Pygolabis paraburdoo, 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 : 19-22

Pygolabis paraburdoo sp. nov. ( Figs 10–11 )

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

Type material. Western Australia: Pilbara Region, Parburdoo Town Bore Field: Holotype male, body length 12.9 mm, bore PTO3­A, 23°11.28'S 117°40.64'E, fld. no. PSS 111, 22 xi 2003 (M.D. Scanlon, J.S. Cocking), depth to water 6 m, depth to bottom 51 m ( WAM C34951, slide STY 005). Paratypes: male, body length 8.0 mm, pereopods and pleopods dissected for examination and illustration or SEM, ground water monitoring bore near Paraburdoo , 23°11.16'S 117°41.31'E, fld. no. HI­148 16 vii 2000 (S. Anstee) (AM P70416); 2 males, female, near Paraburdoo , 23°11.2'S 117°41.3'E, fld. no. HI­649 (S. Anstee) (AM P70417); 1 male, 1 female ( WAM C34952), 1 male, 1 female (AM P70418), bore PTO3­A Ashburton River catchment, 23°11.29'S 117°40.64'E, fld. no. PSS 111, 9 iv 2003 (S.A. Halse, A.E MacIntosh); male, bore PFO9­4 Turee Creek Bore Field Ashburton River catchment, 23°22.11'S 117°57.59'E, fld. no. PSS 058 8 iv 2003 (M.D Scanlon, S.A Halse) (AM P70419); male, body length 9.1 mm, bore PSPRSLK20 Rocklea Station Ashburton River catchment, 23°01.53'S 117°32.41'E, fld. no. PSS 177, 26 vii 2003 (M.D Scanlon, J.S. Cocking) (AM P70420).

Diagnosis. Pleotelson. Distance between uropod insertions and apex subequal to half length of pleotelson; lateral inflection points of posterior margin closer to apex than to uropod insertions; 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 subequal to lateral teeth in middle of ridge; lateral margin not distinctly projecting — forming smoothly rounded arc; distal tip with broad cup; medial distal margin rounded. Uropods. Protopod extending subequal to pleotelson apex or extending beyond pleotelson apex.

Description. Head. Length 0.63–0.76 width (holotype), 1.43–1.52 pereonite 1 medial length (holotype); clypeus proximal width 0.66 head width.

Pereonites. Total medial length 0.43–0.47 body length (holotype); medially 3–4 subequal and longest, 2 and 5–7 subequal.

Pleonites. 1–4 subequal to each other and pereonite 1, pleonite 5 length subequal to pereonites 2 and 5–7; respective medial lengths: body length — 0.05, 0.05, 0.05, 0.05, 0.07.

Pleotelson. Medial length 1.14–1.37 width (holotype), 0.49–0.5 pleon length (holotype 0.49); distance between uropod insertions and apex 0.48 total medial length of pleotelson; lateral inflection points of posterior margin occurring at 0.52 of distance between the uropod insertions and apex; distance from lateral inflection points of posterior margin to apex 0.94 distance from uropod insertions to lateral inflection points of posterior margin; posterolateral margins with 20 small non­sensillate simple setae (approximately).

Antennula . Length 0.22–0.26 body length (holotype 0.22); with 18–22 articles (differs from side to side 18–20 in paratype, holotype 22); article 2 subequal to article 1, article 3 shorter than article 1.

Antenna. 0.43–0.53 body length (holotype 0.43); with 38–41 articles (holotype). Flagellum length 0.64–0.67 antenna total length (holotype 0.64).

Pereopods. Pereopods 1–7 respective lengths: body length — 0.16, 0.29, 0.26, 0.19, 0.23, 0.26, 0.28. Pereopod 1 propodus, carpus and merus with robust bidenticulate sensillate setae, respectively 6, 1–4 (1 strongly and 3 weakly bidenticulate). Pereopods 2– 3 carpus with 18, 19 robust sensillate setae respectively, lateral row with 12 robust setae.

Pleopods. Pleopod 2 male endopod appendix masculina length 0.96 distance from base of appendix masculina to distal margin of exopod; lateral margin with 20–21 (holotype) teeth, including 3–5 distal elongate spine­like teeth (holotype 4); distal segment length 1.02–1.29 width (holotype 1.02).

Uropods. Length 0.1–0.14 body length (holotype 0.10), 0.33–0.5 pleon length (holotype 0.33). Protopod length between insertion and distal margin 1.01–1.17 length between insertion and pleotelson apex (holotype 1.01); with 12 small tooth­like setae along medial margin. Endopod length 0.57–0.76 protopod length (holotype), 1.31–1.4 exopod length (holotype); medial margin without penicillate setae, without small toothlike setae. Exopod length 0.43–0.54 protopod length (holotype).

Remarks. Pygolabis paraburdoo is most similar to P. humphreysi and P. gascoyne . It differs from P. humphreysi in having a truncate indented pleotelson apex (compared to rounded and entire) and an appendix masculina with teeth on the distal lateral margin distinctly separated for more than half of the distance in which they occur (compared to not distinctly separated). Pygolabis paraburdoo differs from P. gascoyne in having the appendix masculina with teeth on the distal lateral margin distinctly separated for more than half of the distance in which they occur (compared to not distinctly separated) and the medial distal margin rounded (compared to angular).

Distribution. Paraburdoo Town Borefield 23°01.53–22.11'S 117°32.41–57.59'E, Pilbara Region, Western Australia.

Figures

FIGURE 10. P. paraburdoo sp. nov. Holotype male, (WAM C 34951). Bold arrow showing indentation on tip of pleotelson. Scale bar 1 mm.

FIGURE 11. P. paraburdoo sp. nov. Paratype male 2 (AM P 70416); holotype male (WAM C 34951). Scale bar 0.5 mm.