Perotripus keablei Guerra-García, 2006

Guerra-García, José M. & Lowry, J. K., 2009, Caprellidae *, Zootaxa 2260 (1), pp. 290-327 : 315-317

Perotripus keablei Guerra-García, 2006

( Fig. 13 )

Perotripus keablei Guerra-García, 2006: 431 , figs 24–27.

Material examined. Holotype male, 5.2 mm, AM P61747 ( QLD 6 ) . Paratypes: 1 female, AM P61748 ( QLD 14 ). See station list for occurrences ( Lowry & Myers 2009) and Guerra-García (2006) for complete material examined .

Type locality. Off Mangrove Beach, Blue Lagoon, Lizard Island , Queensland (14º40’S 145º28’E), sand, 1.5 m depth .

Description. Based on holotype male, 5.2 mm and female paratype, 2.7 mm.

Head and pereonites slender. Head/pereonite 1 fused (suture almost absent); dorsal margin convex; eye large, distinctive. Antenna 1 reduced; slender, 0.15 x body length; peduncle article 2 longest, article 3 straight; accessory flagellum absent; flagellum 0.33 x peduncular length, with 2 articles. Antenna 2 0.6 x antenna 1 length, slender; peduncle with several feeble setae; flagellum about 1/5 (0.2 x) of peduncular length, with 2 articles. Labrum notched, forming rounded quadrilateral projections. Mandible right incisor with 6 teeth, right lacinia mobilis transformed into a plate, followed by 4 plates decreasing in size, accessory setal row absent; molar absent; left incisor with 6 teeth, lacinia mobilis with 6 teeth, with 3 trapezoid plates decreasing in size; palp 3–articulate, palp setal formula with 1 to 4 large distal setae. Maxilla 1 outer plate with 5 stout apical setal-teeth. Maxilliped inner plate subequal to outer plate, subrectangular; outer plate 2/3 (0.66 x) length of inner plate; palp article 2 setose on inner margin; palp article 4 not enlarged, not falcate.

Pereon. Pereonites 2 to 7 not fused. Pereonite 1 without projections. Gnathopod 1 distinctly smaller than gnathopod 2; propodus subtriangular, palm begins about 1/3 along posterior margin, smooth, without large, rounded knob proximally; dactylus curved, inner margin smooth. Pereonite 2 without ventral projection between insertion of gnathopods. Gnathopod 2 situated toward anterior end of pereonite 2; basis about 0.5 x length of pereonite 2, without anterodistal projection; ischium without anterodistal projection; propodus elliptical, large, anterodistal margin narrowly concave, without anterodistal triangular projection, without projections along mid-anterior margin; palm without proximal cavity filled with membranous sack, proximal projection with 3 robust (grasping) setae, margin convex, minutely serrate, without hook-like projection at base of dactylus, without distal shelf, sinus or midpalmar projection. Pereonite 3 without projections. Pereopod 3 reduced, with 1 article. Pereonite 4 without projections. Pereopod 4 reduced, with 1 article. Pereopod 5 reduced or vestigial, with 3 slender articles. Pereopods 6 and 7 simple. Pereopod 6 basis shorter than propodus. Pereopod 7 similar to pereopod 6.

Gills on pereonites 2 to 4. Pereonite 3 gill length about 1/4 of corresponding pereonite, straight, ovate. Pereonite 4 gill length about 1/8 of corresponding pereonite, curved anteriorly, ovate.

Pleon. Uropods absent.

Female (sexually dimorphic characters). Pereonites 4–6 shorter than in male; propodus of gnathopod 2 twice as long as wide. Oostegites sparsely setose. Pereopod 6 palm without robust setae.

Habitat. Sandy bottoms, coral rubble, 0.5 to 25 m depth.

Remarks. The only other known species of Perotripus is P. brevis ( La Follette, 1915) from the west coast of North America, redescribed in detail by Laubitz (1970). Perotripus keablei differs from P. brevis as follows: pereonites 2 and 3 are smooth instead of sculptured with lateral projections; pereopod 3 uniarticulate instead of three–articulate; the penes are large instead of small; the pleon lacks a pair of small appendages.

Distribution. Australia: Queensland: Blue Lagoon; Casuarina Beach; Mermaid Cove, all Lizard Island (Guerra-García, 2006).

Figures

FIGURE 13. Perotripus keablei Guerra-García, 2006. A, holotype male, 5.2 mm, AM P61747, Mangrove Beach, Lizard Island, B, paratype female, 2.7 mm, AM P61748, Bird Islet, Lizard Island, Great Barrier Reef. Refigured from Guerra- García (2006).