Tethygonium monocuspis Just & Wilson 2021, sp. nov.

• Main Authors: Just, Jean, Wilson, George D. F.
• Format: Other/Unknown Material
• Language: unknown
• Published: Zenodo 2021
• Subjects: Biodiversity; Taxonomy; Animalia; Arthropoda; Malacostraca; Isopoda; Paramunnidae; Tethygonium; Tethygonium monocuspis; Seal Islands
• Online Access: https://doi.org/10.5281/zenodo.4690298; http://treatment.plazi.org/id/03C487E378016403FF09EBF2EA83FD1F

Tethygonium monocuspis sp. nov. (Figs 26–27) Type fixation . Holotype , ♀, AM P60463.—Here designated. Type locality. Victoria, south-east Australia. Etymology . The species is named for the single lateral spine on pereionite 2. Material examined. Holotype . ♀, 0.9 mm, Australia, Victoria, east of Seal Islands, 38 o 59.1’S, 148 o 31.6’E, collected with benthic sled, stn SS05/94/60, AM P60463. Paratypes . Australia, New South Wales, off Nowra, 34 o 59.52’S, 151 o 5.94’E, 204 m, coarse shell, WHOI epibenthic sled, GCB Poore et al ., CSIRO RV Franklin , 14 July 1986, stn SLOPE 1, NMV J20116, (1 late ♂ manca, pereiopod VII and pleopod I not fully developed). Australia, New South Wales, off Nowra, 34 o 59.52’S, 151 o 5.94’E, 204 m, coarse shell, WHOI epibenthic sled, Poore, GCB et al ., CSIRO RV Franklin , 14 July 1986, stn SLOPE 1, NMV J20117, (1 ♀). Description (female). Body width 0.50 length, widest at pereionite 2. Head length 0.53 width; length posterior to eyestalks 1.2 anterior length. Frontal margin convex with weak rounded mid projection, with blunt angular lateral margins adjacent to antennae. Eyestalks slightly longer than broad, reaching to about middle of pereionite 1 anterior margin, apex rounded, long axis angling forward at approximately 30°, (ocelli not observed). Pereionites 1 and 3–7 lateral margin rounded, lateral margin of pereionite 2 angular with forward projecting spine; coxae visible in dorsal view on pereionites 1 and 5–7 (1–7 in ♂). Pereionite 1 sagittal length 2.5 pereionite midline length. Pleon length 1.2 width. Pleonite 1 width equal to distance between uropods, length 0.2 width. Pleotelson laterally convex, lacking inflection between lateral and proximal margins, with 9–10 small denticles per side; posterior projection, set apart from lateral margins by concavity at level of uropods, forming 70° angle with broadly rounded setiferous apex. Antennula article 1 reaching much beyond eye lobes and pereionites1, article 2 about 0.75 length of 1, 1 and 2 of equal width, tubular; articles 5 ...