Rhinoecetes wamus, 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 : 123-126

Rhinoecetes wamus sp. nov.

Figures 15–16

Type fixation. Holotype, male, here designated.

Etymology. The species is named after the Western Australian Museum (Perth) for all the help provided to me over many years.

Material examined. Holotype. ♂, 5.5 mm. Western Australia, Cape Range National Park, inshore limestone reef off Ned’s Camp , 22°00’S 113°55’E, 2 m, sand, J.K. Lowry, 31 December 1983, WA-330, AM P34971.

Paratypes. Same sample as holotype, AM P 101864 (> 100 specimens) . Same sample as holotype, WAM C73453 (10 specimens) . Same sample as holotype, NHMD-233151 (5 specimens). Western Australia, Cape Range National Park , 21°59’S 113°54.5’E, 0–1 m, limestone, coral rubble, patches of inshore sediment, H.E. Stoddart, 31 December1983, stn WA-316, AM P35073 (13 specimens) . Western Australia, King George Sound, Ledge Bay , 100 m off beach, 35°00.48’S, 118°00.00’E, hand dredge, depth 2.0 m, GCB Poore, & HM Lew Ton, stn SWA 59, 16 Apr 1986, NMV J63453 (15 specimens and abodes). Western Australia, King George Sound, Ledge Bay , 100 m off beach, 35°00.48’ S, 118°00.00’ E, hand dredge, depth 2.0 m GCB Poore, & HM Lew Ton, stn SWA 59, 16 Apr 1986, NHMD-233159 (1♂ 1♀) .

Additional material. Western Australia, Shark Bay, 30 km south of Carnavon, Bush Bay , 25°10’S 114°39’E, 0.1 m, sand flat, in Dentalium shells, HE Stoddart, JK Lowry, 6 January 1984, stn WA-433, AM P.35138 (3 ♀, 1 ♂) . Western Australia, Shark Bay, 30 km south of Carnavon, Bush Bay , 0.5 km offshore, 25°10’S 114°39’E, 2 m, airlift, sea grass bed, RT Springthorpe, JK Lowry, 6 January 1984, stn WA-431, AM P.34978 (16 specimens) . Bush Bay, 30 km south of Carnarvon , Western Australia, 25°10'S 113°39'E, extensive shallow sand flats, sieved sediment from vicinity of sea grass/algal bed, 0.5 m, H.E. Stoddart, 6 January 1984, stn WA-428, AM P.90671 (40 specimens) . Western Australia, Bush Bay, 30km south of Carnarvon , 0.5 km offshore, 25°10'S 113°39'E, extensive shallow sea grass beds, airlift from branching sea grass, 0.5 m, J.K. Lowry & R.T. Springthorpe, 6 January 1984, stn WA-426, WAM C73454 (7 specimens) . Western Australia, Bush Bay, 30km south of Carnarvon , 25°10'S 113°39'E, extensive shallow sand flats, sieved sand from water's edge, H.E. Stoddart, 6 January 1984, stn WA-425, 0 m, AM P90675 (21 juvenile and young) . Western Australia, Bush Bay, 30km south of Carnarvon , 25°10'S 113°39'E, 0.5 m, extensive shallow sand flats, sieved sediment from vicinity of sea grass/algal bed, H.E. Stoddart, 6 January 1984, stn WA-428, NHMD-233158 (12 specimens) .

Description (♂). Head about as long as pereonites 1 and 0.8 of 2 combined along dorsal midline; mid-anterior depression deep, encompassing approximately 0.7 head length. Rostrum straight, acutely pointed, in dorsal view reaching beyond apices of eye lobes with about 0.75 its length; moderate brows either side of rostrum. Eye lobes in lateral view tapering from broad base, apically rounded, lower distal margin with 1–2 simple setae.

Antenna 1 approximately as long as head and pereonites 1–5, peduncle article 1 with medioproximal setiferous bulge; flagellum of 7+ articles. Antenna 2 about as long as head, pereon and pleon combined, peduncle article 4 with scattered groups of short setae; article 5 length 0.9 of article 4, with 7–8 groups of unequally long setae ventrally; flagellum articles 1 and 2 with many robust setae of moderate length; ventral projection of peduncle article 2 longer than wide (full base width not observed), tapering towards rounded apex, with fringe of about 10 simple setae apically and laterally.

Mouthparts, mandible palp article 1 with 6 ventral and 5 apical long setae.

Gnathopod 1 propodus length 2.9 width, with 4 mid-posterior robust setae. Gnathopod 2 propodus length 1.7 greatest width. Pereopods 3–4 basis with dense row of very long setae along entire anterior margin, lateral surface and posterior margin with a few long setae; merus anterior and apical margins with dense cover of very long setae, posterior margin with 5–6 groups of unequally long setae. Pereopods 5–6 basis anterodistal margin and corner with dense groups of many very long setae.

Uropod 1 peduncle dorsolaterally with 2–3 robust setae and tuft of longer simple setae distally, medioapical corner with single robust seta, ventral apical margin with finely fimbriate corona; outer ramus stout, length approximately 2.5 width, slightly inwardly curved, 0.5 length of peduncle, dorsolaterally with 4 robust setae; inner ramus about 0.8 length of outer ramus, straight, with small accessory robust setae adjacent to terminal robust seta. Uropod 2 peduncle approximately 0.4 length of peduncle of uropod 1, with finely fimbriate corona; ramus 0.5 length of peduncle, reaching beyond uropod 3 ramus with nearly its entire length. Uropod 3 peduncle with short, rounded median projection carrying a few simple setae apically (not shown in Fig. 15 us); ramus with 3–4 long simple setae. Telson apex weakly convex.

Female. Pereopods 3–6 with shorter and less dense setae; uropod 1 peduncle with a few more robust setae.

Pereonite 7 ventrally with long, forward curved sternal papillae ( Fig. 16 F sp).

Remarks. Samples from Bush Bay in Shark Bay is listed as ‘Additional material’ because the few adult males present lack antenna 2. Adult specimens otherwise share the long, dense setae on pereopod 3–6 in males, and similar setal configuration on uropod 1 in both sexes.

Size. Largest ♂, 5.5 mm; largest ♀, 4.5 mm.

Colour. No observations. Abodes. The holotype sample (AM P35138) contained a microvial with 6 micromollusc abodes, 1 with amphipod. The AM P34971 sample (Bush Bay) included 5 very long and slender Dentalium sp. shells, (longest shell 45 mm, shortest 23 mm). It is unclear if a protruding tube has broken off, as none of the 4 specimens from the sample was in a shell, but tube building is indicated in the shell entrance and farther inside.

Distribution. Type locality: Western Australia, Ningaloo at Cape Range, 0– 2 m. Shark Bay (Bush Bay), 0.1 – 2.0 m.

Figures

FIGURE 15. Rhinoecetes wamus sp. nov. Holotype, Ƌ, except F paratype, ♀. a2 flag, antenna 2 flagellum; cdv, cephalon dorsal view; clv, cephalon lateral view; md plp, mandible palp; us, urosome with uropod 1 ventral apical margin enlarged (arrow); vp, antenna 2 article 2 ventral projection. Habitus scale: 1 mm.

FIGURE 16. Rhinoecetes wamus sp. nov. Holotype, ♂, except F paratype, ♀. gp1, gnathopod 1; gp2 gnathopod 2; p3, pereopod 3; p6, pereopod 6; sp, sternal papilla (left lateral view), 6 and 7, pereonites 6 and 7.