Nicon maculata Kinberg, 1865

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

Nicon maculata Kinberg, 1865

Diagnosis.

Longest tentacular cirri extending back to chaetiger 5-9. Maxillary and oral rings of pharynx entirely bare of papillae and paragnaths. Dorsal notopodial ligule similar size to acicular ligule throughout (not markedly reduced or expanded on posterior chaetigers). Prechaetal notopodial lobe absent. Neuropodial postchaetal lobe present on chaetigers 1- ~ 12. Ventral neuropodial ligule on posterior chaetigers reduced, up to half length of acicular neuropodial ligule. Notochaetae homogomph spinigers only (homogomph falcigers absent). Neuropodial dorsal fascicle fused falcigers absent.

Remarks.

Until the pharynx is dissected and found to be bare, this species is strikingly similar to Neanthes bassi and N. kerguelensis (McIntosh, 1885). Although Nicon maculata does have slightly longer tentacular cirri and the postchaetal neuropodial lobe (which is present in all three species) seems slightly longer and appears articulated or constricted in Nicon maculata where it meets the neuropodial lobe (see further comments for N. bassi , above). These taxa are otherwise very similar, and it is difficult to sustain the placement of Nicon maculata in a different genus as no such revision has yet been undertaken. Hutchings and Reid (1991) were the first to record Nicon maculata from Australia.

This record here at 2687-2821 m is the deepest record of this species that we are aware of. The species is also known from a single specimen (1391 m) in the GAB ( MacIntosh et al. 2018: additional file 2) and widely recorded in southeastern Australia, the vicinity of Heard Island, and on the Antarctic continental margin at depths 145-1650 m.

Records.

1 specimen. Suppl. material 1: op. 44 (AM).