Panathura hamelini, Poore, Gary C. B., Lew, Helen M. & Ton, 2002

Poore, Gary C. B., Lew, Helen M. & Ton, 2002, Expanathuridae (Crustacea: Isopoda) from the Australian region, Zootaxa 82, pp. 1-60 : 43-46

Panathura hamelini n. sp. ( Figs 26 & 27 )

Material examined.– Holotype. Australia. Tasmania, Spiky Bridge Coastal Reserve, 8 km S of Swansea reef in small bay below Spiky Bridge (42°08'S, 148°08'E), 2 m, Caulerpa and trapped sand, G.C.B. Poore and H.M. Lew Ton, 21 Mar 1988 (stn TAS 75), NMV J17202 (ovigerous female, 3.8 mm, 2 slides).

Description: Ovigerous female. Head little longer than wide, with obscure broad rostrum, with 3 pairs of lateral setules; eyes dorsal. Pereonites of equal width, 3 the longest and 7 0.7 length of pereonite 6. Pleonites 1–4 of approximately equal length, 5 twice as long, 6 longer, 1–5 about as long as pereonite 6, pleotelson longer than pereonites 6–7; pleonite 4 with c. 10 marginal plumose setae laterally on epimeron, pleonite 5 with c. 20 marginal plumose setae laterally. Telson base 0.7 width of widest point, halfway along, dorsally concave, apex evenly rounded; telson and inner surfaces of uropodal rami with scattered setules and telson apex with medial pair of short setae and, on each side, 4 longer setae.

Head, pereon and pleonites 1–6 with scattered dorsal brown pigment patches.

Antenna 1 peduncle with stout article 1, narrower articles 2 and 3; flagellum shorter than last peduncle article, of short article 1 with pappose seta, article 2 narrow and with 2 aesthetascs. Antenna 2 peduncle longer than antenna 1, article 2 not produced, articles 3 and 4 short, 5 longer than wide; flagellum of 1 long article and 4 smaller articles.

Mouthparts as in P. baudini .

Pereopod 1 subchelate, with proximal articles stout as in pereopods 2 and 3, stronger than in more posterior limbs; carpus triangular, with 3 setae on posterior margin; propodus 1.7 times as long as wide, palm axial, irregular, with 3 setae, mesial face with 3 setae, 1 stronger; dactylus weakly closing on palm, unguis almost half its length. Pereopod 2 merus cupping triangular carpus; carpus not reaching anterior margin, with weakly setose posterior margin; propodus weakly swollen, palm irregularly toothed, with distal spiniform seta, few palmar fine setae. Pereopod 3 similar to pereopod 2. Pereopods 4–6 similar; carpus short and trapeziform; carpus with 2 short spiniform setae on posterior margin; propodus with 1 distal short spiniform seta and few finer setae; dactylus weakly curved, unguis one­third length. Pereopod 7 carpus and propodus longer than in more anterior pereopods; propodus with 2 spiniform setae on posterior margin, plus 2 anterodistal double­pectinate setae.

Oostegites on pereopods 2–5.

Pleopods similar to P. baudini . Uropodal endopod longer than peduncle, reaching near to end of telson; endopod 1.3 times as long as wide, distally and laterally setose; exopods overlapping in midline, 1.7 times as long as wide, with negligible marginal excavation, posteriorly almost truncate, 16 marginal setae well spaced.

Juvenile and male. Unknown.

Size: Unique ovigerous female, 3.8 mm.

Distribution: Tasmania; algal community, 2 m depth.

Etymology: For Emmanuel Hamelin, Captain of Le Naturaliste, one of two French ships that spent 1801–1804 exploring in southern Australian waters.

Remarks: Panathura hamelini n. sp. is distinguished from the other more common coloured species from southern Australia, P. hicksi n. sp., by the more oval shape of the telson.

Figures

FIGURE 26. Panathura hamelini n. sp. Holotype, NMV J 17202. Scale bar = 1 mm.

FIGURE 27. Panathura hamelini n. sp. Holotype, NMV J 17202.