Rhinoecetes albomaculosus, Just, Jean, 2012

Just, Jean, 2012, Siphonoecetini Just, 1983 (Crustacea, Amphipoda, Ischyroceridae) 9: New species in Rhinoecetes Just, 1983, Cephaloecetes gen. nov. and Neoecetes gen. nov. from the south-eastern Australian shelf, Zootaxa 3234, pp. 1-42 : 29-33

Rhinoecetes albomaculosus sp. nov.

Figures 18 , 19

Type fixation. Holotype, 3, here designated.

Etymology. The epithet includes the Latin albus (white) and maculosus (spotted) alluding to the white spots on antenna 2 in live specimens.

Material examined. Holotype, 3, 5.8 mm, Off Moona Moona Creek, south east of Huskisson, Jervis Bay, New South Wales, Australia, 35°03’S, 150°40’E, 8 m, muddy sand, hand dredge, SCUBA. J. Just, P.B. Berents, R.T. Springthorpe, 15 November 1984, stn AU63, AM P87051.

Paratypes. Jervis Bay, New South Wales: Same data as holotype 1 Ƥ, illustrated), AM P87052. Off Moona Moona Creek, south east of Huskisson, 35°03’S, 150°40’E, 8 m, broadly rippled fine sand with some detritus, hand dredge, SCUBA. J. Just, P.B. Berents & R.T. Springthorpe, 15 November 1984, stn AU 62, AM P87053 (around 100 specimens). Off Moona Moona Creek, south east of Huskisson, 35°03’S, 150°40’E, 8 m, broadly rippled sand with detritus, hand dredge, SCUBA. J. Just, P.B. Berents & R.T. Springthorpe, 15 November 1984, stn AU 64, AM P87054 (2 specimens). Off Moona Moona Creek, south east of Huskisson, 35°03’S, 150°40’E, 8 m, broadly rippled sand with some detritus, hand dredge, SCUBA. J. Just, P.B. Berents & R.T. Springthorpe, 16 November 1984, stn AU66, AM P87055 (18 specimens). Off Moona Moona Creek, south east of Huskisson, 35°03’S, 150°40’E, 8 m, fine sand with detritus along inner edge of low rock reef patch, hand dredge, SCUBA. J. Just, P.B. Berents & R.T. Springthorpe, 16 November 1984, stn AU67, AM P87056 (21 specimens plus 39 in abodes). Off Moona Moona Creek, south east of Huskisson, 35°03’S, 150°40’E, 8 m, fine sand with detritus along inner edge of low rock reef patch, hand dredge, SCUBA. J. Just, P.B. Berents & R.T. Springthorpe, 16 November 1984, stn AU68, AM P87057 (34 specimens, many in abodes mostly polychaete tubes). Off Moona Moona Creek, south east of Huskisson, 35°03’S, 150°40’E, 14m, silty sand with fine shell fragments, hand dredge, SCUBA. J. Just, P.B. Berents & R.T. Springthorpe, 18 November 1984, stn AU74, AM P87058 (40 specimens, many in abodes mostly polychaete tubes). South of Moona Moona Creek, south east of Huskisson, 35°03’S, 150°40’E, 5.5m, broadly rippled sand with some detritus, hand dredge, SCUBA. J. Just, P.B. Berents & R.T. Springthorpe, 17 November 1984, stn AU75, AM P87059 (> 50, many in abodes). Off Moona Moona Creek, south east of Huskisson, 35°03’S, 150°40’E, 14 m, silty sand with fine shell fragments, hand dredge, SCUBA. J. Just, P.B. Berents & R.T. Springthorpe, 18 November 1984, stn AU76, AM P87060 (23 specimens, some in abodes). Eden, New South Wales: N of Fisheries Beach, East Boyd Bay, 37°04’S, 149°55’E, 4.3 m, pipe dredge, S. Keable and P. Albertson, 22 February 1985, AM P36295 (1 specimen). N of Fisheries Beach, East Boyd Bay, 37°04’S, 149°55’E, 4.3 m, pipe dredge, S. Keable and P. Albertson, 21 February 1985, AM P36296 (1 specimen). Off Aislings Beach, Calle Calle Bay, 37°04’S, 149°55’E, 16 m, pipe dredge, S. Keable and P. Albertson, 21 February 1985, AM P36297 (1 specimen). NE of Boydtown Beach, Nullica Bay, 37°04’S, 149°55’E, 9 m, pipe dredge, S. Keable and P. Albertson, 21 February 1985, AM P36299 (1 specimen). SE of Legges Beach, Quarantine Bay, 37°04’S, 149°55’E, 11 m, pipe dredge, S. Keable and P. Albertson, 22 February 1985, AM P36300 (1 specimen). Fisheries Beach, East Boyd Bay, 37°04’S, 149°55’E, 11 m, pipe dredge, S. Keable and P. Albertson, 22 February 1985, AM P36302 (1 Ƥ). NE of Tararago Point, Two Fold Bay, 37°04’S, 149°55’E, 17 m, pipe dredge, S. Keable and P. Albertson, 22 February 1985, AM P36301 (1 Ƥ).

Bass Strait, Victoria: 40°03’S, 143°24’E, 122 m, coarse sand, gravel, mud, Smith-McIntyre grab, stn BSS 85, 11 October 1980, NMV J9570 (1 3, 1 young). 40°06’, 143°18’E, 123 m, sand, gravel, mud, Smith-McIntyre grab, stn BSS 98, 11 October 1980, NMV J9571 (2 young). 38°39.8’S, 144°18.2’E, 79 m, fine sand, epibenthic sled, stn BSS 181, 19 November 1981, NMV J9572 (1 young). 39°49.0’S, 143°24.0’E, 56 m, fine sand, Smith-McIntyre grab, stn BSS 184, 20 November 1981, NMV J9574 (1 young). 40°00.7’S, 143°49.9’E, 46 m, fine sand, Smith- McIntyre grab, stn BSS 197, 21 November 1981, NMV J9576 (1 3). 39°49.0’S, 143°24.0’E, 56 m, fine sand, Smith-McIntyre grab, stn BSS 184, 20 November 1981, NMV J62569 (1 3).

Description (holotype, 3). Head as long as pereonite 1 and 3/4 of 2 combined along dorsal midline; brows narrow; midanterior depression shallow, encompassing approximately 1/3 head length. Rostrum in dorsal view straight, narrow, acutely pointed, reaching beyond apices of eye lobes with about its entire length, in lateral view slightly downward pointing. Eye lobes rounded in lateral view, lower anterior margin with a single simple seta. Head and pereon with scattered small simple setae.

Antenna 1 approximately as long as head, pereonites 1–3 combined, reaching to middle of antenna 2 peduncle article 4; flagellum of 5+ articles, approximately as long as peduncle articles 1 and half of 2 combined. Antenna 2 approximately as long as head, pereonites 1–7, pleonites 1–2 and half of 3 combined; ventral projection of peduncle article 2 length about 1.4 width at base, triangular with rounded apex, with fringe of long and short simple setae apically and laterally; article 5 length 0.9 of 4; flagellum articles 1 and 2 with medium length robust setae.

Mouthparts, mandible palp article 1with 2 dorsal, 2 ventral and 2 apical groups (some of single seta) of long setae.

Gnathopod 1 length 2.7 width, with 3 midposterior robust setae. Gnathopod 2 propodus length 1.9 greatest width. Pereopods 3–4 basis with fringe of unequally long setae on anterior margin, a short row of long setae in middle of posterior margin, and a few long setae on distolateral surface. Pereopods 5–6 basis with a few unequally long setae on anterior and posterior margins, with anterodistal tuft of long setae. Pereopod 7 propodus anterior margin with 2 groups of long setae and anterodistal tuft of long setae.

Uropod 1 peduncle with dorsolateral row of a few small robust setae and a few simple setae, mediodistal corner with single robust setae; outer ramus nearly straight, 0.6 length of peduncle, lateral margin with row of 2–4 small robust setae, medial margin with small simple setae, inner ramus 0.6 length of outer ramus, straight, smooth. Uropod 2 peduncle approximately half length peduncle of uropod 1, without setae; ramus 0.5 length of peduncle, nearly straight, smooth except for robust seta apically, reaching beyond ramus uropod 3 with about half its length. Uropod 3 peduncle with rounded median projection carrying a few small simple setae; ramus with crescent of 6–8 short and long simple setae. Telson width approximately 1.2 length, distal margin broadly rounded.

Female. Antenna 1 slightly longer relative to antenna 2 article 4. Antenna 2 sparsely setiferous, less strongly coloured than in males. Sternal papillae short, length approximately 0.75 width at base, forward pointing, apex broadly rounded.

Size. Largest 3, 6.7 mm; largest Ƥ, 5.0 mm.

Variation. A few specimens lack robust setae on the lateral margin of uropod 1 outer ramus. Instead they have a complete row of stout simple setae.

Colour and biology. Head and body semi transparent with light brownish mottling; head with some reddishbrown and while streaks; pereonites 3 and 4 with weak whitish saddle. Antenna 1 generally colourless, articles with terminal white blotches, peduncle article 1 also with reddish blotches. Antenna 2 milky semi transparent, peduncle article 3 with medial white stripe, articles 4 and 5 with white terminal ring, medial face of article 4 with 1–3 (mostly 2) large white spots, more pronounced in males. Abodes comprise micro molluscs, polychaete tubes and bivalve shells ( Fig. 18 A).

Distribution. Jervis Bay, Australia, New South Wales; 5.5– 14 m.

Figures

FIGURE 18. Rhinoecetes albomaculosus sp. nov. Holotype, 3, except A, paratype 3 in abode, and F, paratype Ƥ of 4.6 mm. a 2 flag, antenna 2 flagellum; c, head (dv, dorsal view, lv, lateral view); sp, sternal papillae; 6 and 7, pereonites 6 and 7. Scale bar: 1 mm (3 habitus and Ƥ head with antenna 2 to scale).

FIGURE 19. Rhinoecetes albomaculosus sp. nov. Holotype, 3. gp 1 – 2, gnathopods 1 and 2; md, mandible (left); p 3 and p 6, pereopods 3 and 6; us, urosome with uropods.