Pachynus denticulatum Lowry 1984
Creators: name: Lowry, J. K.
name: Stoddart, H. E.
Publisher: name: Zenodo
Year: 2012
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Amphipoda
Pakynidae
Pachynus
Pachynus denticulatum

description: <i>Pachynus denticulatum</i> Lowry, 1984 (Figs 27, 28a, b) <i>Pachynus denticulatum</i> Lowry, 1984: 84, figs 25–27. &amp;horbar; Barnard &amp; Karaman, 1991: 510. &amp;horbar; Springthorpe &amp; Lowry, 1994: 14. <i>Pachynus denticulatus</i>. &amp;horbar; Lowry &amp; Stoddart, 2003: 169. <b>Material examined.</b> One ovigerous female, 2.8 mm, AM P.46676, Horseshoe Reef, outer Barrier Reef, off Bootless Bay, Papua New Guinea, approx. 9°36'S 147°17'E, 30 m, steep sand and shell slope at base of front face, 28 October 1980, S. Arnam, stn PNG-19. – 1 male, AM P.46677, same locality, sand, 44 m, 9 November 1980, J.K. Lowry &amp; S. Arnam, stn PNG-60. – 1 specimen, AM P.46613, off Cape Banks, New South Wales, Australia, 34°S 151°16'E, 25–30 m, sand, November 1990, The Ecology Lab. – 2 specimens, AM P.46614, same data, 45–50 m. – 3 specimens, AM P.46616, south-east of Bate Bay, New South Wales, Australia, 34°05.9'S 151°12'E, 45–50 m, sand, 24 January 1990, The Ecology Lab, stn Cobblers T1 S2 R2. – 1 specimen, AM P.46615, same data, July 1990, stn Cobblers S 2 R2. – 1 specimen, AM P.46618, south-east of Bate Bay, New South Wales, Australia, 34°06.8'S 151°10'E, 45–50 m, sand, July 1990, The Ecology Lab, stn T2 S3 R2. – 1 specimen, AM P.46617, same data, January 1991, stn T4-331. – 41 specimens in 9 lots, AM P.46602 to P46610, off Bass Point, New South Wales, Australia, 34°36'S 150°54'E, 35–70 m, sand, November 1990 to January 1991, The Ecology Lab. – 6 specimens, AM P.46397, off Wattamolla, New South Wales, Australia, 34°44'S 150° 39'E, 45–50 m, sand, January 1990, The Ecology Lab, stn S1 R3. – 3 specimens, AM P.46612, same data, stn S3. – 1 specimen, AM P.46557, same data, 35–40 m, stn S2 R2. – 6 specimens, AM P.46611, same data, stn S3. – 1 specimen, AM P.46675, off Providential Head, New South Wales, Australia, 34°44'S 150° 39'E, 25–30 m, baited trap set overnight, 15 January 1991, S.J. Keable, A. Parker &amp; J.K. Lowry, MV <i>Krista</i>, stn PIO-109. – 3 specimens (including ovigerous female), AM P.68501, east of Lakes Entrance, Victoria, Australia, 37°55.6’S 148°15.1’E, 41 m, benthic sled, 25 August 1994, P.B. Berents, FRV <i>Southern Surveyor</i>, stn 05/94/41. – 7 specimens, MV J22338, 10.5 km east-south-east of eastern edge of Lake Tyers, Victoria, Australia, 37°54.07'S 148°12.09'E, 42 m, sand and shell, Smith-McIntyre grab, 25 September 1990, Marine Science Laboratories, stn MSL-EG 32. – 2 specimens, MV J22339, 8.6 km west-south-west of Cape Conran, Victoria, Australia, 37°51.19'S 148°38.53'E, 51 m, mud and shell, Smith-McIntyre grab, 28 September 1990, Marine Science Laboratories, stn MSL-EG 56. – 1 specimen, MV J62410, 85 km north-east of North Point, Flinders Island, eastern Bass Strait, Australia, 39°02.4'S 148°30.6'E, 120 m, muddy sand, 15 November 1981, R. Wilson, RV <i>Tangaroa</i>, stn BSS 169. – 1 specimen, MV J2501, 42 km south-west of Babel Island, Tasmania, eastern Bass Strait, Australia, 40°14.4'S 148°40.0'E, 60 m, muddy sand, Smith-McIntyre grab, 14 November 1981, R. Wilson, RV <i>Tangaroa</i>, stn BSS-165G. – 4 specimens, MV J62422, 5 km north of North Point, Tasmania, central Bass Strait, Australia, 40°40.3'S 145°15'E, 33 m, medium shell, epibenthic sled, 4 November 1980, M. Gomon &amp; G.C.B. Poore, FRV <i>Sarda</i>, stn BSS 115S. – 1 specimen, MV J62412, same data, Smith-McIntyre grab, stn BSS 115G. <b>Diagnostic description.</b> <i>Head</i> lateral cephalic lobe small, subacute; ventral margin curved. <i>Antenna 1</i> peduncular article 1 without posterodistal spine; <b>accessory flagellum absent</b>; flagellum with weak 1-field callynophore in female, strong 1-field callynophore in male. <i>Mandible</i> lacinia mobilis a simple robust seta; lamina dentata absent; accessory setal row present, not on raised setose ridge; <b>molar absent</b>; palp attached midway; palp article 2 slender, longer than article 3; article 3 with subparallel margins. <b> <i>Maxilla 1</i> outer plate with 8 setal-teeth</b> in 5/3 arrangement, setal-teeth smooth; palp well developed, 2-articulate, with apical robust setae. <i>Maxilliped</i> inner plate small; outer plate small; palp 4-articulate, article 4 large. <i>Gnathopod 1</i> chelate; ischium smaller than propodus, not swollen posteroproximally; carpus extremely compressed; propodus length about 1.6 × breadth, posterior margin well developed, with produced corner, corner of palm with complex robust seta; dactylus reaching to corner of palm. <i>Gnathopod 2</i> propodus, length more than 2 × breadth, palm minute, transverse. <i>Pereonite 4</i> without dorsal spines. <i>Pereonite 5</i> without dorsal spines. <i>Pereopod 5</i> merus with posteroproximal shoulder. <i>Pereopod 6</i> basis with posteroventral lobe produced beyond ischium; merus broader than long, with posteroproximal shoulder. <i>Pereopod 7</i> basis subquadrate, about 1.5 × as long as wide with posterior margin weakly dentate. <i>Epimeron 3</i> posterior margin without projections, posteroventral corner acutely produced. <i>Uropod 3</i> biramous, inner ramus just reaching base of article 2 of outer ramus. <i>Telson</i> longer than broad, entire. <b>Remarks.</b> <i>Pachynus denticulatum</i> and <i>P. pugilator</i> both have the epimeron 3 posteroventral corner acutely produced. They differ in the accessory flagellum (present in <i>P. pugilator</i>, absent in <i>P. denticulatum</i>); in mandibular palp article 2 (subequal to article 3 in <i>P. pugilator</i>, longer in <i>P. denticulatum</i>); and in the shape of the pereopod 5 basis (subovate in <i>P. pugilator</i>, subquadrate in <i>P. denticulatum</i>). The shape of the epimeron 3 posteroventral corner varies slightly, as shown in fig. 28. <b>Distribution.</b> Southern Papua New Guinea and south-eastern Australia, western South Pacific Ocean; 25–120 m depth.
description: Published as part of <i>Lowry, J. K. &amp; Stoddart, H. E., 2012, The Pachynidae fam. nov. (Crustacea: Amphipoda: Lysianassoidea) 3246, pp. 1-69 in Zootaxa 3246 (1)</i> on pages 40-42, DOI: 10.11646/zootaxa.3246.1.1, http://zenodo.org/record/5249007
description: {"references": ["Lowry, J. K. (1984) Systematics of the pachynid group of lysianassoid Amphipoda (Crustacea). Records of the Australian Museum, 36 (2), 51 - 105.", "Barnard, J. L. &amp; Karaman, G. S. (1991) The families and genera of marine gammaridean Amphipoda (except marine gammaroids). Records of the Australian Museum, Supplement, 13 (2), 419 - 866.", "Springthorpe, R. T. &amp; Lowry, J. K. (1994) Catalogue of crustacean type specimens 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. In P. L. Beesley &amp; W. W. K. Houston (eds), Zoological Catalogue of Australia, Vol. 19.2 B, 531 pp, Melbourne: CSIRO Publishing, Australia."]}