Metaprotella sandalensis Mayer 1898

Metaprotella sandalensis Mayer, 1898

(Fig. 4)

Metaprotella sandalensis Mayer, 1898: 53, figs 1–6. — Mayer, 1903: 40, pl. 1: figs 30, 31, 34–36, pl. 6: figs 56–63, pl. 9: figs 16, 17, 44, 60. — Müller, 1990: 836, figs 41–64. — Laubitz, 1991: 113, fig. 10. — Guerra-García, 2004b: 163, figs 4, 5. — Guerra-García & Takeuchi, 2004: 1017, fig. 37. — Krapp-Schickel & Guerra-García, 2005: 51, fig. 4. — Guerra-García, 2006: 443, fig. 44.

Material examined. More than 20 specimens, AM P61804 (QLD 1570). See station list for occurrences (Lowry & Myers 2009) and Guerra-García (2006) for complete material examined.

Type locality. Sandal Bay, Lifou, Loyalty Islands, New Caledonia.

Description. Based on male, ~ 7.5 mm and female, ~ 5.6 mm, AM P61804.

Head and pereonites slender. Head/pereonite 1 fused (suture present, faintly visible). dorsal margin convex; eye large, distinctive. Antenna 1 well developed; slender, as long or longer than body; peduncle articles 2 and 3 subequal in length, article 3 straight; accessory flagellum absent; flagellum 0.4 x peduncular length, with more than 2 articles, proximal article composed of 2 articles. Antenna 2 0.4 x antenna 1 length, slender; peduncle with several feeble setae; flagellum about 1/5 (0.2 x) of peduncular length, with 2 articles. Mandible right incisor with 5 teeth, right lacinia mobilis absent, accessory setal row with 4 setae; molar well developed; left incisor with 5 teeth, lacinia mobilis with 5 teeth, without trapezoid plate; palp 3–articulate, palp setal formula 1-x-1. Maxilliped inner plate smaller than outer plate, subrectangular; outer plate 2.5 x length of inner plate; palp article 2 scarcely setose on inner margin; palp article 4 not enlarged, falcate.

Pereon. Pereonites 6 and 7 completely fused. Pereonite 1 with small, paired, curved anterodorsal projections. Gnathopod 1 distinctly smaller than gnathopod 2; propodus triangular, palm begins 1/4 along posterior margin, minutely serrate, without large, rounded knob proximally; dactylus slightly curved, inner margin smooth. Pereonite 2 with paired anteriorly curved mid-dorsal projections and simple distal projection dorsally. Gnathopod 2 situated toward anterior end of pereonite 2; basis about 0.75 x length of pereonite 2, with anterodistal projection; ischium without anterodistal projection; propodus subovate, large, anterodistal margin widely concave or straight, without anterodistal triangular projection or projections along mid-anterior margin; palm without proximal cavity filled with membranous sack, proximal projection with 1 robust (grasping) seta, palm margin irregular, smooth, without hook-like projection at base of dactylus, with narrow well developed distal shelf, with two triangular projections distally, with deep, narrow sinus, with large midpalmar projection. Pereonite 3 with paired mid-dorsal projections and distal single projection dorsally. Pereopod 3 reduced, with 1 article. Pereonite 4 without projections. Pereopod 4 reduced, with 1 article. Pereopod 5 well developed, with 7 articles, slender. Pereopods 6 and 7 simple or prehensile (very weakly). Pereopod 6 basis shorter than propodus. Pereopod 7 similar to pereopod 6.

Gills on pereonites 3 and 4. Pereonite 3 gill length less than 1/4 of corresponding pereonite, straight, ovate. Pereonite 4 gill length about 1/8 of corresponding pereonite, straight, ovate.

Pleon. Uropod 1 present; peduncle fused to pleon.

Female (sexually dimorphic characters). Gnathopod 2 palm without sinus.

Habitat. Müller (1990) reported that Metaprotella sandalensis probably prefers sheltered locations. It occurs in mangroves, seagrass beds, coral rubble and on coarse and fine sediment bottoms. In these habitats it is found on algae such as Halimeda and Turbinaria ornata, on hydroids such as Gymnangium sp., Aglaophenia cupressina and Macrorhynchia philippina and it is common on sponges, gorgonians, soft corals, encrusted dead corals, bryozoans and ascidians (Guerra-García 2006).

Remarks. This species is common in shallow waters of the tropical Indo-Pacific and is clearly the most common species on the Great Barrier Reef. The GBR specimens are assigned to Metaprotella sandalensis on the basis of the arrangement of the dorsal projections and the absence of a marked suture between the head and pereonite 1 (Larsen, 1997).

Distribution. Australia. Queensland: Great Detached Reef; Shadwell Reef; GBRMPA Reef 11-102; GBRMPA Reef 11-418; Ashmore Reef; Boot Reef, Portlock Reef; Hervey Islands, Freshwater Bay; Crystal Beach, Coconut Beach, Blue Lagoon, Watsons Bay, and off North Point, Lizard Island; Eagle Island; Osprey Island; Ellison Reef. New South Wales: Elizabeth and Middleton Reefs (Guerra-García 2006). Western Australia: Shark Bay and Cockburn Sound (Guerra-García 2004a). Tasmania: Sloop Reef, Bay of Fires, 41º13’S, 148º17.5’E, Joes Bight, Freycinet Peninsular, 42º16.7’N, 148º18.7’E (Guerra-García & Takeuchi 2004). Fiji Islands. Viti Levu (McCain & Steinberg 1970). Indonesia. Labuan Badjo, Borneo; Dongala, Celebes; Pulu Tongkil and 6º07.5’N 120º26’E, Sulu Sea; Amboina; between Gisser and Ceram-Laut, Ceram Sea (McCain & Steinberg 1970). Bali and Sanur-Bali (Krapp-Schickel & Guerra-García 2005). New Caledonia. Sandal Bay, Lifou, Loyalty Islands (Mayer 1898). Kiribati. Aranuka and Tapeteucea, 4º20’S 152º10W (McCain & Steinberg, 1970). Malaysia. (McCain & Steinberg 1970). Papua New Guinea. Bootless Bay and Madang Lagoon (Guerra-García 2003a). Thailand. Koh Chang and Koh Kahdal (McCain & Steinberg 1970); Phuket (Guerra-García 2004b). Singapore. (McCain & Steinberg 1970). Society Islands. Bora Bora and Moorea, (Müller 1990). Sri Lanka. Dutch Bay (McCain & Steinberg 1970). USA. Hawaii: Oahu and Lisiansky Islands (McCain & Steinberg 1970).