Bathyeliasona nigra (Hartman, 1967b)

Gunton, Laetitia M., Kupriyanova, Elena K., Alvestad, Tom, Avery, Lynda, Blake, James A., Biriukova, Olga, Boeggemann, Markus, Borisova, Polina, Budaeva, Nataliya, Burghardt, Ingo, Capa, Maria, Georgieva, Magdalena N., Glasby, Christopher J., Hsueh, Pan-Wen, Hutchings, Pat, Jimi, Naoto, Kongsrud, Jon A., Langeneck, Joachim, Meissner, Karin, Murray, Anna, Nikolic, Mark, Paxton, Hannelore, Ramos, Dino, Schulze, Anja, Sobczyk, Robert, Watson, Charlotte, Wiklund, Helena, Wilson, Robin S., Zhadan, Anna & Zhang, Jinghuai, 2021, Annelids of the eastern Australian abyss collected by the 2017 RV ' Investigator' voyage, ZooKeys 1020, pp. 1-198 : 1

Bathyeliasona nigra (Hartman, 1967b) Fig. 22C

Diagnosis.

Specimens short-bodied, complete ones with 18 segments, eight pairs of elytra. Body colouration dark purple-black. Bilobed prostomium tapering anteriorly to subulate frontal filaments (lateral antennae absent). Median antenna on long ceratophore inserted mid-dorsally on prostomium, posterior to frontal filaments. Palps long, tapering, smooth. Tentaculophores with chaetae. Facial tubercle absent. Eyes absent. Dorsal tubercles indistinct/absent, dorsal cirri with papillated styles. Nephridial papillae large, wide, on segments 10-12, but small, cylindrical, on segments 5-9 and 13-18. Parapodia with distally elongate pre-acicular neuro- and notopodial lobes, neuropodial supra-acicular process absent. Notochaetae present, as thick as neurochaetae, stout, with numerous transverse spinous rows and blunt bare tips. Neurochaetae wide, flattened, with serrated lateral margins, tips bluntly pointed, unidentate.

Remarks.

Of the four species of Bathyeliasona ( Pettibone 1976; Bonifácio and Menot 2018), only Bathyeliasona nigra has 18 segments, tentacular cirri with smooth styles and notochaetae as thick as neurochaetae. Our material conforms closely with the description of Pettibone (1976).

Bathyeliasona nigra was also recorded from the GAB surveys 2013/2015, albeit as ' Lepidonotinae sp. 2' ( MacIntosh et al. 2018). Most specimens are missing chaetae (broken off), palps and styles of cirri and antenna. This species has been recorded previously from Antarctic waters in depths of ~ 2500 m ( Hartman 1967b), as well as from the Indian Ocean, in 3300-4360 m depth ( Kirkegaard 1995).

Records.

22 specimens. Suppl. material 1: ops. 33, 42, 53, 54, 65, 78, 89 (AM).

Figures

Figure 22. Polynoidae A Admetella cf. longipedata anterior end, dorsal view (AM W. 51461) B Austrolaenilla sp. anterior end, dorsal view (AM W. 52215) C Bathyeliasona nigra anterior end, dorsal view (AM W. 52216) D Eunoe cf. abyssorum anterior end, dorsal view (AM W. 51463) E Eunoe cf. opalina dorsal view and elytra (AM W. 51464). Scale bars: 1 mm (A, D, E); 3 mm (B); 2 mm (C).