Orbiniella mayhemi Meca & Kongsrud & Kongshavn & Alvestad & Meißner & Budaeva 2024, sp. nov.

• Main Authors: Meca, Miguel A., Kongsrud, Jon Anders, Kongshavn, Katrine, Alvestad, Tom, Meißner, Karin, Budaeva, Nataliya
• Format: Other/Unknown Material
• Language: unknown
• Published: Zenodo 2024
• Subjects: Biodiversity; Taxonomy; Animalia; Annelida; Polychaeta; Orbiniida; Orbiniidae; Orbiniella; Orbiniella mayhemi; Arctic; Iceland
• Online Access: https://doi.org/10.5281/zenodo.12190926; http://treatment.plazi.org/id/6BE73540FD8B531E838242CEB978411A

Orbiniella mayhemi Meca & Budaeva, sp. nov. Figs 6, 7 Clade. Deep 3. Type material examined. Holotype SMF 32627 (DNA voucher Orbi 19). Paratypes SMF 32588 (1 paratype); SMF 32628 (1 paratype on SEM stub); SMF 32630 (1 paratype); SMF 32640 (1 paratype on SEM stub, DNA voucher Orbi 18); ZMBN 157433 (1 paratype, DNA voucher Orbi 3). Other material examined. ZMBN 157432 (3 spms). Diagnosis. An Orbiniella with segmental annulation pattern as follows: one narrow annulus between parapodia from parapodium 1 until 5 or 6 and two narrow annuli between parapodia from parapodium 5 or 6 until end of available fragment of the most complete specimen. Acicular spines short and stout, up to three in both noto- and neuropodia. Pygidium not observed. Type locality. Irminger Basin, SW Iceland, NE Atlantic, 62.9888, - 28.0950, 1588 m (Fig. 6). Description (based on type specimens). Holotype incomplete with 14 chaetigers, 3.0 mm long and 0.36 mm wide at level of chaetiger 6. Body elongated and narrow, uniformly wide. Pigmentation lacking in all analysed specimens. Prostomium broad with rounded anterior margin, without eyespots or nuchal organs (Fig. 7 A). Peristomium with two prominent achaetous segments, first segment shorter than second segment, distinctly separated from each other and first chaetiger by a narrow annulus (Fig. 7 A). Anterior chaetigers short, becoming longer and more square-shaped from chaetiger 7–10 onwards. Segmental annulation pattern: one narrow annulus between parapodia from parapodium 1 until 5 or 6 and two narrow annuli between parapodia from parapodium 5 or 6 until end of available fragment of most complete specimen (Fig. 7 E, F). Posterior part and pygidium not observed. Parapodia biramous, wider than long, with postchaetal notopodial lobes short, digitate with slightly narrowing basal part, from chaetiger 1 (Fig. 7 B). Postchaetal neuropodial lobes absent. Crenulated capillary chaetae and acicular spines present in both rami from chaetiger 1. Capillaries equal in length to body width and numerous (6–8 ...