Maeridae from the Indo-Pacific: Elasmopus, Leeuwinella gen. nov., Maeropsis, Pseudelasmopus and Quadrimaera (Amphipoda: Crustacea)
Author
Hughes, Lauren E.
text
Zootaxa
2015
4059
2
201
256
journal article
39226
10.11646/zootaxa.4059.2.1
7dbcc655-553b-4d35-8562-1a98c4555b89
1175-5326
232164
F9ED6784-D8C0-409E-9E4F-73879B265BC4
Quadrimaera brownorum
sp. nov.
(
Figs 29–32
)
Type
material.
Holotype
male,
4.5 mm
, dissected, 3 slides, AM P.92677, Cape
Leveque
, Cygnet Bay, Western
Australia
,
16°28'40"S
,
123°02'06"E
, hand collected on snorkel,
10 April 2008
, coll. J. Jelbart, MI WA 1068.
Paratypes
:
1 female
,
4.5 mm
, dissected, 3 slides, AM P.92790Cape
Leveque
, Cygnet Bay, Western
Australia
,
16°28'40"S
,
123°02'06"E
, hand collected on snorkel,
10 April 2008
, coll. J. Jelbart, MI WA 1068;
12 specimens
, AM P.80976, Cape
Leveque
, Cygnet Bay, Western
Australia
,
16°28'40"S
,
123°02'06"E
, hand collected on snorkel,
10 April 2008
, coll. J. Jelbart, MI WA 1068.
Type
locality.
Cape
Leveque
, Cygnet Bay, Western
Australia
1628'40"S, 12302'06"E.
Etymology.
Named in honor of the Brown family, owners of the Cygnet Bay Pearl Farm, whose gracious support made collecting in Cape
Leveque
possible.
FIGURE 29.
Pseudelasmopus walkerae
sp. nov.
holotype male, 3 mm, AM P.92517, Emily Bay, Norfolk Island, scales 0.1 mm.
Description.
Of
holotype
male,
4.5 mm
AM P.92677.
Head.
Eyes
round; lateral cephalic lobe broad, apically truncate, anteroventral margin with excavate, anteroventral corner acute.
Antenna 1
longer than antenna 2; peduncular article 1 shorter than article 2, with 1 long distal slender robust setae on posterior margin; peduncular article 2 longer than article 3; flagellum articles as long as broad, or broader than long, with 13 articles; accessory flagellum long, more than half length of primary flagellum, with 6 articles.
Antenna 2
peduncular article 4 longer than article 5; flagellum with 8 articles.
Mandible
accessory setal row, well developed with 4 setae; palp well developed, article 1 length 1.9 × width, shorter than article 2, inner margin weakly produced rounded; article 2 length 0.9 × article 3, lined with long slender setae; article 3 rectilinear, long, 2.5 × as long as broad, longer than article 1, with 3 lateral and 3 apical slender setae.
Pereon.
Gnathopod 1
coxa anterior margin straight, anteroventral corner subquadrate, not produced, ventral margin without robust setae, posteroventral corner without notch; basis anterodistal corner without lobes; ischium anterodistal corner without lobes; merus with posteroventral corner subquadrate; carpus length twice width, 1.5 × propodus length, posterior margin lined with long setae, with rows of setae covering medial surface; propodus subovate, medial surface setal comb absent, palm subacute, weakly convex, entire, lined with slender setae, defined by posterodistal corner with 1 robust seta; dactylus closing along palm, unguis present.
Gnathopod 2
subchelate; coxa posteroventral corner without notch, ventral margin without robust setae;
basis broad, anterodistal corner lateral margin with well-developed lobe; ischium anterodistal corner without lobe;
merus with subquadrate posteroventral corner; carpus compressed, length 0.6 × width, anterior margin with 1 robust seta, posterior margin with a few slender setae;
propodus
quadrate, length 1.1 × width, posterior margin with a few slender setae,
palm
length one third of propodus posterior margin, angle transverse,
distal shelf subquadrate with 4 pairs of robust setae, palm with rounded medial excavation and subacute projection margin lined with robust setae,
palm defined by posteroventral corner (90° angle,
large subacute tooth and 1 robust seta
;
dactylus broad, falcate, posterior margin with medial sinus,
reach end of and closing along palm.
Pereopods 3–4
coxa subquadrate; basis long, length 3 × width; merus, carpus and propodus not broadened; dactylus unguis bicuspidate.
Pereopods 5–7
basis expanded, posterior margin weakly serrate, posteroventral corner rounded; merus and carpus expanded; dactylus unguis bicuspidate.
Pereopod 7
propodus expanded
.
FIGURE 30.
Quadrimaera brownorum
sp. nov.
holotype male, habitus, 4.5 mm, AM P. 92677, Cygnet Bay, Western Australia.
Pleon.
Pleonites 1–3
dorsally smooth.
Epimera 1–3
posterior and ventral margins smooth, posteroventral corner with acute tooth.
Uropod 1
peduncle with 1 basofacial seta, length 1.4 × outer ramus; inner ramus slightly longer than outer ramus.
Uropod 2
peduncle shorter than outer ramus; inner ramus slightly shorter than outer ramus.
Uropod 3
peduncle 0.9 × inner ramus; inner ramus shorter than outer ramus, length 1.6 × width, apically truncate with long robust setae.
Telson
as long as broad, deeply cleft (80%), lobes weakly divergent, scarely tapering distally,
lobes apically truncate
,
each lobe with 5–7 apical robust setae
.
Remarks.
The convex palm of gnathopod 2 and dactylus posterior margin with sinus align Q.
brownorum
sp. nov.
with
Q. gregoryi
sp. nov
also from Western
Australia
, as well as
Q. inaequipes
(
A. Costa, 1851
)
from the Caribbean and
Q. massavensis
(Kossman, 1880)
from north east Africa and female specimens of
Q. santiniae
Krapp-Schickel & Ruffo, 2006
from the isolated Amsterdam
Island
in the Indian Ocean. The more distally broad dactylus of gnathopod
2 in
males and females separates
Q. brownorum
sp. nov.
from the latter species. The telson apical margins are also more densely setose in
Q. brownorum
sp. nov
with 5 long robust setae while
Q. gregoryi
and
Q. massavensis
have only 3 robust setae,
Q. inaequipes
2 or 3 robust setae and only 2 robust setae in
Q. santiniae
.
Distribution.
Western
Australia
: Cygnet Bay (current study).