A partial revision of the Australian Eulimnadia Packard, 1874 (Branchiopoda: Spinicaudata: Limnadiidae)
Author
Brian V Timms
text
Zootaxa
2016
4066
4
351
389
journal article
38714
10.11646/zootaxa.4066.4.1
9bcb9426-a7fe-4fc1-972c-dec211390480
1175-5326
264233
B0F56A57-C033-48C6-BB66-B007A93FC259
Eulimnadia contraria
sp. nov.
(
Figs. 9
A,10)
Etymology.
The specific epithet is based on the Latin ‘contrarius’ meaning opposites and refers to the numerous telsonic spines yet few short cercopod setae and to the numerous short spines on the antennomeres as against the sparse setae on many (both numerals are departures from the ‘average’ morphology in
Eulimnadia
).
Type
locality.
Queensland, Aramac district, vicinity of Lake Dunn, excavation on south side of lake,
22o 36’ 12”S
,
145o 40’ 26”E
,
15 February 2010
, MS and
BVT
.
Type
material.
Holotype
.
Hermaphrodite in Australian Museum, Sydney, length
9.8 mm
, height
6.4 mm
,
AMP
91973.
Paratype
.
Hermaphrodite in Australian Museum, Sydney, length
9.6 mm
, height
6.2 mm
.
AMP
91974..
Diagnosis.
Egg with about 15 large deep polygons with long narrow protrusions laterally at ridge junctions. 18 trunk segments. Cercopod with a few short setae spaced along basal 80%. About 24 telsonic spines, all except first and last about same size. Female carapace much vaulted dorsally.
FIGURE 9.
Eulimnadia
eggs. A,
E.contraria
sp. nov
.
(Lake Dunn, Qld); B,
E. gnammaphila
Kooyoora, Vic
); C,
E. gnammaphila
(Peela, SA); D,
E. gnammaphila
(Yanneymooning, WA);
E. hansoni
(Bloodwood, NSW); F,
E. pinocchionis
(Karratha, WA), G,
E. taroomaensis
(Taroom, Qld)
, H,
E. uluruensis
(Uluru, NT); enlargement of portion of egg of
E. uluruensis
. Scale bars 1 mm, except I for which the bar = 0.01 mm.
Description. Egg
(
Fig 9
A) largely spherical but with many soft narrow protrusions at the ridge junctions of the approximately 15 polygons. These polygons deep with smooth inner slopes to a central short groove. Mean diameter 188 Μm (range 178–197 ìm, n = 5).
Hermaphrodite.
Head
(
Fig 10
C) with ocular tubercle prominent, the compound eye occupying most (ca 80%) of it. Rostrum hardly protruding, evenly rounded, ocellus small, placed above centre. Frons-rostrum angle 160o. Dorsal organ posterior to eye by about its height, pedunculate and of similar height as ocular tubercle.
First antenna
a little longer than peduncle of second antenna and with about 8 lobes.
Second antenna
with a spinose peduncle and each flagella with 8 antennomeres, dorsally with 3–8 short spines and ventrally with 0–5 longer setae. Setae most numerous on distal 2 antennomeres and sparse elsewhere, spines most numerous on intermediate antennomeres.
Carapace
(
Fig 10
A) opaque and discoloured dull yellow and much vaulted dorsally and with numerous (ca. 8) growth lines.
Thoracopods.
Eighteen pairs of typical structure for
Eulimnadia
. Trunk dorsum with 3–9 setae terminally, these setae few, short and stout on distal few segments, numerous and longer on segments 8–15 and hardly any setae on anterior trunk segments 1–7.
Telson
(
Fig 10
B) with spine at ventroposterior angle, dorsally with about 24 naked spines, each about the same size and spacing except the first about 1.5x height of others, and the last about
3x
height of others. Caudal filaments originating from a mound a little higher than telsonic floor and at the fifth spine. Dorsal floor declines from mound almost evenly to cercopod base. Cercopod a little longer than telson, the basal 80% with about 7 widely spaced, short setae and demarked from the last 20% by a short spine and thinning to an acute apex. Many tiny denticles dorsolaterally on apical 20%.
FIGURE 10.
Eulimnadia contraria
sp. nov
.
Lake Dunn, Qld.. A, female carapace; B, female telson, C, female head and antennae. Scale bars 1 mm.
Comments.
The markedly vaulted carapace and large number of growth lines could be associated with the advanced age of the holotypic specimen. The numerous dorsal spines and few setae on most antennomeres could be an aberration and not definitive of this species. More distinctive are the few cercopod setae, most of which are only 0.5 x cercopod diameter. This species is
Eulimnadia
sp. E of
Schwentner
et al
. (2015)
. Despite the lack of males and the availability of only two specimens it was described as it is one of the few species able to be matched with molecular species delineated by
Schwentner
et al
. 2015
.
Distribution
.
Eulimnadia contraria
is known only from its
type
locality in central Queensland.