Taxonomy of Paraplatyarthrus Javidkar and King (Isopoda: Oniscidea: Paraplatyarthridae) with description of five new species from Western Australia, and comments on Australian Trichorhina Budde-Lunde, 1908 (Platyarthridae)
Author
Javidkar, Mohammad
Author
King, Rachael A.
Author
Cooper, Steven J. B.
Author
Humphreys, William F.
Author
Austin, Andrew D.
text
Zootaxa
2017
4243
3
401
431
journal article
36268
10.11646/zootaxa.4243.3.1
1e56377e-aef3-4991-bcde-bc857fd36926
1175-5326
400092
06BB3BA9-E53C-4EF9-BD58-B853BF64B88D
Paraplatyarthrus pallidus
Javidkar and King
,
sp. nov.
Figs 17–19
,
2
G, 20B
urn:lsid:zoobank.org:act:149ADE06-BD8E-4517-A3D4-F3A2182CEEF8
Type
material.
Holotype
: Male,
WAM
C 54803 (BES15545.2),
Lake Miranda East
calcrete aquifer,
Yakabindie
pastoral station,
Eastern
Murchison region
,
Western
Australia
,
Australia
;
27.66405°S
,
120.61015°E
,
Jul 2010
, coll.
S.J.B. Cooper
&
W.F. Humphreys.
Paratypes
:
Lake Miranda East
:
2 females
(
WAM
C 54804, BES15545.8;
WAM
C 54805, BES15545.3)
,
3 males
(
WAM
C 54806, BES15545.11;
WAM
C 54807, BES15545.10;
WAM
C 54808, BES15545.6) (same locality and collection data as
holotype
)
, 1 female (WAM C 66909, BES15543.3), 1 male (WAM C 66910, BES17215.2), 27.66384°S, 120.61076°E,
May 2012
, coll. S.J.B. Cooper & W.F. Humphreys.
Lake Miranda West
(same calcrete as
holotype
):
2 males
(
WAM
C 66897,
BEST
15538.2
;
WAM
C 66898, BES15538.3)
, 2 females (WAM C 66899, BES15538.14; WAM C 66908, BES15538.10), 27.74667°S, 120.5266°E,
Jul 2010
, coll. S.J.B. Cooper & W.F. Humphreys.
Diagnosis.
Single significantly reduced black ommatidium-like component (vestigial) with no eye structure. Body pale. Maxilla 2 with no delimiting line between lobes, inner lobe contracted into small area in distal inner apical corner. Uropodal sympodite with incision on outer margin, apically truncated and merging with proximal sympodite. D/C ratio is relatively constant in tergites 1–7, except for one next to lateral margin in tergite 7.
Description. Male
(WAM C 54803),
Body
length
2.7 mm
, completely pale (
Fig. 2
G). Cephalon lateral lobes small, with straight sides. Eyes significantly reduced, with only 1 dark ommatidium-like component (vestigial) with no external eye structure.
Antenna 1
medial article shortest, distal article longest, seemingly bearing 6 aesthetascs on top (
Fig. 17
A).
Antenna 2
flagellum with basal article short, about 1/3 of distal one.
Left mandible
(
Fig. 17
B) pars molaris with about 8 plumose setae; hairy lobe bearing 2 plumose setae, with no small fine setae.
Right mandible
pars molaris with probably more than 4 plumose setae; 1 plumose seta on hairy lobe.
Maxilla 1
outer endite (
Fig. 17
C) with outer group of 4 teeth covering about 65% of marginal area, inner group of 2 cleft, 2 simple and 1 truncated tooth; inner endite (
Fig. 17
D) with 3 fine setae on subapical outer marginal corner.
Maxilla 2
(
Fig. 17
E) not apically bilobate (delimiting line hardly recognisable); inner lobe contracted into small area on distal inner corner.
Maxillipedal
endite (
Fig. 17
F) with 1 large seta close to subapical inner corner; distal articles of palp with 1 large proximal seta, medial tuft of 2 or 3 simple setae and apical tuft of few long setae.
Epimeron 1
bluntly projected anteriorly. In dorsal view, posterolateral corner of
pereonites 1–4
rounded. Posterolateral corner of
pereonites 5–7
posteriorly directed (
Fig. 20
B).
Pleonite 5
posterior corner reaching uropod sympodite but not surpassing it. with
Noduli laterales
at approximately same distance from posterior margin in tergites 2–7; D/C ratio is relatively constant in tergites 1–7, except for one next to lateral margin in tergite 7 (Appendix 2).
Pereopod 1
carpus inner side with long simple and serrate setae, tuft of fine setae present medially near distal margin (
Fig. 18
A); propodus with both small simple and large serrate setae; dactylus with long seta exceeding claws, outer claw relatively straight.
Pereopod 7
carpus not showing sexual dimorphism (
Fig. 18
B).
Pleon
outline continuous with pereon.
Pleopod 1
endopodite (
Fig. 19
A) moderately acute, with narrow spermatic furrow and few very fine setae close to distal part; exopodite (
Fig. 19
B) with no marginal setae, posterior point not developed. Genital papilla ventral sheath apically pointed and surpassed by long rounded-tip lobe (
Fig. 19
A).
Pleopod 2
endopodite (
Fig. 19
C) long and very slender closer to distal end.
Pleopod 2–5
exopodites with 3 to 4 medium to large simple and serrate setae (
Fig. 19
D–G).
Pleotelson
pointed.
Uropodal
exopodites surpassing pleotelson; endopodites slightly exceeding pleotelson; sympodite with extended incision and truncated apex linking proximal and distal sympodite (
Fig. 18
C).
Etymology.
The new species name is taken from the Latin ‘pallidus’ alluding to its pale body.
Remarks.
Paraplatyarthrus pallidus
sp. nov
.
has a minimum
COI
divergence of 16.5% from the described
Paraplatyarthrus
species (Appendix 1).
Paraplatyarthrus pallidus
is easily distinguished based on having only 1, significantly reduced, pale dark ommatidium-like component (vestigial) with no external eye structure, a pale body, Maxilla 2 not apically bilobate (delimiting line hardly recognisable), and the incision on the uropod sympodite merging with the proximal sympodite. The body length varies between
2.7 mm
and 4.0 mm. This species was referred to as Taxon
4 in
Javidkar
et al.
(2015)
. It is restricted to the Lake Miranda East/West calcrete, Yakabindie pastoral station,
Eastern
Murchison region,
Western
Australia
.