Huonella huonensis
Creators: name: Hughes, Lauren E.
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Amphipoda
Maeridae
Huonella
Huonella huonensis

description: 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.
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.
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).
description: Published as part of Hughes, Lauren E., 2016, New genera, species and records of Maeridae from Australian Waters: Austromaera, Ceradocus, Glossomaera, Hamimaera, Huonella gen. nov., Linguimaera and Maeraceterus gen. nov. (Crustacea: Amphipoda), pp. 1-81 in Zootaxa 4115 (1) on pages 37-41, DOI: 10.11646/zootaxa.4115.1.1, http://zenodo.org/record/255539