with that of many other species (
Table 1
and
2
), especially with
E. argillaquus
(
Fig. 2a and c
). It is possible to differentiate these species morphologically by the total number of growth lines and of telsonic spines.
Eocyzicus ubiquus
sp. nov
.
and
E. argillaquus
are genetically clearly differentiated and not presumed sister species. Because of their sympatric distribution, they are certainly distinct species following the Biological Species Concept (Mayr, 1942), the Phylogenetic Species Concept
sensu
Wheeler & Platnick (2000), and the Evolutionary Species Concept (Wiley & Mayden, 2000).
Eocyzicus ubiquus
sp. nov
.
can be morphologically distinguished from its putative sister species
E
.
timmsi
sp. nov
.
by the number of growth lines and number of lobules on the antennules in females (
Tables 1
and
2
).
Distribution and ecology.
Eocyzicus ubiquus
sp. nov
.
is distributed in a variety of water bodies with very different ecological conditions: in small pools as well as lakes, clear and turbid, fresh and hyposaline water bodies. It occurs sympatrically with
Eocyzicus richteri
sp. nov
.
,
E. phytophilus
sp. nov
.
,
E
.
parvus
sp. nov
.
,
E. argillaquus
,
E. parooensis
, and
E. armatus
sp. nov.
and rarely syntopically with the latter species.