Podocerus casuarinensis Kilgallen 2009, sp. nov.
Creators: name: Kilgallen, Niamh M.
Publisher: name: Zenodo
Year: 2009
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Amphipoda
Podoceridae
Podocerus
Podocerus casuarinensis

description: <i>Podocerus casuarinensis</i> sp. nov. (Figs 3, 4, Pl. 6B) <b>Type material.</b> Holotype, female, 3 mm, AM P71219, Casuarina Beach, Lizard Island (14°40.38’S 145°26.69’E), fine sediment in grass beds, sandy bottom with rubble, algae &amp; sparse seagrass, 1 m, S. LeCroy, 2 March 2005 (QLD 1771). <b>Type locality.</b> Casuarina Beach, Lizard Island, Queensland, Australia (14°40.38’S 145°26.69’E). <b>Additional material examined.</b> 1 female, AM P76252 (QLD 1625); 1 female, AM P70576 (QLD 1627); 1 female, AM P70651 (QLD 1635). <b>Etymology.</b> Named for the type locality. <b>Description.</b> Based on holotype, female, 3 mm, AM P71219. <b>Head.</b> <i>Eyes</i> large, protruding. <i>Antenna 1</i> between 0.3–0.5 body length; accessory flagellum present, 1- articulate; primary flagellum about 40% of peduncle length, with 4–5 articles. <i>Antenna 2</i> distinctly longer than antenna 1, flagellum with 4–5 articles. <i>Mandible</i> incisor with 5 teeth; molar well developed. <i>Maxilliped</i> inner plate smaller than outer plate, quadrilateral; outer plate about twice length of inner plate, inner margin with row of robust setae, with a few fine setae; palp article 2 scarcely setose on inner margin; article 3 with few distal setae; article 4 reduced, blunt. <b>Pereon.</b> <i>Pereonites</i> not fused; pereonites 2–6 with gills; pereonites 6–7 posterodorsally produced; pereonite 7 with clump of dorsal setae. <i>Gnathopod 1</i> propodus triangular to subtriangular; palm transverse, minutely serrate, beginning less than halfway along posterior margin of propodus; dactylus fitting palm, with 1 accessory tooth. <i>Gnathopod 2</i> coxa reduced; basis with rounded anterodistal lobe; merus with short, blunt distal projection; propodus large, subovate, length about 1.5 x width; palm defined by small proximal projection with 2 robust setae, minutely serrate, without distal shelf sinus or midpalmar projection. <i>Pereopods 3–4</i> well developed; basis narrow, cylindrical. <i>Pereopod 5</i> basis subrectangular, slightly longer than merus; carpus distinctly longer than merus; propodus slightly shorter than carpus and merus combined; dactylus longer than half propodus length. <i>Pereopod 6</i> basis and carpus subequal in length, shorter than merus; propodus subequal in length to carpus and merus combined; dactylus longer than half propodus length. <i>Pereopod 7</i> similar to pereopod 6; propodus shorter than carpus and merus combined. <b>Pleon.</b> <i>Pleonites</i> not fused; pleonites 1 and 2 posterodorsally produced; pleonite 1 with clump of dorsal setae. <i>Uropods 1</i> and <i>2</i> well developed; peduncle without distoventral spine; biramous with inner ramus distinctly longer than peduncle, lacking marginal row of robust setae, but with row of fine denticles on inner margins. <i>Uropod 3</i> uni-articulate. <i>Telson</i> apically rounded, posterodorsally produced into subacute knob with 2 apical setae. <b>Habitat.</b> In sea grass beds on fine sediment, and on rubble algae and seagrass over sandy substrate, 1–2.5 m. <b>Male</b> (sexually dimorphic characters). Males not known. <b>Remarks.</b> The present species differs from the female of <i>Podocerus crenulatus</i> Myers, 1985, by the 1- articulate accessory flagellum; the shape of articles 4 and 5 of the second antenna; the more transverse nature of the gnathopod 1 palm; the lack of dorsolateral lobes on pereonite 7 and pleonites 1–2; and the apically rounded telson. <i>Podocerus crenulatus</i> females, conversely, have a 2-articulate accessory flagellum, a distomedial inflated article 4 and a curved article 5 of antenna 2, an oblique gnathopod 1 palm, distinct dorsolateral lobes on pereonite 7 and pleonites 1–2, and a subtriangular telson. <i>Podocerus casuarinensis</i> differs from the female of <i>P. sandroruffoi</i> Ortiz &amp; Lalana, 2003, by the serrated gnathopod 1 palm margin; the lack of serrations on the inner margin of the gnathopod 1 dactylus; the more ovate gnathopod 2 propodus; the relative lengths of the uropods 1–2 rami; and the shape of the telson. In <i>P. sandroruffoi</i> the gnathopod 1 palm is not serrated, but the inner margin of the dactylus of the same appendage is serrated, the gnathopod 2 propodus of the female is more subtriangular in shape, the inner rami of uropods 1 and 2 are shorter than their respective peduncles, and the telson is subquadrate in shape. <i>Podocerus inconspicuus</i> (Stebbing, 1888) is also morphological similar, but lacks the dorsal carination of this species, and the gnathopod 1 palm begins more than halfway along the posterior margin of the gnathopod 1 propodus, whereas it begins about one-third of the way along the posterior margin in <i>P. casuarinensis</i>. <b>Distribution.</b> <i>Australia</i>. Queensland: Lizard Island (current study).
description: Published as part of <i>Kilgallen, Niamh M., 2009, Podoceridae *, pp. 841-860 in Zootaxa 2260 (1)</i> on pages 844-845, DOI: 10.11646/zootaxa.2260.1.47, http://zenodo.org/record/5306797
description: {"references": ["Myers, A. A. (1985) Shallow water, coral reef and mangrove Amphipoda (Gammaridea) of Fiji. Records of the Australian Museum, Supplement, 5, 1 - 143.", "Ortiz, M. &amp; Lalana, R. (2003) On a new species of Podocerus (Amphipoda: Gammaridea: Podoceridae) from the Indonesian Archipelago. Travaux du Museum National d'Histoire Naturelle \" Grigore Antipa \", 45, 61 - 66.", "Stebbing, T. R. R. (1888) Report on the Amphipoda collected by H. M. S. Challenger during the years 1873 - 1876. Report on the Scientific Results of the Voyage of H. M. S. Challenger during the years 1873 - 76, Zoology, 29, 1 - 1737, pls 1731 - 1210."]}