Byrathis divae Markhaseva & Renz, 2011, sp. nov.

• Main Authors: Markhaseva, Elena L., Renz, Jasmin
• Format: Other/Unknown Material
• Language: unknown
• Published: Zenodo 2011
• Subjects: Biodiversity; Taxonomy; Animalia; Arthropoda; Maxillopoda; Calanoida; Scolecitrichidae; Byrathis; Byrathis divae; Southern Ocean
• Online Access: https://doi.org/10.5281/zenodo.6193224; http://treatment.plazi.org/id/DE292E1AFFE1FFA2ADE23075F587C729

Byrathis divae sp. nov. (Figs 1–4, 9) Holotype. Dissected adult female, body length 2.39 mm. ZMH Reg. no. K–41630. Collected on 28 July 2000 by the DIVA –I expedition above the sea bed at abyssal depths (5390 m). Paratypes, body length 2.23–2.47 mm. ZMH Reg. no. K–41631, 9 adult females, the same label data as for the holotype; ZIN –91092, 8 adult females. Collected 25 July 2000 by the DIVA –I expedition in the South Atlantic (17º06.2’S 04º41.7’E), above the sea bed at abyssal depth (5415 m). Additional material: 9 females, body length 2.10–2.30 mm, collected in the South Atlantic from the equator to about 41ºS between 05ºW–09ºE at depths from 4469 to 5395 m and 6 females, body length 2.00– 2.28 mm, found in the Southern Ocean between about 58º–65ºS and 24º–51ºW at depths from 2965 to 4748 m. Type locality. South Atlantic (16º18’S 05º27’E). Description. Female. Body length 2.10–2.47 mm. Prosome 2.8–3.3 times as long as urosome (Fig. 1 A–B). Rostrum absent (Fig. 1 C–D). Cephalosome and pedigerous somite 1 and pedigerous somites 4 and 5 separate; posterior corners as short rounded lobes in lateral view, obtuse triangular in dorsal view (Fig. 1 F–G). Urosome of 4 somites (Fig. 1 E). Caudal rami with 1 dorsal seta (later broken in studied specimens), 1 ventral seta, and 4 terminal setae. Antennule (Fig. 2 A–C) extending to distal margin of urosomal somite 3–4, of 24 articulating segments; armature as follows: I–3 s, II– IV–6 s + 1ae, V–2 s + 1ae, VI–2 s, VII–2 s + 1ae, VIII–2 s, IX–2 s + 1ae, X– XI–4 s + 1ae, XII–1 s, XIII–1s, XIV–2s + 1ae, XV–1s, XVI–2s + 1ae, XVII–1s + 1ae (or 2s), XVIII–2s, XIX–2s, XX–2s, XXI–1s + 1ae, XXII–1s, XXIII–1s, XXIV–2s, XXV–2s, XXVI–2s, XXVII–XXVIII–5s + 1ae (setation on Fig. 2 A–C is based on the holotype and supplemented considering the paratypes and additional females). Antenna (Fig. 3 A–B), coxa with 1 seta, basis with 2 setae; exopod of 7 segments with 1, 1-1-1-1, 1, 1, 1, 1, and 3 setae, seta on proximal exopod segment rudimentary, following complex segment with 3 rudimentary ...