Pygolabis weeliwolli, Keable, Stephen J. & Wilson, George D. F., 2006

Keable, Stephen J. & Wilson, George D. F., 2006, New species of Pygolabis Wilson, 2003 (Isopoda, Tainisopidae, Crustacea) from Western Australia, Zootaxa 1116, pp. 1-27 : 15-19

publication ID	https://doi.org/ 10.5281/zenodo.171623
DOI	https://doi.org/10.5281/zenodo.6494034
persistent identifier	https://treatment.plazi.org/id/02358794-FFA6-FF82-C13B-B58AFB0CFD1D
treatment provided by	Plazi
scientific name	Pygolabis weeliwolli
status	sp. nov.

Treatment

Pygolabis weeliwolli View in CoL sp. nov. ( Figs 8–9 View FIGURE 8. P View FIGURE 9. P )

Etymology. The name of this species is drawn from its type locality, and is treated as a masculine noun in apposition.

Type material. Western Australia: Pilbara region, Weeli Wolli area: Holotype male "specimen 5", body length 9.28 mm, Bore BH32s, 22°55'S 119°11'E, fld. no. BES 5489, 16 xi 1998 (S.M. Eberhard) ( WAM C34948 [specimen 5]). Paratypes: 3 males, female, same data as holotype ( WAM C34949); 2 males, female, same data as holotype except fld. no. BES 6446, 16 xi 1998 (S. Eberhard) ( WAM C34950); male, body length 8.3 mm, pereopods pleopods dissected for examination and illustration or SEM, spring, 22°55'S 119°11'E, fld. no. BES 3589 Bou–Roche pump, 16 xi 1998 (S.M. Eberhard) (AM P70413); 4 males, bore BH17S, 22°55.12'S 119°12.03'E, depth to water 3 m depth to bottom 11 m, fld. no. PSS 007, 5 x 2002 (M.D. Scanlon, J.S. Cocking) (AM P70414, slide STY003).

Other material. 4 males, 3 females, bore WB3, Road to Area C, Fortescue River catchment, 23°0.15'S 119°07.93'E, fld. no. PSS 152, 17 xi 2003 (M.D. Scanlon, J.S. Cocking) (AM P70415).

Diagnosis. Pleotelson. Distance between uropod insertions and apex less than half length of pleotelson; lateral inflection points of posterior margin midway between uropod insertions and apex; distance from lateral inflection points of posterior margin to apex less than from uropod insertions to inflection points; apex truncate, posterior margin indentation present. Pleopod 2 male endopod appendix masculina. Teeth on lateral margin separated by at least tooth width for more than half of lateral margin length, proximal teeth distinctly longer than lateral teeth in middle of ridge; lateral margin not distinctly projecting — forming smoothly rounded arc; distal tip with narrow cup; medial distal margin angular. Uropods. Protopod extending beyond pleotelson apex.

Description. Head. Length 0.71–0.8 width (holotype 0.71), 1.14–1.29 pereonite 1 medial length (holotype); clypeus proximal width 0.5 head width.

Pereonites. Total medial length 0.46–0.5 body length (holotype); medially 2–7 subequal.

Pleonites. 1–4 lengths subequal and shorter than pereonites 1–7, pleonite 5 length subequal to pereonites 1–7; respective medial lengths: body length — 0.05, 0.05, 0.05, 0.05, 0.08.

Pleotelson. Medial length 1.11–1.14 width (holotype), 0.49–0.56 pleon length (holotype); distance between uropod insertions and apex 0.43 total medial length of pleotelson; lateral inflection points of posterior margin occurring at 0.55 of distance between the uropod insertions and apex; distance from lateral inflection points of posterior margin to apex 0.81 distance from uropod insertions to lateral inflection points of posterior margin; posterolateral margins with 14 small nonsensillate simple setae (approximately).

Antennula . Length 0.25–0.28 body length (holotype 0.25); with 20–23 articles (holotype 20); articles 1–3 subequal.

Antenna. 0.47–0.54 body length (holotype 0.50); with 32–41 articles (holotype). Flagellum length 0.66 antenna total length.

Pereopods. Pereopods 1–7 respective lengths: body length — 0.17, 0.27, 0.25, 0.21, 0.22, 0.23, 0.23. Pereopod 1 propodus, carpus and merus with robust bidenticulate sensillate setae, respectively 7, 1, 1. Pereopods 2–3 carpus with 17, 15 robust sensillate setae respectively, lateral row with 11 robust setae.

Pleopods. Pleopod 2 male endopod appendix masculina length 0.91 distance from base of appendix masculina to distal margin of exopod; lateral margin with 17–23 teeth (17 in SEM, 19 in photograph from light microscope, 23 in holotype line drawing), including 2–4 distal elongate spinelike teeth (holotype 4); distal segment length 1.35– 1.79 width (holotype line drawing 1.35, 1.58 light microscope, 1.79 SEM).

Uropods. Length 0.11–0.17 body length (holotype 0.11), 0.4–0.63 pleon length (holotype 0.40). Protopod length between insertion and distal margin 1.13–1.16 length between insertion and pleotelson apex (holotype); with 9 small toothlike setae along medial margin. Endopod length 0.71–0.73 protopod length (holotype), 1.29–1.42 exopod length (holotype); medial margin without penicillate setae, with 4 small toothlike setae (mostly placed proximally). Exopod length 0.51–0.55 protopod length (holotype 0.51).

Remarks. The short pleotelson with a truncate indented apex, combined with the appendix masculina (which has a smoothly rounded lateral margin, with widely spaced teeth that are longer in the proximal portion of the margin relative to those in the middle of the margin, and a narrow distal cup with an angular medial distal margin) are characters that diagnose this species. The specimens from one site to the south west of the immediate vicinity of the type locality (AM P70415) have a pleotelson apex with the indentation weakly developed or absent. They are, therefore, excluded from the type series, but otherwise conform to the species description.

Distribution. Weeli Wolli area 22°55.00–55.12'S 119°11.00–12.03'E, and one locality to the south west 23°0.15'S 119°07.93'E, Pilbara Region, Western Australia.