Quadrisegmentum lowryi Guerra-Garcia 2006
Creators: name: Guerra-García, José M.
name: Lowry, J. K.
Publisher: name: Zenodo
Year: 2009
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Amphipoda
Caprellidae
Quadrisegmentum
Quadrisegmentum lowryi

description: <i>Quadrisegmentum lowryi</i> Guerra-García, 2006 (Fig. 16) <i>Quadrisegmentum lowryi</i> Guerra-García, 2006: 437, figs 34–38. <b>Material examined.</b> Holotype male, 6.2 mm, AM P61635 (QLD 674). Paratypes: 1 female, AM P61636 (QLD 674). See station list for occurrences (Lowry &amp; Myers 2009) and Guerra-García (2006) for complete material examined. <b>Type locality.</b> Inside the Outer Barrier, south-east of Cape York, Queensland (10º56.90’S 144º 0.51’E), coral rubble, 20 m depth (QLD 674). <b>Description.</b> Based on holotype male, 6.2 mm, AM P61635 paratype female, 3.8 mm, AM P61636. <b>Head</b> and pereonites slender. <i>Head/pereonite 1</i> fused (suture absent) concave along dorsal margin or dorsal margin straight; eye large, distinctive. <i>Antenna 1</i> well developed; slender, as long or longer than body; peduncle articles 2 and 3 subequal in length, article 3 straight; accessory flagellum absent; flagellum subequal in length to peduncle, with more than 2 articles. <i>Antenna 2</i> 0.5 x antenna 1 length, slender; peduncle without setae; flagellum 0.75 x peduncular length, with more than 4 articles. <i>Labrum</i> notched, forming rounded quadrilateral projections (very rounded). <i>Mandible</i> right incisor with 5 teeth, right lacinia mobilis absent, three plates accessory setal row with 3 setae; molar absent; left incisor with 5 teeth, lacinia mobilis with 4 teeth, with 3 trapezoid plates decreasing in size, accessory setal row with three setae; palp 3–articulate, palp setal formula 1-0-1. <i>Maxilla 1</i> outer plate with 6 stout apical setal-teeth. <i>Maxilliped</i> inner plate larger than outer plate; subrectangular; outer plate 2/3 (0.66 x) length of inner plate; palp article 2 scarcely setose on inner margin; palp article 4 not enlarged, falcate. <b>Pereon</b>. Pereonites 2 to 7 not fused; pereonite 5 longest. <i>Pereonite 1</i> without projections. <i>Gnathopod 1</i> distinctly smaller than gnathopod 2; propodus subtriangular, palm begins 2/5 along posterior margin, smooth, without large, rounded knob proximally; dactylus slightly curved, inner margin smooth. <i>Pereonite 2</i> with small mid-dorsal hump. <i>Gnathopod 2</i> situated toward anterior end of pereonite 2; basis greater than 2 x length of pereonite 2, without anterodistal projection; ischium without anterodistal projection; propodus subovate, massive, anterodistal margin straight, without anterodistal triangular projection, without projections along mid-anterior margin; palm with proximal cavity filled with a membranous sack, palm proximal projection with 1 robust (grasping) seta, palm margin straight or irregular (slightly), smooth, without hook-like projection at base of dactylus, without distal shelf, without sinus, without midpalmar projection. <i>Pereonite 3</i> without projections. <i>Pereopod 3</i> well developed, with 6 articles. <i>Pereonite 4</i> without projections. <i>Pereopod 4</i> well developed, with 6 articles. <i>Pereopod 5</i> reduced or vestigial, with 4 slender articles. Pereopods 6 and 7 simple. <i>Pereopod 6</i> basis longest followed by merus. <i>Pereopod 7</i> similar to pereopod 6. <i>Gills</i> on pereonites 2 to 4. <i>Pereonite 2 gill</i> triangular, <i>pereonite 3 gill</i> length about 1/3 of corresponding pereonite, straight, elongate, cylindrical. <i>Pereonite 4 gill</i> length about 1/3 of corresponding pereonite, straight, elongate, cylindrical. <b>Pleon</b>. <i>Uropod 1</i> present. <i>Uropod 2</i> ramus well developed. <b>Female</b> (sexually dimorphic characters). <i>Antenna 1</i> flagellum 7–articulate; <i>Antenna 2</i> flagellum 3– articulate. <i>Gnathopod 2</i> carpus about 3 x as long as wide, more elongate than in male, with 3 robust (grasping) setae and without membranous sack proximally. <i>Pereopods 6 and 7</i> 6–articulate, propodus with 4 robust (grasping) setae and 1 seta on pereopod 6 and 3 robust (grasping) setae and 1 seta on pereopod 7. <i>Oostegites</i> not setose. <b>Habitat.</b> Coral rubble, 8 to 20 m depth. <b>Remarks.</b> <i>Quadrisegmentum lowryi</i> is very similar to its only congener <i>Q. triangulum</i>. The main differences between the two species are: (1) the antennae, gnathopods and pereopods 6 and 7 are clearly longer in <i>Q. lowryi</i>; (2) the propodus of the gnathopod 2 male is provided with a developed distal triangular projection in <i>Q. triangulum</i> while this projection is absent in <i>Q. lowryi</i>; (3) the abdominal appendages are 2– articulate in <i>Q. triangulum</i> and 1–articulate in <i>Q. lowryi</i>. Besides these differences, the membranous sack present on the male propodus palm of <i>Q. lowryi</i> is apparently not present in <i>Q. triangulum</i> (Hirayama, 1988). <b>Distribution.</b> <i>Australia</i>. Queensland: south-east of Cape York and Palfrey and South Islands, Lizard Island (Guerra-García 2006).
description: Published as part of <i>Guerra-García, José M. &amp; Lowry, J. K., 2009, Caprellidae *, pp. 290-327 in Zootaxa 2260 (1)</i> on pages 321-323, DOI: 10.11646/zootaxa.2260.1.12, http://zenodo.org/record/5320964
description: {"references": ["Lowry, J. K. &amp; Myers, A. A. (2009) Foreword. In: Lowry, J. K. &amp; Myers, A. A. (Eds), Amphipoda of the Great Barrier Reef, Australia. Zootaxa, 2260, 17 - 108.", "Hirayama, A. (1988) A ghost shrimp with four-articulate fifth pereopods (Crustacea: Caprellidea: Phtisicidae) from Northwest Australia. Zoological Science, 5, 1089 - 1093."]}