Rhinoecetes lowryi, Just, 2019

Just, Jean, 2019, Siphonoecetini Just, 1983 (Crustacea, Amphipoda, Ischyroceridae) 13: Western Australian species of Bubocorophiina in Rhinoecetes, Cephaloecetes, Sinoecetes, Borneoecetes and Pararhinoecetes gen. nov., Zootaxa 4554 (1), pp. 101-140 : 114-116

Rhinoecetes lowryi sp. nov.

Figures 9–10

Type fixation. Holotype, ♂, here designated.

Etymology. The species is named for my old friend Jim Lowry who collected the specimens, and for his enormous contribution to Australian and world amphipodology.

Material examined. Holotype, ♂, 4.4 mm. Off Green Is., Rottnest Is., Western Australia, 32°01’S 115°30’E, 14 m, fine sand, stn WA-236, J.K. Lowry, 21 December 1983, AM P 101862 .

Paratypes. Same sample as holotype, AM P 101863 (3 specimens) .

Description (♂, all parts of antenna 2 beyond peduncle article 3 missing in all specimens). Head as long as pereonites 1 and 2 combined along dorsal midline; mid-anterior depression weak, encompassing about 0.4 head length. Rostrum straight, acutely pointed, in dorsal view reaching beyond apices of eye lobes with about half length. Eye lobes in lateral view apically truncate, lower distal margin with a few short, simple setae; in dorsal view eyelobes acutely pointed.

Antenna 1 approximately as long as head and pereonites 1–4 and half of 5 combined; flagellum of 5+ articles, as long as peduncle articles 2 and 3 combined. Antenna 2 ventral projection of peduncle article 2 approximately 1.5 times longer than broad at base, with nearly parallel margins, apex rounded, with short fringe of long simple setae laterally and apically;

Mouthparts, mandible palp article 1 with 4 lateral, 3–4 medial and 4 apical setae of varying length.

Gnathopod 1 propodus length 3.0 width, with 3 mid-posterior robust setae. Gnathopod 2 propodus length 1.7 greatest width. Pereopods 3–4 basis with sequentially long and short setae along anterior margin, group of long setae in distal half of posterior margin; merus with a few short mid-anterior setae and tuft of longer anterodistal setae, posterior margin with irregular groups of unequally long setae. Pereopods 5–6 basis with a few short setae in anterodistal corner, posterior margin with a few short setae.

Uropod 1 peduncle dorsolaterally with row of 5–6 robust setae, 1–2 simple seta proximally, and tuft of short setae distally, mediodistal corner with single robust seta, ventral apical margin with finely fimbriate corona; outer ramus slightly inwardly curved, approximately 0.6 dorsal length of peduncle, lateral margin with 3–4 robust setae, dorsomedial with row of simple setae; inner ramus 0.7 length of outer ramus, straight, lateral margin with row of simple setae. Uropod 2 reaching just beyond uropod 3 ramus, peduncle approximately 0.4 length of peduncle of uropod 1, with finely fimbriate corona, lateral margin with single simple seta; ramus 0.8 length of peduncle, 0.8 length of uropod 1 inner ramus, lateral margin with 2 simple setae, medioapical corner with single simple seta alongside terminal robust seta. Uropod 3 peduncle with rounded median projection carrying a few simple setae apically (not illustrated); ramus with 4–5 simple setae. Telson width approximately 1.3 length, apex straight to slightly concave.

Female. Not known.

Size. Largest ♂, 4.4 mm.

Colour and biology. No observations.

Distribution. Western Australia, Rottnest Island, 14 m.

Remarks. Rhinoecetes lowryi is the only Western Australian species with simple setae on the inner ramus of uropod 1 and on uropod 2 ramus in addition to the terminal long robust seta.

Figures

FIGURE 9. Rhinoecetes lowryi sp. nov. Holotype, ♂, except M, ♂, paratype. cdv, cephalon dorsal view; clv, cephalon lateral view; md plp, mandible palp; vp, ventral projection of article 2 of antenna 2. Scale for habitus: 1 mm.

FIGURE 10. Rhinoecetes lowryi sp. nov. Holotype, ♂, except M, ♂, paratype. gp1, gnathopod 1; gp2, gnathopod 2; p4, pereopod 4; p6, pereopod 6; us, urosome; up1 vv, uropod 1 peduncle ventral apical margin.