New genera, species and records of Maeridae from Australian Waters: Austromaera, Ceradocus, Glossomaera, Hamimaera, Huonella gen. nov., Linguimaera and Maeraceterus gen. nov. (Crustacea: Amphipoda)
Author
Hughes, Lauren E.
text
Zootaxa
2016
4115
1
1
81
journal article
10.11646/zootaxa.4115.1.1
1cfd5ba9-621f-4abd-97bc-20beb462e2fd
1175-5326
255539
C0CF41A3-40FB-428E-8933-02115AB0F6E3
Maeraceterus bramblensis
gen. et sp. nov.
(
Figs 60–62
)
Type
material.
Holotype
male,
5.1 mm
, dissected, 4 slides, AM P.79457,
Princess Royal Harbour
,
Bramble Point
,
Western
Australia
(
35°2'S
117°55' E
),
1–1.5 m
, on seagrass
Poisidonia australis
, diver held corer,
January 1988
, coll.
P. Hutchings
and party.
Additional material examined.
Tasmania
:
1 male
, dissected, 4 slides, AM P. 97857,
North East River
(
39°46′S
147°58′E
), depth unknown,
8 May 1997
, coll.
A. Davey
(
CAM
78
)
;
1 b female, dissected, 1 slide, AM P.88467,
North East River
(
39°46′S
147°58′E
), depth unknown,
8 May 1997
, coll.
A. Davey
(
CAM
78
)
.
FIGURE 60.
Maeraceterus bramblensis
gen. et sp. nov.
, holotype male, 5.1 mm, AM P.79457, Bramble Point, Western Australia.
Type
locality.
Princess Royal Harbour
,
Bramble Point
,
Western
Australia
(
35°2′S
117°55′ E
).
Etymology.
Named from the
type
locality.
Description.
Based on
holotype
male,
5.1 mm
, AM P.79457.
Head.
Eyes
ommatidea scattered
; lateral cephalic lobe broad, apically rounded, anteroventral margin with notch/slit, anteroventral corner truncate.
Antenna 1
longer than antenna 2; peduncular article 1 shorter than article 2, with 1 robust seta posterodistally; peduncular article 2 longer than article 3; flagellum articles as long as broad, with 16 articles; accessory flagellum short, significantly less than half length of primary flagellum, with 3 articles.
Antenna 2
peduncular article 4 longer in length than article 5; flagellum with 10 articles.
Mandible
accessory setal row, well developed with 5 setae; palp well developed, article 1 length 0.9 × width, shorter than article 2; article 2 longer than article 3, with a few slender setae; article 3 rectilinear, long, 3.5 × as long as broad, longer than article 1, with 3 apical slender setae.
Lower lip
lobes without apical ducts; mandibular lobes apically rounded.
Maxilla 1
inner plate with 3 apical plumose setae; outer plate palp with apical slender setae.
Pereon.
Gnathopod 1
coxa anterior margin concave, anteroventral corner produced, subacute, posteroventral corner without notch; merus with posteroventral corner subquadrate;
carpus
length twice width, 1.3 × propodus length,
without rows of short medial setae;
propodus rectilinear, medial surface setal comb absent, palm subacute, weakly convex, entire, with weakly defined posterodistal corner; dactylus closing along palm.
Gnathopod 2
symmetrical, subchelate; coxa posteroventral corner without notch; basis broad, anterodistal corner with pair of well-developed rounded lobes; ischium anterior margin with pair of well-developed lobes; merus with subacute posteroventral corner; carpus compressed, length 0.9 × width, posterior margin with long slender setae;
propodus
subovate, length 1.8 × width, posterior margin with clusters of long slender setae, palm angle subacute, posterodistal shelf subrectangular, margin sculpted,
with 4 rounded teeth, palm weakly defined with small rounded tooth, without robust setae;
dactylus closing along and reaching end of palm.
Pereopod 4
coxa without posterodistal lobe.
Pereopods 5–7
slender distally; basis posteriorly expanded, margin weakly convex, without long slender setae; merus and carpus slightly broadened; dactylus unguis simple.
Pereopod 6
basis larger than pereopod 7.
Pleon.
Pleonites 1–3
dorsally smooth.
Epimera 1–3
posterior margin smooth, corner with small tooth.
Urosomites 1–3
without carina.
Uropod 1
peduncle with 1 basofacial seta; rami subequal, 0.9 × peduncle length.
Uropod 2
peduncle length 0.8 × outer ramus; inner ramus longer than outer ramus.
Uropod 3
unknown.
Telson
deeply cleft, length subequal to width, lobes weakly divergent, tapering distally, lobes apical margins concave,
each lobe with 3 apical and 1 lateral pair of robust setae
.
Remarks.
Maeraceterus bramblensis
gen. et sp. nov. differs from
M. taaroa
gen. et sp. nov. in the number of teeth on the male gnathopod 2 palm and the absence of a palm defining robust setae which is present in the latter species. In
M. bramblensis
the ischium is without robust setae while
M. taaroa
has a well-developed row of long robust setae on the posterior margin.
FIGURE 61.
Maeraceterus bramblensis
gen. et sp. nov.
, holotype male, 5.1 mm, AM P.79457, Bramble Point, Western Australia, scales 0.1 mm.
Maeraceterus bramblensis
has the unusual state of pereopod 6 basis being larger than that of the pereopod 7 basis (observed on both left and right sides of the
holotype
). This character is not observed in
M. taaroa
and therefore is considered a species rather than generic level character.
Distribution.
Australia
.
Western
Australia
: Bramble Point (current study).
Tasmania
: North East River (current study).