Epimeria sophie, Lörz, Anne-Nina & Coleman, Charles Oliver, 2014

Lörz, Anne-Nina & Coleman, Charles Oliver, 2014, Amazing new Amphipoda (Crustacea, Epimeriidae) from New Zealand’s deep-sea, Zootaxa 3838 (4), pp. 423-434 : 424-432

Epimeria sophie sp. nov.

( Figs 2–6 )

Type material. Holotype: NIWA 85463, gravid female 27.8 mm, New Zealand, Chatham Rise (44.777666°S, 174.133°E to 44.782666°S, 174.1385°E), 821–823 m, beam trawl, TAN1116/58, 0 9 November 2011. Paratype: NIWA 85464, juvenile from marsupium of holotype, 6.2 mm, same data as holotype. Etymology. Epimeria sophie sp. nov. is dedicated to Sophie Charlotte, daughter of the senior author. The species epithet is used as a noun in apposition.

Description. Rostrum as long as head, reaching distal margin of the first article of antenna 1; eye present, oval, 0.5 × head height. Pereonite 1 subequal in length to head (excluding rostrum), pereonite 2 c. 0.8 × length of 1, pereonites 1–6 lacking mid-dorsal or dorsolateral processes, but pereonite segments 3–6 posteriorly elevated; pereonite 7 carinate; pleonites 1–3 in lateral view with double carinae. Pleonites and pereonites laterally smooth. Epimeron 1 antero- and posteroventral angle rounded; epimeron 2 similar to 1, posteroventral angle less rounded; epimeron 3 posteroventral angle produced and pointed.

Urosomite 1 with a keel-like mid-dorsal process; urosomite 2 shortest, lacking dorsal process; urosomite 3 lacking mid-dorsal processes.

Antenna 1 peduncle length ratios approximately 3:2:1; accessory flagellum scale-like; primary flagellum of 37 articles. Antenna 2 peduncular articles 1–3 bearing distal processes, flagellum of 34 articles.

Labrum with several terminal setae and slightly dentate at both sides of depression. Mandible incisor and lacinia mobilis strongly dentate; molar produced and triturative; palp article 3 densely setose medially, with 3 long plumose setae distally; palp article 2 with 4 smooth and 1 plumose seta distally. Maxilla 1 inner plate subtriangular, obliquely convex inner margin with 9 stout, plumose setae; outer plate distal margin oblique, with 11 medially lobate robust setae; palp exceeding outer plate; palp article 1 short, article 2 slightly curved medially with stout setae distomedially, stout setae distally. Maxilla 2 with long, distally crenulate setae distally on lateral and medial plates. Maxilliped outer plate broadly rounded distally, reaching mid-length of second article of maxillipedal palp, inner plate with row of slendersetae on medial, anterior face; palp medial margin strongly setose; propodus with several plumose setae at terminal end, reaching length of dactylus.

Pereopods: Gnathopod 1 coxa slender and ventrally truncate; basis linear, slender, both margins with numerous fine setae; merus slightly longer than ischium, anterior margin very short, distal margin oblique, posterodistal angle acute, setose; carpus linear, posterior margin with groups of long setae, anterior margin naked except for long setae at distal end; propodus anterior margin with few short setae, palm finely crenulate, slightly oblique, with cluster of robust setae defining rounded distal margin, posterior margin with 5 groups of long setae; dactylus slender, slightly curved, posterior margin strongly serrate. Gnathopod 2 coxa slightly wider than coxa 1, rounded ventrally; basis linear; ischium to dactylus very similar to gnathopod 1, except propodus slightly longer in gnathopod 2; oostegite on gnathopod 2 longer than basis and longer than gill. Pereopod 3 coxa larger than coxa 2, with midlateral ridge, basis linear, merus slightly expanded distally, carpus slightly shorter than merus, anterior margin naked, posterior margin with 5 pairs of robust setae; propodus naked anteriorly, posterior margin with 6 pairs of robust setae; dactylus stout, curved. Pereopod 4 coxa longer than coxae 1–3, anterior margin straight, produced into posterodistal cusp directed posterodistally, posterior margin divided at mid-point by subacute cusp into two concave sections; basis to dactylus as for pereopod 3. Pereopod 5 coxa subrectangular, posterodistal corner produced; posterior margin straight; basis with a depression mid posterior margin; merus constricted proximally; carpus linear; propodus linear, anterior margin with 3 pairs of robust setae; dactylus curved, stout, c. 0.3 × propodus length. Pereopod 6 coxa with posteriorly rounded, strongly sculptured by ridges; basis expanded dorsoposteriorly, anterior margin with setae; ischium with robust anteroventral setae, merus linear and smooth; carpus and propodus linear with 5 pairs of robust setae each; dactylus curved.

Pereopod 7 coxa small; basis broader than pereopod 5 or 6, anterior margin with setae; ischium to dactylus similar to pereopod 6.

Pleopods 1–3 similar; peduncle broad with few plumose setae lateromarginally, 2 coupling hooks; inner ramus slightly shorter than outer; rami articulated: each article with 1 long plumose setae medially and laterally.

Urosome and telson: Uropod 1 peduncle subequal in length to inner ramus, medial margin with 1 robust seta distally; inner ramus lateral margin with spaced row of short robust setae, medial margin with sparse robust setae; outer ramus marginally shorter than inner. Uropod 2 peduncle with one small setae medially and one seta each side of distal margin, about 0.7 × length of inner ramus; outer ramus two thirds length of inner ramus; both margins of both rami with robust setae. Uropod 3 peduncle short, c. 0.4 × length of inner ramus, medial and inner margins of both rami with sparse row of short robust setae. Telson 1.5 × longer than wide, with u-shaped distal emargination 0.2 × telson length, lobes triangular, broadly rounded apically.

Distribution. Chatham Rise, New Zealand, 821– 823 m.

Figures

FIGURE 2. Epimeria sophie sp. nov. holotype, 27.8 mm, NIWA 85463, habitus, scale bar: 1 mm.

FIGURE 3. Epimeria sophie sp. nov. holotype, 27.8 mm, NIWA 85463; a) antenna 1; b) antenna 2; c) labrum; d) maxilla 1. Scale bars: a – b) 1 mm; c – d) 0.5 mm.

FIGURE 4. Epimeria sophie sp. nov. holotype, 27.8 mm, NIWA 85463; a) maxilliped; b) maxilla 2; c) mandible. Scale bars: a – c) 0.5 mm.

FIGURE 5. Epimeria sophie sp. nov. holotype, 27. 8 mm, NIWA 85463; a) gnathopod 1; b) gnathopod 2; c) pereopod 3; d) pereopod 4, e) coxa 5. Scale bars: a – b) 0.5 mm; c – e) 1 mm.

FIGURE 6. Epimeria sophie sp. nov. holotype, 27. 8 mm, NIWA 85463; a) pereopod 5; b) pereopod 6; c) pereopod 7); d) uropod 1; e) pleopod 2; f) uropod 2; g) uropod 2; h) uropod 3; i) uropod 3; j) telson. Scale bars: a – i) 0.5 mm; j) 0.5 mm.