Neastacilla soelae, King, 2003

King, R. A., 2003, Neastacilla Tattersall, 1921 redefined, with eight new species from Australia (Crustacea: Isopoda: Arcturidae), Memoirs of Museum Victoria 60 (2), pp. 371-416 : 401

Neastacilla soelae sp. nov.

Figures 20–21

Material examined. Holotype. Australia: WA, between Dampier and Port Hedland, 19º59.3'S, 117º03.6'E, 52 m, 22 Feb 1983, NMV J16652 (1 female, 7 mm).

Paratypes. Australia: WA. Between Dampier and Port Hedland, type locality, NMV J16930 (1 female, 8 mm) ; 19º27.2'S, 118º58.6'E, 36–46 m, 8 Dec 1982, NMV J40681 (1 female, 9 mm) ; 19º29.7'S, 118º52.2'E, 39 m, 24 Oct 1983, NMV J40682 (1 female, 7.5 mm) ; 19º56.7'S, 117º53.8'E, 43 m, 26 Aug 1983, NMV J40683 (1 female, 8.5 mm) .

Description of female. Head with 2 dorsal elevations between eyes and smaller dorsal elevation anterior to eyes, with setae on elevations, anterolateral lobes angular, rostral point present; lateral margin of head and pereonite 1 not incised, with small flared anterolateral extension. Pereonite 2 with 1 dorsal tuberculate elevation with setae. Pereonite 3 with 2 dorsal elevations with setae. Pereonite 4 about 10 times as long as pereonite 3; with small tuberculate dorsal elevations with dorsal setae along length, anterolateral margins extended and rounded. Pereonites 5–7 with tuberculate elevations with setae. Pleon longer than combined lengths of pereonites 5–7; with small tuberculate dorsal elevations with dorsal setae, with lateral wings, long and tapering, apex acute.

Eyes small and round. Antenna 1 reaching past second peduncular article of antenna 2; aesthetascs present distally and laterally on flagellum. Antenna 2 slender, more than half as long as body; flagellum of 2 articles ending with claw, row of scales undetected.

Maxilla 1 mesial lobe with 3 terminal setae; lateral lobe with 10 distal robust setae. Maxilla 2 mesial lobe with 16 plumose setae, middle lobe with 3 setae, lateral lobe with 3 setae. Maxillipedal endite with 9 mesial setae; 1 coupling hook; palp article 2 with mesial setal rows, articles 3 and 4 with mesial and lateral setal rows, article 5 with mesial and distal setae.

Pereopod 1 propodus slightly shorter than carpus; dactylus longer than wide; without unguis. Pereopods 2–4 without dactylus. Pereopods 5–7 dactylus not denticulate, with unguis and secondary unguis; secondary unguis setiform and slender, only slightly smaller than primary unguis. Uropodal exopod with 2 setae of equal length. Oostegite 4 with a posterior suture.

7–9 mm.

Male. Unknown.

Distribution. Australia: Western Australia; subtidal to 52 m depth.

Etymology. This species is named after the research vessel from which the specimen was collected, RV Soela.

Remarks. This species is from a region (north-western Australia) where little is known about the arcturid fauna. The long tapered pleotelson, loss of dactyli on pereopods 2–4 (a state possessed by N. yuriel sp. nov.) and the setose secondary dactlyus on pereopods 5–7 (also found in N. lawadi sp. nov.) characterise this species.

Figures

Figure 20. Neastacilla soelae sp. nov., female holotype (NMV J16652): A, lateral view; B, dorsal view; C, ventral view with oostegites; A1, A2, left MXP, MX1, MX2, MD. Scale: a (A, C) = 1.0 mm; b (B) = 1.0 mm; c (A2) = 0.5 mm; d (A1) = 1.0 mm; e (MXP, MX1, MX2, MD) = 0.5 mm.

Figure 21. Neastacilla soelae sp. nov., female holotype (NMV J16652): P1, P3, P5, U. Scale: a (P1, P3) = 0.5 mm; b (U) = 0.5 mm