Admetella cf. longipedata (McIntosh, 1885)

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

Admetella cf. longipedata (McIntosh, 1885) Fig. 22A

Diagnosis.

Four long-bodied specimens with <~ 62 segments, at least 24 pairs of elytrophores, all elytrae missing. Pharynx dark purple, with four plate-like falcigerous jaws, and ringed with 21 or 22 pairs of papillae. Prostomiums all badly degraded. Antennal styles all missing, median antenna ceratophore present, inserted in medial notch on prostomium, dorsal to scars of small lateral antennae inserted anteroterminally, antennal scales missing. Cephalic peaks absent. Palps long and robust, with longitudinal rows of very fine papillae. Facial tubercle present, rounded, located dorsal to ridged upper lip, between palp bases. Eyes absent. Low transverse nuchal fold present between first pair of elytrophores. Tentaculophores with chaetae. Parapodia subbiramous, well developed, flattened transversely, elongated (neuropodium 2 × longer than notopodium), with elongated acicular lobes and long cirriform subacicular processes, neuropodia not deeply split dorsally and ventrally, short notopodia arising from anterodorsal faces of parapodia. Neurochaetae flattened iridescent chaetae with pointed bare tips (often split) with rows of fine serrations along one side. Notochaetae all missing or absent.

Remarks.

Because of the poor state of prostomiums, it was not possible to determine the presence of antennal scales or sheaths between ceratophores of median and lateral antenna, which A. longipedata possesses. All specimens lacked notochaetae which were assumed to be broken off. In all other features, such as elongate parapodia with long acicular lobes and long cirriform subacicular processes, the position of antennae on prostomium, presence of a nuchal fold, numerous, long, flattened, transparent neurochaetae,> 20 pairs of elytra and> 50 body segments, the specimens resemble Admetella and are closer to A. longipedata than to A. brevis Levenstein, 1978, due to the presence of chaetae on the tentaculophore (see Fauchald 1972). Pettibone’s (1967) illustrations (and part of description) of A. longipedata are incorrect according to Fauchald (1972), who regards that description as belonging to A. hastigerens Chamberlin, 1919.

Records.

4 specimens. Suppl. material 1: op. 35 (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).