Anguillosyllis sp.

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

Anguillosyllis sp. Fig. 26D

Diagnosis.

Specimens small, <3.5 mm in length, 11 chaetigers, prostomium short, wider than long, with pair of oval pigmented nuchal organs posteriorly, eyes absent. Palps narrow, elongate, longer than prostomial length, fused for almost full length, with tip distally notched. Lateral antennae short, cirriform, wrinkled (not ovate), median antenna missing. Pharyngeal tooth absent, nine or ten terminal papillae around pharynx rim. Proventricle extending through segments 3-4, with an indistinct number of muscle bands (12-15?). Single pair of papilla-like tentacular cirri on peristomium. Dorsal cirri long, filiform, wrinkled, coiling; few remaining, absent or missing from chaetiger 2. Ventral cirri digitiform, short, inserted somewhat distally (more than midway) on parapodia. Parapodia elongate with distally rounded posterior lobes, retractile elongate postchaetal lobes not obvious (all retracted?), but presumably represented by a small dorsal papilla-like protuberance. Parapodial glands not evident. Chaetae all compound, long-bladed spinigerous chaetae and shorter-bladed falcigers with finely spinulose blades and unidentate tips. Emergent aciculae and simple chaetae not observed. Posterior end truncated, damaged on most specimens, with at least one pair of long lateral pygidial cirri present, but ventromedial pygidial cirri missing on all specimens.

Remarks.

Recently, a revision of the Anguillosyllis species from deep-water locations was published by Maciolek (2020). This author increased the number of nominal species described from four to 20 ( Read and Fauchald 2020) and determined that the number of chaetigers was a specific character. Accordingly, the only described species which possess a combination of 11 chaetigers, palps fused for most of their length as well as elongate, bladed, spinigerous, compound chaetae are the type species for the genus, A. capensis Day, 1963, A. capensis sensu Böggemann and Purschke (2005), and A. capensis sensu Böggemann (2009). These Australian specimens most resemble a description by Böggemann (2009) of specimens from the abyssal SE Atlantic Ocean (recorded from 3950-5655 m depth off western Africa), which Maciolek (2020, in Remarks for the genus diagnosis, p.15) considers to be two different species as well as different to A. capensis Day, 1963. Böggemann’s (2009) and Böggemann and Purschke’s (2005) west African specimens possess dorsal cirri on chaetiger 2 as well as simple chaetae in superior and inferior positions in some specimens, which our Australian specimens appear to lack.

For these Australian specimens, because we cannot determine the relative extent of the posterior parapodial lobes which are retracted completely (presumably, or are absent entirely), and because all dorsal cirri are missing from chaetiger 2 (or may be completely absent), it is not possible to determine whether these specimens are the same as one of the two species (described as one) of Böggemann (2009). It does not conform to any other nominal species’ descriptions and is likely to be new.

Records.

16 specimens. Suppl. material 1: ops 9, 16, 31, 33, 54, 79 (NHMUK). 11 specimens. Suppl. material 1: ops 16, 31, 33, 42, 54, 79 (AM).

Figures

Figure 26. Sabellidae, Syllidae, Terebellidae. Sabellidae A Sabellidae sp. 1 (AM W. 52133) B Sabellidae sp. 2 (AM W. 52214) C Potamethus cf. scotiae (AM W. 51585). Syllidae D Anguillosyllis sp. (AM W. 52625) E Exogone cf. heterosetosa (AM W. 52329) F Terebellidae (sensu stricto) (AM W. 50426). Scale bars: 1 mm (A, B, D, E); 5 mm (C, F).