Elasmopus crenulatus Berents 1983
Creators: name: Lowry, J. K.
name: Hughes, L. E.
Publisher: name: Zenodo
Year: 2009
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Amphipoda
Maeridae
Elasmopus
Elasmopus crenulatus

description: <i>Elasmopus crenulatus</i> Berents, 1983 (Figs 3, 4) <i>Elasmopus crenulatus</i> Berents, 1983: 113, figs 10–12. — Springthorpe &amp; Lowry, 1994: 13 (catalogue). — Lowry &amp; Stoddart, 2003: 178 (catalogue). <b>Material examined.</b> Holotype, male, 3.5 mm, AM P30095 (76 LIZ B 6.18.3); paratype, female, 4.8 mm, AM P30096 (76 LIZ B 6.2); 1 unsexed, AM P70573 (QLD 1618); 2 unsexed, AM P 71604 (QLD 1621); 1 unsexed, AM P70611 (QLD 1621); 10+ unsexed, AM P 70596 (QLD 1622); 6 unsexed AM P70988 (QLD 1649); 1 unsexed, AM P71603 (QLD 1670); 10+ unsexed, AM P70851 (QLD 1689); 6 unsexed, AM P70982 (QLD 1693); 1 male, 4.4 mm, 3 slides, AM P78025 (QLD 1698); 1 male, 4.8 mm, AM P78026 (QLD 1698); 10+ unsexed, AM P70929 (QLD 1698); 1 unsexed, AM P71011 (QLD 1705); 5 unsexed, AM P 71021 (QLD 1709); 7 unsexed, AM P71045 (QLD 1711); 2 unsexed, AM P71040 (QLD 1715); 1 unsexed, AM P71087 (QLD 1716); 10+ unsexed, AM P71181 (QLD 1730); 1 unsexed, AM P71275 (QLD 1770); 10+ unsexed, AM P75712 (QLD 1963); 10+ unsexed, AM P75714 (QLD 1967); 6 unsexed, AM P75713 (QLD 2006); 1 male, NTM Cr016749 (MAGNT 20). <b>Type locality.</b> Off Chinamans Ridge, Watsons Bay, Lizard Island, Queensland, Australia (14°40'S 145°27'E). <b>Description.</b> Based on holotype male, 3.5 mm, AM P30095 (Berents, 1983). <b>Head.</b> <i>Head</i> eyes ovate; lateral cephalic lobe broad, truncated, apically rounded, anteroventral margin with notch/slit, anteroventral corner rounded. <i>Antenna 1</i> longer than antenna 2; peduncular article 1 subequal in length to article 2, with 1 robust seta on posterior margin; accessory flagellum minute, with 1 article; flagellum with 8 articles. <i>Antenna 2</i> peduncular article 4 subequal to article 5; flagellum with 6 articles. <i>Mandible</i> incisor a smooth cutting edge with 2 apicomedial cusps; accessory setal row with 4 setae; palp well developed, 3-articulate; article 1 about twice as long as broad, shorter than article 2, inner margin not produced distally; article 2 subequal to article 3; article 3 short (2.3 x as long as broad), strongly falcate, longer than article 1. <b>Pereon.</b> <i>Gnathopod 1</i> coxa anteroventral corner produced, rounded, anterior margin concave; merus without posterodistal tooth; carpus about 2 x as long as broad, subequal in length to propodus, setae in anterodistal bunches and along posterior margin; propodus palm acute, straight, entire, defined by posterodistal corner, with posterodistal robust seta. <i>Gnathopod 2</i> coxa posteroventral corner notch absent; basis slender; merus with subquadrate distoventral corner; carpus compressed, not enclosed by merus and propodus, length 0.7 x breadth; propodus expanded, with dense slender setae along posterior margin, palm acute, convex, smooth, with subtriangular distomedial shelf, with group of 3 robust setae on shelf, palmar margin without robust setae, without teeth, subpalmar surface smooth, without posteroventral corner, without posterodistal robust setae; dactylus closing along palm, without setae on anterior margin, without posteroproximal shelf, apically subacute. <i>Pereopod 4</i> coxa posteroventral lobe absent, posterior margin concave. <i>Pereopod 5</i> basis proximally expanded, tapering distally, posterior margin slightly subsigmoidal, without long slender setae, posteroventral corner narrowly rounded or subquadrate; carpus and propodus with few long, slender setae along anterior margin. <i>Pereopod 6</i> basis posterior margin straight, without long slender setae, posteroventral corner narrowly rounded; carpus and propodus without long, slender setae along anterior margin; merus and carpus broadened; propodus not expanded posterodistally. <i>Pereopod 7</i> basis posterior margin convex, castelloserrate, without long slender setae, not produced posterodistally, posteroventral corner narrowly rounded; merus and carpus broadened; propodus not expanded posterodistally. <b>Pleon.</b> <i>Pleonites 1–3</i> dorsally smooth, without setae, spines or carinae. <i>Epimeron 1</i> posteroventral corner with small acute spine. <i>Epimeron 2</i> posteroventral corner acute. <i>Epimeron 3</i> ventral margin smooth, posteroventral margin smooth, posteroventral corner with small acute spine. <i>Urosomites 1–3</i> dorsally smooth, without setae, spines or carinae. <i>Uropod 1</i> peduncle with basofacial robust seta. <i>Uropod 3</i> rami distally truncated, apical robust setae long; inner ramus slightly shorter than outer ramus; inner ramus short (length 1.7 x breadth); outer ramus short, shorter than peduncle, 1-articulate. <i>Telson</i> moderately cleft (30 to 65%), broader than long, short, lobes apically truncated, without apical conical extensions, without dorsal robust setae, each lobe with 3 long and short apical robust setae, without robust setae on inner and outer margins. <b>Female</b> (sexually dimorphic characters). Based on paratype, female, 4.8 mm, AM P30096. <i>Gnathopod 2</i> carpus long, length 2 x breadth, not enclosed by merus and propodus; propodus subrectangular, palm extremely acute without corner, smooth, without shelf, without robust setae. <b>Habitat</b>. Marine, epibenthic, living on reef rock, dead coral and encrusting algae in 4 to 7 m depth. <b>Remarks.</b> This is the first record of <i>E. crenulatus</i> since the original description by Berents (1983). It is most probably the sister species of <i>E. arrawarra</i> Hughes &amp; Lowry (2006) from the Solitary Islands. <i>Elasmopus crenulatus</i> and <i>E. arrawarra</i> have a disjunct distribution along the east coast of Australia. Both species have shortened first and second antennae, a short article 3 on the mandibular palp, a short inner ramus on uropod 3 and an almost subquadrate telson with strong apical robust setae. <i>Elasmopus crenulatus</i> can be distinguished from other species on the GBR by the basis of pereopod 7 with its strongly crenulate posterior margin, by the short inner ramus on uropod 3 and the short, almost subquadrate telson with strong, apical robust setae. <b>Distribution.</b> <i>Australia</i>. Queensland: Lizard Island (Berents 1983; current study); One Tree Island (current study). Northern Territory: Darwin (current study). <i>Indian Ocean</i>. Cocos (Keeling) Islands (Berents 1983).
description: Published as part of <i>Lowry, J. K. &amp; Hughes, L. E., 2009, Maeridae, the Elasmopus group *, pp. 643-702 in Zootaxa 2260 (1)</i> on pages 649-652, DOI: 10.11646/zootaxa.2260.1.33, http://zenodo.org/record/5361655
description: {"references": ["Berents, P. B. (1983) The Melitidae of Lizard Island and adjacent reefs, The Great Barrier Reef, Australia (Crustacea: Amphipoda). Records of the Australian Museum, 35, 101 - 143.", "Springthorpe, R. T. &amp; Lowry, J. K. (1994) Catalogue of crustacean type unsexed in the Australian Museum: Malacostraca. Technical Reports of the Australian Museum, 11, 1 - 134.", "Lowry, J. K. &amp; Stoddart, H. E. (2003) Crustacea: Malacostraca: Peracarida: Amphipoda, Cumacea, Mysidacea. Beesley, P. L. and Houston, W. W. K. Zoological Catalogue of Australia. 19.2 B, i - xii, 1 - 531. Melbourne, Australia, CSIRO Publishing.", "Hughes, L. E. &amp; Lowry, J. K. (2006) New species of Amphipoda (Crustacea: Peracarida) from the Solitary Islands, New South Wales, Australia. Zootaxa, 1222, 1 - 52."]}