Pseudione chiesai, Pereira & Doti & Roccatagliata, 2021

Pereira, Emanuel, Doti, Brenda Lía & Roccatagliata, Daniel, 2021, A new species of Pseudione sensu lato (Isopoda: Bopyridae) on a squat lobster host from the deep South-West Atlantic, Zootaxa 4996 (2), pp. 363-373 : 365

Pseudione chiesai n. sp.

( Figs 2–5 )

Material examined. RV Puerto Deseado, Survey “Talud Continental I”, Sta. 31, 38°01.49’S, 54°44.17’W, 819 m, bottom otter trawl, 16 Aug. 2012, coll. I.L. Chiesa, 1 brooding female with eggs plus 1 cryptoniscus larva, 12,2 mm, Holotype (MACN-In 43752), 1 adult male, 4.2 mm, Allotype (MACN-In 43753), both infesting the right branchial chamber of a female Munida spinosa Henderson, 1885 , CL 29.5 mm (MACN-In 43754) .

Diagnosis. Brooding female: dextral, broadest at pereomere 3. Head separated from pereomere 1. Frontal lamina 0.1 times head length, with few shallow indentations; barbula with 2 pairs of lateral projections, outer pair larger than inner pair. Maxilliped palp 1-segmented, setose. Coxal plates 1–4 well developed, visible on both sides. Coxal plates and tergal projections with irregular margins (more prominent on right than left side). Pereomeres 5–7 with single/branched lateral digitations. Oostegite I, posterior segment “arched”. Pereopods I–VII bases each with round- ed dorsal bulge. Pleon of 5 segments plus pleotelson; lateral plates distally rounded and directed laterally. Five pairs of biramous pleopods. Uropods uniramous. Adult male: head separated from pereomere 1, pleon with 5 segments (pleomere 4 partially fused to pleomere 5 + pleotelson), pleopods oval, flattened (not tuberculiform).

Figures

FIGURE 2. Munida spinosa Henderson, 1885 (MACN-In 43754).A, female with right branchial chamber deformed. Pseudione chiesai n. sp., B–C, female holotype (MACN-In 43752). B, dorsal view; C, ventral view (some of the eggs exhibiting staining by Chlorazol Black E®). D–E, male allotype (MACN-In 43753). D, dorsal view; E, ventral view. Scale bars: A = 25 mm; B, C = 5 mm; D, E = 2 mm.

FIGURE 3. Pseudione chiesai n. sp. female holotype (MACN-In 43752).A, habitus in dorsal view; B, head and pereomere 1 in horizontal plane; C, barbula; D, left maxilliped in external view, with detail of palp.Abbreviations: cp, coxal plate; cs, cuticular slit; ur, uropod. Pleopods are identified with Roman numbers. Scale bars: A = 5 mm; B–D = 1 mm.

FIGURE 4. Pseudione chiesai n. sp. female holotype (MACN-In 43752). A, left oostegite I in external view; B, left oostegite I in internal view, with detail of internal ridge; C, left pereopod I in lateral view, with detail of distal end of carpus; D, left pereopod VII in lateral view, with detail of distal end of carpus. Scale bars: A, B = 1 mm; C, D = 0.2 mm.

FIGURE 5. Pseudione chiesai n. sp. male allotype (MACN-In 43753). A, habitus in dorsal view; B, pereomere 7 and pleon in ventral view; C, left pereopod I in lateral view; D, left pereopod VII in lateral view. Pleomeres were identified with Arabic numbers, and pleopods with Roman numbers. Abbreviations: cs, cuticular slit; plt, pleotelson. Scale bars: A, B = 1 mm; C, D = 0.2 mm.