Oedicerina loerzae, Coleman, Charles Oliver & Thurston, Michael H., 2014

Coleman, Charles Oliver & Thurston, Michael H., 2014, A redescription of the type species of Oedicerina Stephensen, 1931 (Crustacea, Amphipoda, Oedicerotidae) and the description of two new species, Zoosystematics and Evolution 90 (2), pp. 225-247 : 228-230

Taxon classification Animalia Amphipoda Oedicerotidae

Oedicerina loerzae sp. n. Figs 11, 12, 13, 14, 15, 16

Holotype.

Male, 8.5 mm; NIWA 84727, TAN 0705-41, Chatham Rise, 43°50 ‘10.8“ S 176°42 ‘33.0“ E, 478-479 m, 5 April 2007. Paratypes. Male?, 7.7 mm; NIWA 89970, TAN 0705-251, Chatham Rise, 42°59 ‘45.0“ S 178°59 ‘44.4“ E, 520-530 m, 24 April 2007; ovig. female, 7 mm; NIWA 84740, TAN0705-83, Chatham Rise, 43°50 ‘10.8“ S 176°42 ‘33.0“ E, 529-530 m; 9 April 2007.

Etymology.

The species is named for Dr. Anne-Nina Lörz to acknowledge her significant contributions to amphipod systematics.

Description.

Holotype male, 8.5 mm. Head (Fig. 11a): longer than high, somewhat longer than pereonites 1-2 combined; no eyes or ocular pigment visible; rostrum (Fig. 11c) strongly deflexed, the ventral margin weakly convex. Antenna 1 (Fig. 12a): shorter than antenna 2; length ratios of peduncle articles 1-3 1:0.5:0.3; flagellum 19-articulate, first article as long as peduncle article 3, proximal articles wider than long; accessory flagellum 1-articulate, minute, 0.3 × length of primary flagellum article 1. Antenna 2 (Fig. 12c): peduncle setose; length of article 4 1.2 × article 5; flagellum 23-articulate, 1.9 × length of peduncle article 5. Upper lip (labrum) (Fig. 11b): wider than long, truncate apically. Mandible (Fig. 12b, d): incisor 5-dentate; left lacinia mobilis wide and multidentate, right narrower; palp 3-articulate, article 3 tapered, length ratios articles 1-3 1:3.9:4.9. Lower lip (Fig. 11d): inner lobes short and broad, hypopharyngeal gap wide, outer lobe mandibular processes acute. Maxilla 1 (Fig. 11e): inner fig tapered, with one distal seta; outer fig with nine acute setal-teeth; palp 2-articulate, article 2 2.6 × length of article 1. Maxilla 2 (Fig. 12f): inner fig 1.1 × wider than outer fig; both figs with relatively sparse apical setation. Maxilliped (Fig. 13a): inner fig (Fig. 12g) short, extending just beyond base of palp article 1; outer fig (Fig. 12e) extending 30% along palp article 2; concave medially; palp (Fig. 13b) 4-articulate; article 1 tapered; article 2 broad, strongly expanded medially, lobe broadly rounded; article 3 narrow proximally, expanded mediodistally; article 4 acute, weakly curved: length ratios of articles 1-4 1:1.7:0.7:1.2.

Pereon. Pereonite 1 (Fig. 11a) longer than 2; pereonite 2 subequal to 3; pereonite 7 longest. Gnathopod 1 (Fig. 13c): coxa subtriangular, posterior margin straight, anterodistal corner rounded, posterodistal corner subrectangular, distal margin straight, setose; basis expanded distally, posterior margin with scattered setae, anterior margin distal half with a row of long setae; merus, posterodistal lobe rounded, setose; carpus subtriangular, strongly expanded distally, anterior, distal and posterior margins setose; propodus strongly expanded distally, as wide and as long as carpus, anterior and posterior margin convex, palm transverse, convex, crenellate, setose; dactylus slightly curved, just longer than palm. Gnathopod 2 (Fig. 14a, b): coxa as long as coxa 1, anterior and posterior margins subparallel, apex truncate, weakly setose; basis a little expanded, with some plumose setae near posterior and distal margins and an anterodistal group of long simple setae; merus, with angular posterodistal lobe short, narrow, setose; carpus strongly expanded, wider than propodus, posterodistal lobe subacute, distal margin oblique; propodus shorter than carpus, expanded distally, palm straight, crenellate; dactylus curved, just longer than palm. Pereopod 3 (Fig. 14c): coxa subequal to coxa 2, apex truncate; basis shorter than coxa, long plumose setae on posterior margin and close to anterior margin; merus weakly expanded anterodistally; carpus, length and breadth subequal to merus; propodus subrectangular, anterodistal and posterior margins setose; dactylus 1.4 × length of propodus. Pereopod 4 (Fig. 14d): coxa wider than long, anterior margin weakly convex, distal margin broadly rounded, anterodistal angle subrectangular, posterodistal lobe very strong, posterodistal angle rounded; basis shorter than coxa, anterior and posterior margins setose; merus weakly expanded anterodistally, setose; carpus 0.9 × merus, posterior margin convex, strongly setose, long setae anterodistally; propodus, anterodistal margin strongly setose, posterior margin setose; dactylus stout, straight, 1.8 × propodus. Pereopod 5 (Fig. 15a): coxa 0.9 × length of coxa 4, bilobed, posterior lobe expanded distally, distal margin straight, anterior lobe 0.6 × length of posterior lobe, rounded distally; basis shorter than coxa, few plumose setae on each margin; merus as long as basis, carpus 0.4 × length of merus; propodus slender, 0.7 × length of merus, shorter than the straight lanceolate dactylus; articles 2-6 variously setose. Pereopod 6 (Fig. 15c): coxa 0.7 × length of coxa 5, bilobed, posterior lobe subtriangular, anterior lobe 0.5 × length of posterior lobe; basis subrectangular, long plumose setae anterodistally; merus posterior margin convex; carpus subrectangular, 0.5 × length of merus; propodus 0.9 × length of merus; dactylus straight, lanceolate, as long as merus; articles 3-6 variously setose. Pereopod 7 (Fig. 15b): long; coxa wider than long, rounded posterodistally; basis, margins convex, posterodistal lobe nearly as long as ischium; merus with groups of short setae on anterior and posterior margins [distal articles unknown].

Pleon. Pleonites: 1-2 (Fig. 11a) with mid-dorsal, posteriorly directed carinate teeth; pleonite 3 lacking carina and tooth. Epimera: 1 and 3 broadly rounded posterodistally, epimeron 2 weakly angular. Pleopod 1 (Fig. 16a): peduncle and rami subequal.

Urosome. Urosomite 1 (Fig. 11a): longest, with inconspicuous short boss close to the posterior margin; urosomites 2 and 3 subequal in length, lacking dorsal projections. Uropod 1 (Fig. 16c): peduncle elongate, lateral margin with dense row of short setae, inner margin with fewer and longer setae; inner ramus 0.7 × length of peduncle, both margins setose; outer ramus 0.9 × inner ramus, lateral margin setose. Uropod 2 (Fig. 16d): peduncle not tapering, both margins with short setae; inner ramus 0.9 × length of peduncle, both margins setose; outer ramus 0.9 × length of inner ramus, lateral margin setose. Uropod 3 (Fig. 16e): peduncle short, about as long as telson; rami subequal, 2.4 × length of peduncle, outer ramus with plumose setae on the lateral margin. Telson (Fig. 16b) tapered, notched 34%.

Distribution.

Chatham Rise, east of New Zealand.

Remarks.

The female specimen has the same antenna 1 morphology as the male: short peduncle articles and numerous flagellum articles. The proximal articles of the flagellum are shorter than wide.