Annelids of the eastern Australian abyss collected by the 2017 RV ' Investigator' voyage Author Gunton, Laetitia M. Australian Museum Research Institute, Sydney, Australia laetitia.gunton@austmus.gov.au Author Kupriyanova, Elena K. Australian Museum Research Institute, Sydney, Australia & Macquarie University, Sydney, Australia Author Alvestad, Tom Department of Natural History, University Museum of Bergen, University of Bergen, Bergen, Norway Author Avery, Lynda Museums Victoria, Melbourne, Australia Author Blake, James A. https://orcid.org/0000-0001-8217-9769 Aquatic Research & Consulting, Duxbury, Massachusetts, USA Author Biriukova, Olga Museum and Art Gallery of the Northern Territory, Darwin, Australia Author Boeggemann, Markus University of Vechta, Vechta, Germany Author Borisova, Polina P. P. Shirshov Institute of Oceanology, Russian Academy of Sciences, Moscow, Russia Author Budaeva, Nataliya Department of Natural History, University Museum of Bergen, University of Bergen, Bergen, Norway & P. P. Shirshov Institute of Oceanology, Russian Academy of Sciences, Moscow, Russia Author Burghardt, Ingo Australian Museum Research Institute, Sydney, Australia Author Capa, Maria https://orcid.org/0000-0002-5063-7961 Department of Biology, University of the Balearic Islands, Palma, Spain Author Georgieva, Magdalena N. Natural History Museum, London, UK Author Glasby, Christopher J. https://orcid.org/0000-0002-9464-1938 Museum and Art Gallery of the Northern Territory, Darwin, Australia Author Hsueh, Pan-Wen Department of Life Sciences, National Chung Hsing University, Taichung City, China Author Hutchings, Pat Australian Museum Research Institute, Sydney, Australia & Macquarie University, Sydney, Australia Author Jimi, Naoto https://orcid.org/0000-0001-8586-3320 National Institute of Polar Research, Tachikawa, Tokyo, Japan Author Kongsrud, Jon A. Department of Natural History, University Museum of Bergen, University of Bergen, Bergen, Norway Author Langeneck, Joachim https://orcid.org/0000-0003-3665-8683 Department of Biology, University of Pisa, Pisa, Italy Author Meissner, Karin Forschungsinstitut Senckenberg, DZMB, Hamburg, Germany Author Murray, Anna https://orcid.org/0000-0002-1765-1286 Australian Museum Research Institute, Sydney, Australia Author Nikolic, Mark Museums Victoria, Melbourne, Australia Author Paxton, Hannelore https://orcid.org/0000-0001-7086-5219 Australian Museum Research Institute, Sydney, Australia & Macquarie University, Sydney, Australia Author Ramos, Dino https://orcid.org/0000-0002-4069-5383 Natural History Museum, London, UK Author Schulze, Anja Texas A & M University at Galveston, Galveston, TX, USA Author Sobczyk, Robert Department of Zoology of Invertebrates and Hydrobiology, University of Lodz, Lodz, Poland Author Watson, Charlotte Museum and Art Gallery of the Northern Territory, Darwin, Australia Author Wiklund, Helena Natural History Museum, London, UK & Gothenburg Global Biodiversity Centre and University of Gothenburg, Gothenburg, Sweden Author Wilson, Robin S. https://orcid.org/0000-0002-9441-2131 Museums Victoria, Melbourne, Australia Author Zhadan, Anna Biological Faculty, Lomonosov Moscow State University, Moscow, Russia Author Zhang, Jinghuai South China Sea Environmental Monitoring Centre, State Oceanic Administration, Guangzhou, China text ZooKeys 2021 2021-02-24 1020 1 198 http://dx.doi.org/10.3897/zookeys.1020.57921 journal article http://dx.doi.org/10.3897/zookeys.1020.57921 1313-2970-1020-1 CC23B8CE8C8E473CBD8C44E74252A33D F6561609F0F15EE8907C94528CA44E4F Anguillosyllis sp. Fig. 26D Diagnosis. Specimens small, <3.5 mm in length, 11 chaetigers, prostomium short, wider than long, with pair of oval pigmented nuchal organs posteriorly, eyes absent. Palps narrow, elongate, longer than prostomial length, fused for almost full length, with tip distally notched. Lateral antennae short, cirriform, wrinkled (not ovate), median antenna missing. Pharyngeal tooth absent, nine or ten terminal papillae around pharynx rim. Proventricle extending through segments 3-4, with an indistinct number of muscle bands (12-15?). Single pair of papilla-like tentacular cirri on peristomium. Dorsal cirri long, filiform, wrinkled, coiling; few remaining, absent or missing from chaetiger 2. Ventral cirri digitiform, short, inserted somewhat distally (more than midway) on parapodia. Parapodia elongate with distally rounded posterior lobes, retractile elongate postchaetal lobes not obvious (all retracted?), but presumably represented by a small dorsal papilla-like protuberance. Parapodial glands not evident. Chaetae all compound, long-bladed spinigerous chaetae and shorter-bladed falcigers with finely spinulose blades and unidentate tips. Emergent aciculae and simple chaetae not observed. Posterior end truncated, damaged on most specimens, with at least one pair of long lateral pygidial cirri present, but ventromedial pygidial cirri missing on all specimens. Remarks. Recently, a revision of the Anguillosyllis species from deep-water locations was published by Maciolek (2020) . This author increased the number of nominal species described from four to 20 ( Read and Fauchald 2020 ) and determined that the number of chaetigers was a specific character. Accordingly, the only described species which possess a combination of 11 chaetigers, palps fused for most of their length as well as elongate, bladed, spinigerous, compound chaetae are the type species for the genus, A. capensis Day, 1963, A. capensis sensu Boeggemann and Purschke (2005) , and A. capensis sensu Boeggemann (2009) . These Australian specimens most resemble a description by Boeggemann (2009) of specimens from the abyssal SE Atlantic Ocean (recorded from 3950-5655 m depth off western Africa), which Maciolek (2020 , in Remarks for the genus diagnosis, p.15) considers to be two different species as well as different to A. capensis Day, 1963. Boeggemann's (2009) and Boeggemann and Purschke's (2005) west African specimens possess dorsal cirri on chaetiger 2 as well as simple chaetae in superior and inferior positions in some specimens, which our Australian specimens appear to lack. For these Australian specimens, because we cannot determine the relative extent of the posterior parapodial lobes which are retracted completely (presumably, or are absent entirely), and because all dorsal cirri are missing from chaetiger 2 (or may be completely absent), it is not possible to determine whether these specimens are the same as one of the two species (described as one) of Boeggemann (2009) . It does not conform to any other nominal species' descriptions and is likely to be new. Records. 16 specimens. Suppl. material 1: ops 9, 16, 31, 33, 54, 79 (NHMUK). 11 specimens. Suppl. material 1: ops 16, 31, 33, 42, 54, 79 (AM).