Belkginoecetes springthorpei, Just, Jean, 2012

Just, Jean, 2012, Siphonoecetini Just, 1983 (Crustacea, Amphipoda, Ischyroceridae) 10: Belkginoecetes gen. nov., Tropicoecetes gen. nov. and Rhinoecetes Just, 1983 from north-eastern and northern Australian shallow water, with eight new species, Zootaxa 3528, pp. 1-28 : 9

Belkginoecetes springthorpei sp. nov.

Figures 4–5

Type fixation. Holotype, male, here designated.

Etymology. The species is named for my friend Roger T. Springthorpe, Technical Officer, Marine Invertebrates, Australian Museum, who shared this somewhat unpleasant dive with me, and assisted me up and down the coast of Queensland.

Material examined. Holotype, 3, 3.3 mm, Airlie Beach, Queensland, Australia, 20°16’S, 148°43’E, 2 m (LW), fine detrital mud with some content of foraminifera and small shell fragments, hand dredge, J. Just, R.T. Springthorpe, stn AU40, 23 July 1984, QM W29155.

Paratypes. Same data as holotype, QM W29156 (ƤA, ovigerous). Same data as holotype, QM W29157 (23 specimens, various sizes, 16 abodes, 5 occupied).

Description (holotype, 3). Head as long as pereonites 1 and 2 combined along dorsal midline. Rostrum nearly straight, slightly down curved at apex, acutely pointed; in dorsal view reaching beyond apices of eye lobes with about half its length. Eye lobes rounded in lateral view, lower anterior margin with single simple seta.

Antenna 1 approximately as long as head and pereonites 1–5 combined, reaching to apex of antenna 2 peduncle article 4; flagellum of 6+ articles, approximately as long as peduncle articles 2 and 3 and half of 1 combined. Antenna 2 slightly longer than entire body from head to telson ; ventral projection of peduncle article 2 base width 2/3 greatest length, tapering, rounded distally, with fringe of long setae laterally and apically; articles 3–5 with many dorsal, ventral and ventrolateral groups of short simple setae; article 5 length 0.88 of 4; flagellum articles 1 and 2 robust setae shorter than or slightly longer that flagellar width.

Mouthparts, mandible palp article 1 with 2 dorsal, 2 ventral and 2 apical long setae.

Gnathopod 1 propodus length 3.2 width, with 3 midposterior robust setae. Gnathopod 2 propodus length 1.9 greatest width. Pereopods 3–4 basis with open row of long setae on anterior margin, a few long setae on lateral surface and on midposterior margin; merus with single midanterior group of long setae, with groups of long setae along posterior margin. Pereopods 5–6 basis with row of long setae along distal half of anterior margin, posterior margins with a few unequally long setae.

Uropod 1 peduncle with 2 small dorsolateral robust setae; outer ramus 4 times longer than wide, approximately 0.5 length of peduncle, lateral margin with 2 robust setae, submedially with single dorsal simple seta; inner ramus 0.9 length of outer ramus, slightly tapering towards apex. Uropod 3 reaching beyond telson with 1/3 its length, distolaterally with 2 long simple setae, mediodistally with 2 short simple setae. Telson of equal width and length, apex broadly convex.

Female. Uropod 1 peduncle and outer ramus with many more robust setae than in male ( Fig. 5 Fus), number of setae increasing with size of specimen. Pereonite 7 ventrally with short, broadly rounded sternal papillae ( Fig. 5 Fsp).

Size. Largest 3, 3.3 mm; largest Ƥ (ovigerous), 3.2 mm.

Colour and biology. Body faintly brownish to light sandy mottled. In larger specimens pereonite 1 with brown bar across dorsally extending onto coxal plate 1, also on coxal plate 2. Eyes white with black ocelles. Frons creamwhite; upper lip purple-brown. Antenna 1 faintly purple-brown. Antenna 2 flagellum colourless, peduncle whitesandy-mottled, article 4 with proximal purple brown ring. Specimens occupy microprosobranch shells and occasionally polychaete tubes.

Distribution. Airlie Beach, Queensland, Eastern Australia, 2 m.

Figures

FIGURE 4. Belkginoecetes springthorpei gen. et sp. nov. Holotype 3, except F, paratype Ƥ. a 2 flag, antenna 2 flagellum; c dv and c lv, head dorsal and lateral views; tel, telson; up 3, uropod 3; us lv, urosome lateral view; vp, ventral projection of article 2 of antenna 2. Habitus scale: 1 mm.

FIGURE 5. Belkginoecetes springthorpei gen. et sp. nov. Holotype, 3, except F, paratype, ovigerous Ƥ. gp 1 and gp 2, gnathopods 1 and 2; md plp, mandible palp; p 3 and p 5, pereopods 3 and 5; sp, sternal papillum (right lateral view); us, urosome; 6 and 7, pereonites 6 and 7.