Paradexamine exilis Myers, 2009, sp. nov.
Creators: name: Myers, Alan A.
Publisher: name: Zenodo
Year: 2009
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Amphipoda
Dexaminidae
Paradexamine
Paradexamine exilis

description: <i>Paradexamine exilis</i> sp. nov. (Figs 9, 10) <b>Type Material.</b> Holotype, male, 1.9 mm, AM P77996, Third Beach (14°40.20'S 145°26.548'E), water column sample at night, small bay in lee of wind, with lights and hand nets over 2 m depth, J. Lowry, A. Myers &amp; L. Hughes (QLD 1805). Paratype, male, AM P77997, same data as holotype. <b>Additional material examined.</b> 9 males, AM P77998 (QLD 1805). <b>Type Locality.</b> Third Beach, Lizard Island, Queensland, Australia (14°40.20'S 145°26.548'E). <b>Etymology.</b> From the Latin 'exilis' = slender, referring to the very slender gnathopod 2. <b>Description.</b> Based on holotype, male, 1.9 mm, P77996. <b>Head.</b> <i>Head</i> lateral lobes rounded. <i>Eye</i> huge, more than half length of head, with black central core. <i>Antenna 1</i> peduncle article 1 with posterodistal blunt process tipped with long setae. <i>Antenna 2</i> length unknown; peduncle article 4 broader proximally, finely setulose; flagellum unknown. <i>Mandible</i> palp absent; incisor process with robust setal row. <i>Maxilla 1</i> palp elongate, more than four times as long as broad. <i>Maxilliped</i> palp 4-articulate. <b>Pereon.</b> <i>Gnathopod 1</i> carpus subequal in length with propodus; propodus distinctly expanded distally. <i>Gnathopod 2</i> carpus elongate, slender, subequal in length with propodus. <i>Pereopods 3–7</i> simple or scarcely prehensile. <i>Pereopod 3</i> coxa, posterodistal corner with multiple spines; dactylus more than half length of propodus. <i>Pereopods 5–7</i> of uniform morphology. <i>Pereopod 5</i> basis weakly ovate, anterior margin with short robust setae. <i>Pereopod 6</i> basis moderately broad, subovate, posterior margin convex, weakly serrate. <i>Pereopod 7</i> coxal gill present; basis strongly expanded, almost as broad as long, posterodistal margin scalloped. <b>Pleon.</b> <i>Segments</i> with the following dorsal spine arrangement (from urosomite 1 forwards): 3.3.3.1.0. <i>Epimeron 2</i> posteroventral corner produced into a strong spine. <i>Epimeron 3</i> posterior and ventral margins smooth, with a single strong posteroventral spine. <i>Urosome</i> with urosomites 2–3 fused. <i>Urosomite 1</i> with dorsal spine and two dorsolateral spines. <i>Uropod 3</i> rami with many long fine setae. <i>Telson</i> lobes distally smooth, with distal spine, with subdistal robust seta. Female (sexually dimorphic characters). Unknown. <b>Habitat.</b> Unknown. Males collected in water column at night. <b>Remarks.</b> With its elongate and slender gnathopod 2 and posterodistal extension on antenna 1, peduncle article 1, this species resembles <i>P. micronesicus</i> Ledoyer, 1979. It differs from that species in its rounded lateral cephalic lobes (strongly acute in <i>P. micronesicus</i>), the pleonal spine formula (1.3.3.3.0 in <i>P. micronesicus</i>, 3.3.3.1.0 in <i>P. exilis</i>), the projection on antenna 1, peduncle article 1 being a blunt process (acute in <i>P. micronesicus</i>), the multilobed posterodistal corner on coxa 3 (single spine in <i>P.micronesicus</i>) and the broad basis of pereopod 7 with its scalloped posterior margin (moderately expanded and serrate in <i>P. micronesicus</i>). <b>Distribution.</b> <i>Australia</i>. Queensland: Third Beach, Lizard Island (current study).
description: Published as part of <i>Myers, Alan A., 2009, Dexaminidae *, pp. 393-424 in Zootaxa 2260 (1)</i> on pages 406-408, DOI: 10.11646/zootaxa.2260.1.20, http://zenodo.org/record/5319784
description: {"references": ["Ledoyer, M. (1979) Les gammariens de la pente externe du grand recife de Tulear (Madagascar) (Crustacea, Amphipoda). Memorie del Museo Civico di Storia Naturale, Verona, 2, 1 - 150."]}