Stylomesus weddellensis Brandt & Andres, 2008, sp. nov.

• Main Authors: Brandt, Angelika, Andres, Hans Georg
• Format: Other/Unknown Material
• Language: unknown
• Published: Zenodo 2008
• Subjects: Biodiversity; Taxonomy; Animalia; Arthropoda; Malacostraca; Isopoda; Ischnomesidae; Stylomesus; Stylomesus weddellensis; Weddell Sea
• Online Access: https://doi.org/10.5281/zenodo.5695399; http://treatment.plazi.org/id/03DF87B3FFB6FFF309FEFD6AFC4BFE95

Stylomesus weddellensis sp. nov. (Figs 1–7) Material examined Holotype : subadult ♂ (8.2 mm), ZMH K­ 41523, Weddell Sea; Station 81­8­E, (70° 31.08 S­ 70° 32.23 S ­ 14° 34.82 W­ 14° 34.90 W); depth 4382 m; 24 February 2005, RV Polarstern . Allotype : non­ovigerous Ψ (8.5 mm), ZMH K­ 41524, Weddell Sea; Station 81­8­E, (70° 31.08 S­ 70° 32.23 S ­ 14° 34.82 W­ 14° 34.90 W); depth 4382 m; 24 February 2005, RV Polarstern . Paratypes : 1 subadult ♂ (described and illustrated), ZMH K­41525 (slides), Weddell Sea; station 80­9­E, (70° 38.45 S­ 70° 39.18 S –14° 42.86 W­ 14° 43.43 W); depth 3100 m, 23 February 2005, RV Polarstern 1 nonovigerous Ψ, ZMH K­41526 (slides), Weddell Sea; station 81­8­E, (70° 31.08 S­ 70° 32.23 S ­ 14° 34.82 W­ 14° 34.90 W); depth 4382 m; 24 February 2005, RV Polarstern . Additional material examined : 7Ψ, 3 Mancas, Weddell Sea; station 80­9­E, (70° 38.45 S­ 70° 39.18 S – 14° 42.86 W­ 14° 43.43 W); depth 3100 m, 23 February 2005, RV Polarstern. 1 ♂, 1Ψ, 7 Mancas, Weddell Sea; station 81­8­E, (70° 31.08 S­ 70° 32.23 S ­ 14° 34.82 W­ 14° 34.90 W); depth 4382 m; 24 February 2005, RV Polarstern . Etymology The name refers to the Weddell Sea. Diagnosis Stylomesus without any spines on head, but with mediolateral to caudolateral blunt spines on pereonites 1 –3; antenna 1 consisting of 5 articles, article 2 with 4 sensory setae of varying lengths; pereopod 7 present; pereonite 7 not fused to pleotelson. Description Description of subadult holo­ and paratype males (Figs 1–5): Body 3.9 times longer than wide (Fig. 1 A). Head trapezoidal, 4 times as broad as long, anterolateral margins with strong frontolaterally acute projections; lateral margins of pereonites 2 and 3 rounded; pereonites 1–3 with 2 dorsomedial blunt short spines; pereonite 4 about as long as wide, narrowing at half length, broadest part 1.7 times as broad as narrowest part; pereonite 5 about 3.2 times as long as wide, 0.4 times as long as body, distally broadening, broadest part about twice as broad as narrowest part; pereonites 5–7 ...