Pachychelium fucaensis, Lowry & Stoddart, 2012

Lowry, J. K. & Stoddart, H. E., 2012, The Pachynidae fam. nov. (Crustacea: Amphipoda: Lysianassoidea) 3246, Zootaxa 3246 (1), pp. 1-69: 32-34

publication ID

http://doi.org/ 10.11646/zootaxa.3246.1.1

DOI

http://doi.org/10.5281/zenodo.5251240

persistent identifier

http://treatment.plazi.org/id/456087D3-363A-FFA8-B8DF-0F79FEAB4CBC

treatment provided by

Felipe

scientific name

Pachychelium fucaensis
status

sp. nov.

Pachychelium fucaensis   sp. nov.

( Figs 21 View FIGURE 21 , 22 View FIGURE 22 )

Type material. HOLOTYPE, sex not known, 2.7 mm, NMCC 1988-0047 View Materials , 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 GoogleMaps   . PARATYPES: 1 specimen, LACM 77 View Materials - 283.2 View Materials , 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 Thomas G. Thompson, stn 80835 BF.5 GoogleMaps   ; 1 specimen, LACM 77 View Materials - 284.1 View Materials , 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 Thomas G. Thompson, stn 80929 BF.1 GoogleMaps   .

Type locality. Clover Point , Juan de Fuca Strait, Vancouver Island, British Columbia, Canada, 48°23'01"N 123°21'46"W, 85 m depth GoogleMaps   .

Etymology. Named for the type locality, Juan de Fuca Strait.

Diagnostic description. Head lateral cephalic lobe large, narrowly rounded; ventral margin curved. Antenna 1 peduncular article 1 without posterodistal spine; accessory flagellum 2-articulate, article 1 long; flagellum with weak 1-field callynophore in specimen of unknown sex. Mandible 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. Maxilla 1 outer plate with 4 setal-teeth in 4/0 or 3/1 arrangement, setal-teeth smooth; palp absent. Maxilliped inner plate absent; outer plate medium size; palp 3-articulate (article 4 absent), article 3 length 2.2 × breadth. Gnathopod 1 subchelate; ischium smaller than propodus, not swollen posteroproximally; carpus extremely compressed; propodus length about 1.8 × breadth, posterior margin extremely reduced, with produced posterodistal corner, with simple robust seta; dactylus over-reaching palm. Gnathopod 2 palm minute, obtuse. Pereonite 4 without dorsal spines. Pereonite 5 without dorsal spines. Pereopod 5 merus without posteroproximal shoulder. Pereopod 6 basis with posteroventral lobe weakly produced; merus longer than broad, without posteroproximal shoulder. Pereopod 7 basis subrectangular with posterior margin smooth; merus length of anterior margin 1.7 × proximal breadth. Epimeron 3 posterior margin without projections, posteroventral corner broadly rounded. Uropod 3 biramous, inner ramus extending more than halfway along outer ramus but not reaching base of article 2. Telson   as long as broad, entire.

Remarks. Pachychelium fucaensis   and P. davidis   both have four setal-teeth in either a 4/0 or 3/1 arrangement. However, P. fucaensis   has the dactylus of gnathopod 1 over-reaching the palm (just reaching corner of palm in P. davidis   ). Pachychelium fucaensis   is the only species with a produced corner on the palm of gnathopod 1.

Distribution. Vancouver Island, British Columbia and southern California, eastern North Pacific Ocean; 85– 222 m depth.

RV

Collection of Leptospira Strains