Macellicephala 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

Macellicephala sp. 1

Diagnosis.

Small-bodied, <10 mm in length, with 18 segments, nine pairs elytrophores, on 2, 4, 5, 7, 9, 11, 13, 15, 17. Elytra all missing. Prostomium bilobed, lateral antennae and frontal filaments absent, median antenna elongate with large ceratophore; palps smooth, long, reaching to at least segment 6. Eyes absent, facial tubercle absent. Tentaculophores achaetous, tentacular styles long, smooth. Parapodia sub-biramous; notopodia reduced with elongate acicular lobe and few blunt-tipped notochaetae with many faint rows of low teeth (many specimens with notochaetae missing); neuropodia with elongated acicular lobe and long flattened neurochaetae with acutely pointed straight tips and serrations along both sides. Notochaetae slightly slenderer than neurochaetae. Dorsal tubercles indistinct. Dorsal cirrophores elongate. Ventral cirri attached mid-parapodium from segment 3. Body smooth, without papillae. Posteriorly, ventral keel absent; anus opens dorsally. Pharynx often dark purple, seen through the body wall anteriorly, with two pairs of smooth jaws and nine pairs of terminal papillae.

Remarks.

These specimens most resemble M. laubieri Reyss, 1971, described from the Mediterranean in 2665 m, because of the combination of species characters such as the long length of palps and tentacular cirri, lack of frontal filaments and facial tubercle, inconspicuous dorsal tubercles, the form of the noto- and neurochaetae, and lack of papillae on the body. However, because of the geographical distance of these specimens from the type locality of M. laubieri , we do not assign the name.

Records.

14 specimens. Suppl. material 1: ops. 23, 40, 45, 66, 76, 87, 103 (AM).