Orthoprotella australis ( Haswell, 1880 )

Guerra-García, José M. & Lowry, J. K., 2009, Caprellidae *, Zootaxa 2260 (1), pp. 290-327 : 299-301

Orthoprotella australis ( Haswell, 1880)

( Fig. 5 )

Protella australis Haswell, 1880: 276 , pl. 12: fig. 4. — Haswell, 1885: 997, pl. 49: figs 2–4. — Mayer, 1890: 23. Orthoprotella australis . — Mayer, 1903: 35, pl. 1: figs 23, 24, pl. 6, figs 45, 47–49, pl. 9: figs 14, 37, 57. —Guerra-

García, 2004a: 42, fig. 44. —Guerra-García, 2006: 444, fig. 45.

Material examined. More than 20 specimens, AM P61693 ( QLD 1560 ). See station list for occurrences ( Lowry & Myers 2009) and Guerra-García (2006) for complete material examined .

Type locality. Port Jackson , New South Wales, Australia (~ 33º51’S 151º16’E) .

Description. Based on male, 15.02 mm and female, ~ 7.2 mm, AM P61693.

Head and pereonites slender. Head/pereonite 1 fused (suture present), slightly concave along dorsal margin; eye large, distinctive. Antenna 1 well developed; robust, slightly shorter than body length; peduncle article 2 longest, article 3 straight; accessory flagellum absent; flagellum 0.4 x peduncular length, with more than 2 articles, proximal article composed of 3 articles. Antenna 2 0.4 x antenna 1 length, slender; peduncle with several feeble setae; flagellum about 1/6 (0.17 x) of peduncular length, with 2 articles. Labrum notched, forming rounded quadrilateral projections. Mandible right incisor with 5 teeth, right lacinia mobilis transformed into a serrate plate, accessory setal row with 2 setae; molar well developed; left incisor with 5 teeth, lacinia mobilis with 4 teeth, without trapezoid plate, accessory setal row with 3 setae; palp 3–articulate, palp setal formula 1-x-y-1. Maxilla 1 outer plate with 7 stout apical setal-teeth. Maxilliped inner plate smaller than outer plate; oval; 3 x length of inner plate; palp article 2 setose on inner margin; palp article 4 not enlarged, weakly falcate.

Pereon. Pereonites 6 and 7 partially 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 to serrate, without large, rounded knob proximally; dactylus straight, inner margin serrate. Pereonite 2 without projections. Gnathopod 2 situated toward anterior end or near middle of pereonite 2; basis with anterodistal projection; ischium with anterodistal projection; propodus elongate (subrectangular), large, anterodistal margin narrowly concave, without anterodistal triangular projection, without projections along mid-anterior margin; palm without proximal cavity filled with membranous sack, palm proximal projection with 1 robust (grasping) seta, palm margin straight, smooth, without hook-like projection at base of dactylus, with broad well developed distal shelf, with 1 large projection, with deep, narrow sinus, with large midpalmar projection. Pereonite 3 with subacute anterolateral projection. Pereopod 3 reduced, with 1 article. Pereonite 4 without projections. Pereopod 4 very slender. Pereopod 4 reduced, with 1 article Pereopod 5 well developed, with 7 articles. Pereopods 6 and 7 prehensile. Pereopod 7 similar to pereopod 6.

Gills on pereonites 3 and 4. Pereonite 3 gill length about 1/2 of corresponding pereonite, curved anteriorly, ovate. Pereonite 4 gill length about 1/2 of corresponding pereonite, curved anteriorly, ovate or elongate, cylindrical.

Pleon. Uropod 1 present; peduncle free, elongate, length about 2.5 x width; ramus length about 3–4 x width, ramus 1 x peduncular length (about). Uropod 2 ramus absent.

Female (sexually dimorphic characters). Head/pereonite 1 smooth, not rounded dorsally, with paired anteriorly straight dorsal projections. Pereonite 2 without paired midventral projections. Pereonite 3 without anterolateral projection. Gnathopod 2 situated near anterior end of pereonite 2; palm margin slightly convex, minutely serrate. Uropod 2 ramus well developed or absent.

Habitat. Most of the specimens has been found clinging on hydroids ( Macrorhynchia phylippina and Salacia sp. ), but the species is also associated with tunicates ( Polycarpa pigmentata ), sediments and algae (see Guerra-García, 2004a, 2006).

Remarks. Orthoprotella australis is easily distinguished from its congeners by the presence of two acute projections on the head. The species seems to be uncommon on the Great Barrier Reef, but large populations were found on hydroids at Lizard Island.

Distribution. Australia. Queensland: Between Bird Islet & Trawler Beach, Lizard Island; off Chinamans Ridge; Pidgin Point (Guerra-García 2006). Northern Territory: south side of New Year Island, west end Oxley Island, Arafura Sea ( Guerra-García 2004a). Western Australia: 1 km north-east of Cape Legendre, Legendre Island, Dampier Archipielago and North-West shelf ( Guerra-García 2004a). New South Wales: Port Jackson; off Manning River and Port Stephens ( Haswell 1880). Indonesia. Between Gisser and Ceram Laut, Ceram Sea; Pulu Jedan, Arafura Sea; Banda Sea; Sawu Sea ( McCain & Steinberg 1970).

Figures

FIGURE 5. Orthoprotella australis (Haswell, 1880). Lateral view. A, male, ~10.5 mm, B, female, ~7.2 mm, AM P61693, between Bird Islet and South Island, Lizard Island, Great Barrier Reef. Refigured from Guerra-García (2006).