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
Huonella huonensis
gen. et sp. nov.
(
Figs 24–28
)
Type
material.
Holotype
, male,
12 mm
, dissected 4 slides, AM P.76876,
Huon Study Area
,
Hill U
Seamount,
Tasmania
(
44°19′30″S
147°10′47″E
),
1140 –1200 m
,
1 April 2007
, coll.
S.J. Keable
,
RV Southern Surveyor
(SS
02/ 2007/12
)
;
paratype
, male specimen,
16 mm
, AM P.76877, Cascade Plateau, Premium Seamount,
Tasmania
(
43°55′13″S
150°27′48″E
),
590 –660 m
,
10 April 2007
, coll.
S.J. Keable
,
RV Southern Surveyor
(SS02/2007/75; SS station accession number 075-035).
Type
locality.
Huon Study Area
,
Hill U
Seamount,
Tasmania
(
44°19′30″S
147°10′47″E
).
Etymology.
Named from the
type
locality.
Description.
Based on
holotype
male,
12 mm
, AM P.76876.
FIGURE 24.
Huonella huonensis
gen. et. sp. nov.
, paratype male, 16 mm, AM P.76877, Cascade Plateau, Premium Seamount, Tasmania. Image by Karen Gowlett-Holmes, CSIRO.
FIGURE 25.
Huonella huonensis
gen. et. sp. nov.
, holotype male, 12 mm, AM P.76876, Huon Study Area, Hill U Seamount, Tasmania.
FIGURE 26.
Huonella huonensis
gen. et. sp. nov.
, holotype male, 12 mm, AM P.76876, Huon Study Area, Hill U Seamount, Tasmania, scales 0.4 mm.
FIGURE 27.
Huonella huonensis
gen. et. sp. nov.
, holotype male, 12 mm, AM P.76876, Huon Study Area, Hill U Seamount, Tasmania, scales 0.1 mm.
Head
.
Eyes
ovate; lateral cephalic lobe broad, rounded, apically rounded, anteroventral margin with notch, anteroventral corner acute.
Antenna 1
longer than antenna 2; peduncular article 1 subequal to article 2, with 5 proximal robust setae on posterior margin; peduncular article 2 longer than article 3; flagellum articles longer than broad, with 19–23 articles; accessory flagellum long, near half length of primary flagellum, with 10–11 articles.
Antenna 2
peduncular article 4 longer in length than article 5; flagellum with 10 articles.
Mandible
accessory setal row, well developed with 10 setae; palp well developed, article 1 length 1.4 × width, shorter than article 2; article 2 longer than article 3, with many slender setae; article 3 rectilinear, long, 3.6 × as long as broad, longer than article 1, many marginal setae and 2 apical slender setae.
Lower lip
without apical ducts, mandibular lobes apically rounded.
Maxilla 1
inner plate subquadrate, with 3 apical plumose setae.
Maxilla 2
without medial setal row.
Pereon
.
Gnathopod 1
coxa anterior margin concave, anteroventral corner produced, acute, posteroventral corner without notch; merus with subquadrate posteroventral corner; carpus length 3 × width, 1.5 × propodus length, with rows of setae covering medial surface; propodus subovate, medial surface setal comb absent; palm subacute, convex, entire, lined with robust setae, defined by robust seta; dactylus closing along palm.
Gnathopod 2
size symmetrical; subchelate; coxa posteroventral corner without notch; basis slender, anterodistal corner subquadrate, margin with a few long slender setae; merus with acute posteroventral corner; carpus compressed, length 1.1 × width, anterior margin without setae, posterior margin with rows of long slender setae; propodus subovate, length 1.6 × width, margin with rows of slender setae, palm angle subacute, margin sculpted, lined with robust setae, posterodistal shelf subtriangular with 4 pair of robust setae, palm defined by posteroventral corner with large subacute tooth and three robust setae; dactylus closing along and reaching end of palm, posterior margin smooth, lined with setules, unguis absent.
Pereopod 4
coxa without posterodistal lobe.
Pereopods 5–6
slender distally; basis not expanded, posterior margin straight, serrate, with long slender setae; merus and carpus not broadened; dactylus unguis simple.
Pereopod 7
slender distally; basis not expanded, posterior margin sinusoidal, serrate, with long slender setae; merus and carpus not broadened; dactylus unguis simple.
Pleon
.
Pleonites 1–3
dorsally smooth.
Epimera 1–2
posterodistal corner acute.
Epimeron 3
posterior and ventral margins smooth, corner acute.
Urosomites 1–3
without carina.
Uropod 1
peduncle with 1 basofacial seta, peduncle length 1.3 × outer ramus; inner ramus subequal to outer ramus.
Uropod 2
peduncle length subequal to outer ramus; inner ramus longer than outer ramus.
Uropod 3
rami unequal in length, with apical slender setae; inner ramus length 0.4 times outer ramus, length 5.8 times width; outer ramus 2 articulate, length 3.7 times peduncle, length 7.6 times width, article 2 minute, vestigial.
Telson
deeply cleft, length 1.5 times width, lobes parallel, apically rounded, with 1 pair of subapical robust setae, without inner or lateral robust setae.
FIGURE 28.
Huonella huonensis
gen. et. sp. nov.
, holotype male, 12 mm, AM P.76876, Huon Study Area, Hill U Seamount, Tasmania, scales 0.4 mm.
Remarks.
Both specimens are without serrations along the dorsal margins, have symmetrical enlarged gnathopod 2 propodus, a smooth epimeron 3 and both specimens show the reduced inner ramus, confirming that these character are not an artefact of damage.
The shorter inner ramus of uropod 3 separates
Huonella huonensis
gen. et. sp. nov. from the closely aligned
Ceradocus
and
Linguimaera
genera. The gnathopod 2 propodus palm sculpturing is similar to two other southern hemisphere species,
Ceradocus circe
Lowry & Springthorpe, 2005
from southern
Australia
and
Maera tepuni
J.L.Barnard, 1972b
from
New Zealand
.
Distribution.
Australian.
Tasmania
: Hill U Seamount, Premium Seamount (current study).