Sigalioninae sp. 1

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

Sigalioninae sp. 1

Diagnosis.

Most specimens incomplete and missing elytra. Largest complete specimen 13 mm long, 1 mm wide, for 68 chaetigers. Prostomium with single long median antenna with short ceratophore, auricles absent. Eyes absent. Lateral antennae absent from all specimens (or missing). Palps long, smooth, reaching to at least chaetiger 14, with short inner palpal sheaths. Tentacular segment fused to prostomium, with two pairs of tapering cirri, dorsal cirri as long as median antenna, ventral ones short; tentaculophores with spinulose capillary chaetae. Labial lobes on lateral lips not observed. Parapodia without long bracts or stylodes. Dorsal cirri absent from chaetiger 3. Branchiae not observed. Notochaetae all capillary, smooth or spinulose, very long posteriorly. Neurochaetae mostly all compound spinigers with canaliculate blades, ventralmost chaetae shorter, canaliculate, and with blunt tips. Most elytra missing, remaining ones small, round, thin, translucent, without marginal or other papillae, not overlapping dorsally. Ventral cirri subulate.

Remarks.

These specimens appear to lack lateral antennae completely, and have canaliculate spinigerous compound neurochaetae only, though some in the ventralmost position possess blunt tips. There are few genera of Sigalionidae that lack lateral antennae altogether: Mayella Hartmann-Schröder, 1959, known from a single specimen collected intertidally in El Salvador, which Eibye-Jacobsen et al. (2020) suggest is a juvenile polynoid, and most genera and species of Pholoinae , all of which possess short falcigerous neurochaetae. These specimens strongly resemble a sigalionin species because of the type of chaetae. They may represent juveniles of Leanira sp. which were present in the same samples.

Records.

70 specimens. Suppl. material 1: ops. 9, 16, 23, 31, 40, 42, 45, 54, 55, 76, 79, 96, 110, 134 (AM).