Prionalpheus triarticulatus Banner & Banner, 1960

Figures 4, 5 A–C

Prionalpheus triarticulatus Banner & Banner 1960b: 293, fig. 1; Banner & Banner, 1971: 265; Banner & Banner, 1982: 14, fig. 2; Hayashi, 1996: 491, figs. 315d–f, 316, 317d, e; Nomura & Asakura, 1998: 28.

Material examined. French Polynesia, Society Islands. 1 ovigerous female (CL 3.00 mm), FLMNH UF Arthropoda 23091, Moorea, about half-way between Maharepa and airport, 149.7878˚ S, 17.4778˚ W, nearshore reef flat, silt-sand with large coral heads (mostly Porites), under coral heads and large pieces of rubble, hand and dip net, depth: 1–2 m, coll. A. Anker, V. Liao, 09.XII.2009 [fcn BMOO-10334]; 1 ovigerous female (CL 3.65 mm, FLMNH UF Arthropoda 23089, Moorea, Papetoai lagoon, 17.4909˚ S, 149.8829˚ W, lagoon with sand and corals, under coral heads and rubble, hand and dip net, depth: 0.5–1 m, coll. A. Anker, 31.X.2009 [fcn BMOO-7875]; 1 ovigerous female (CL 4.05 mm), OUMNH.ZC.2010-01-002, Moorea, near Papetoai, 17.4911˚ S, 149.8860˚ W, lagoon, fringing reef, sand with coral heads, under coral heads and rubble, hand and dip net, depth: 0.5–1.5 m, coll. A. Anker, 14.XI.2009.

Description. See Banner & Banner (1960b).

Colour pattern. Hyaline-white, semitransparent, with some orange at bases of walking legs; brownorange hepatopancreas visible through carapace; eggs bright purple-red (Fig. 4).

Type locality. Viti Levu, Fiji (Banner & Banner 1960b).

Ecology. All Moorea specimens were collected in the lagoon, on silt-sand bottoms under large coral heads and rubble, at very shallow depths (0.5–2 m); previously reported specimens were found in dead coral heads in the mid-section of a fringing reef or extracted from broken solid reef rocks overgrown with algae, at about 18 m (Banner & Banner 1982).

Distribution. Western Pacific: Viti Levu, Fiji; Lizard Island, Great Barrier Reef, Australia; Kushimoto, Kii Peninsula, Japan (Banner & Banner 1960b, 1971, 1982; Hayashi 1996); first record: Moorea, French Polynesia (present study).

Remarks. All specimens agree well with the description provided by Banner & Banner (1960). See also remarks under the following species.