Pseudambasia lochi Kilgallen & Lowry, 2013, sp. nov.
Creators: name: Kilgallen, N. M.
name: Lowry, J. K.
Publisher: name: Zenodo
Year: 2013
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Amphipoda
Lysianassidae
Pseudambasia
Pseudambasia lochi

description: Pseudambasia lochi sp. nov.
(Figs 4–6)
Type material. Holotype, female, 3.9 mm, AM P.68940, 19 km from Mt Young, toward Wallaroo, Spencer Gulf, South Australia (33°18'S 137°31'E), 18 m, K. Sheard, 8 March 1938. Paratypes: 1 female, 5.1 mm, AM P.68941; 1 specimen (? male), 3.3 mm, AM P. 68866; 1 male, 3.7 mm, AM P.68942; all same locality information as holotype.
Additional material examined. 1 female, 3.9 mm, AM P.68861, southeast side of Gabo Island, Victoria (37º34’S 149º55’E), 1 m, P.A. Hutchings, 14 February 1973. 2 specimens, AM P.68868, Australia, South Australia, north-east of Wardang Island, Spencer Gulf (34°30'S 137°22'E), dredge, 7.2 m, K. Sheard, 12 March 1938; 1 male, 4.5 mm, AM P.68865, Australia, South Australia, Bay of Shoals, Kangaroo Island, (35°37'S 137°36'E), algae, 0 m, I. Loch, E.K. Yoo & K. Handley, 7 March 1978.
Type locality. 19 km from Mt Young, toward Wallaroo, Spencer Gulf, South Australia (33°18'S 137°31'E).
Etymology. Named for Ian Loch, one of the collectors.
Description. Based on holotype, female, 3.9 mm, AM P.68940. Head lateral cephalic lobe broadly rounded; eyes oval. Antenna 1 short; peduncular article 1 short, length 1.4 × breadth, without dorsal lobe; peduncular article 2 long, 1.6 × article 1; peduncular article 3 long; 0.25 × article 1; accessory flagellum short, 0.16 × primary flagellum, 2-articulate, article 1 short; primary flagellum 9-articulate, without callynophore, with aesthetascs on most flagellar articles. Antenna 2 flagellum 4-articulate. Mandible accessory setal row with 4 multiserrate setae; molar reduced, represented by finely setose triangular flap; palp attached extremely proximally; article 1 long, length 2.9 × breadth; article 3 slender, blade-like, with distal crease. Maxilla 1 inner plate with small sharp apical robust seta; outer plate broad, with 11 setal teeth, setal teeth 1 – 5 of outer row with cusps in 2 rows; palp 2- articulate, apical margin with 3 sharp spines and 2 robust setae. Labium outer lobes without distolateral stylets. Maxilliped inner plate without apical nodular robust setae; distolateral corner with distinct sharp spine and large robust seta.
Gnathopod 1 weakly subchelate; coxa anterior margin slightly concave, anteroventral corner rounded, coxa posterior margin straight; carpus short, length 1.6 × breadth, subequal in length to propodus; propodus subtriangular, length 1.6 × breadth, palm extremely acute, margin straight, rugose. Gnathopod 2 carpus long, length 4 × breadth; palm transverse, with slightly convex margin. Pereopod 5 coxa equilobate. Pereopod 6 coxa not produced; basis posterodistal corner produced beyond ischium, forming rounded lobe. Pereopod 7 basis expanded posteriorly, posterodistal margin oblique, posterodistal corner moderately produced, forming lobe produced halfway along merus; merus slightly expanded posteriorly.
Epimeron 3 posteroventral corner subquadrate. Uropod 1 outer ramus slightly longer than inner ramus. Uropod 2 outer ramus slightly longer than inner ramus; inner ramus with strong constriction. Uropod 3 peduncle short, with small dorsolateral flange; rami slender. Telson as long as broad, length 0.9 × breadth, lateral margins subparallel to slightly converging distally; apical margin straight.
Sexually dimorphic characters. Based on male, AM P.68942. Gnathopod 1 subchelate; propodus length 1.4 × breadth; palm acute.
Remarks. Pseudambasia lochi appears to be most similar to P. nui from Fiji. Both have a strongly constricted inner ramus on uropod 2, a narrowly rounded/subquadrate posteroventral corner on epimeron 3, but P. nui has a weakly subchelate female gnathopod 2 and an extremely long carpus on gnathopod 2. The telson of P. l o c h i is also very different to that of P. n u i, the lateral margins of which are more strongly tapering in P. n u i and the apical margin is subacute.
Distribution. Gabo Island, Victoria to Spencer Gulf, South Australia.
description: Published as part of Kilgallen, N. M. & Lowry, J. K., 2013, The lysianassid genus Pseudambasia in Australian waters (Crustacea, Amphipoda, Lysianassidae, Lysianassinae), pp. 301-321 in Zootaxa 3710 (4) on pages 307-309, DOI: 10.11646/zootaxa.3710.4.1, http://zenodo.org/record/216146