Pachychelium fucaensis Lowry &amp; Stoddart 2012, sp. nov.
Creators: name: Lowry, J. K.
name: Stoddart, H. E.
Publisher: name: Zenodo
Year: 2012
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Amphipoda
Pakynidae
Pachychelium
Pachychelium fucaensis

description: <i>Pachychelium fucaensis</i> sp. nov. (Figs 21, 22) <b>Type material.</b> HOLOTYPE, sex not known, 2.7 mm, NMCC 1988-0047, Clover Point, Juan de Fuca Strait, Vancouver Island, British Columbia, Canada, 48°23'01"N 123°21'46"W, 85 m, 28 August 1976, G.W. O'Connell, stn GWO W158A. PARATYPES: 1 specimen, LACM 77 - 283.2, ridge south of Santa Rosa Island, Santa Cruz Basin, off California, U.S.A., 33°49.0'N 119°59.9'W, 103–108 m, bio-box, 1977–78, Bureau of Land Management Survey, RV <i>Thomas G. Thompson</i>, stn 80835 BF.5; 1 specimen, LACM 77 - 284.1, south of Santa Cruz Island, Santa Cruz Basin, off California, U.S.A., 33°46.2'N 119°50.9'W, 222–271 m, bio-box, 1977–78, Bureau of Land Management Survey, RV <i>Thomas G. Thompson</i>, stn 80929 BF.1. <b>Type locality.</b> Clover Point, Juan de Fuca Strait, Vancouver Island, British Columbia, Canada, 48°23'01"N 123°21'46"W, 85 m depth. <b>Etymology</b>. Named for the type locality, Juan de Fuca Strait. <b>Diagnostic description.</b> <i>Head</i> lateral cephalic lobe large, narrowly rounded; ventral margin curved. <i>Antenna 1</i> peduncular article 1 without posterodistal spine; accessory flagellum 2-articulate, article 1 long; flagellum with weak 1-field callynophore in specimen of unknown sex. <i>Mandible</i> lacinia mobilis absent; lamina dentata absent; accessory setal row absent; molar absent; palp attached distally; palp article 2 broad, as long as article 3; article 3 tapered distally. <b> <i>Maxilla 1</i> outer plate with 4 setal-teeth</b> in 4/0 or 3/1 arrangement, setal-teeth smooth; palp absent. <i>Maxilliped</i> inner plate absent; outer plate medium size; palp 3-articulate (article 4 absent), article 3 length 2.2 × breadth. <i>Gnathopod 1</i> subchelate; ischium smaller than propodus, not swollen posteroproximally; carpus extremely compressed; <b>propodus</b> length about 1.8 × breadth, posterior margin extremely reduced, <b>with produced posterodistal corner, with simple robust seta</b>; dactylus over-reaching palm. <i>Gnathopod 2</i> palm minute, obtuse. <i>Pereonite 4</i> without dorsal spines. <i>Pereonite 5</i> without dorsal spines. <i>Pereopod 5</i> merus without posteroproximal shoulder. <i>Pereopod 6</i> basis with posteroventral lobe weakly produced; merus longer than broad, without posteroproximal shoulder. <i>Pereopod 7</i> basis subrectangular with posterior margin smooth; merus length of anterior margin 1.7 × proximal breadth. <i>Epimeron 3</i> posterior margin without projections, posteroventral corner broadly rounded. <i>Uropod 3</i> biramous, inner ramus extending more than halfway along outer ramus but not reaching base of article 2. <i>Telson</i> as long as broad, entire. <b>Remarks.</b> <i>Pachychelium fucaensis</i> and <i>P. davidis</i> both have four setal-teeth in either a 4/0 or 3/1 arrangement. However, <i>P. fucaensis</i> has the dactylus of gnathopod 1 over-reaching the palm (just reaching corner of palm in <i>P. davidis</i>). <i>Pachychelium fucaensis</i> is the only species with a produced corner on the palm of gnathopod 1. <b>Distribution.</b> Vancouver Island, British Columbia and southern California, eastern North Pacific Ocean; 85– 222 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 32-34, DOI: 10.11646/zootaxa.3246.1.1, http://zenodo.org/record/5249007