Neogyptis sp. nov. 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

Neogyptis sp. nov. 1 Fig. 12D

Diagnosis.

Specimens all incomplete. Prostomium subrectangular (broader than long), posteriorly with deep mid-dorsal incision; one pair lateral antennae, tips well defined, extending two thirds to just short of length of palps; one short mid-prostomial antenna. Eyespots not visible. Palps bi-articulate, palpostyle cylindrical, twice length palpophore. Proboscis with many cylindrical papillae two or three rows deep, each papilla cilia-tipped. Nuchal organs very conspicuous, light brown, extending from anterolateral prostomium and coalescing mid-posterodorsally. First four segments tentacular, achaetous, bearing eight pairs tentacular cirri, longest extending back to chaetigers 5 or 6. Parapodia biramous throughout, dorsal cirri slender tapered, ~ two thirds length parapodial lobes anteriorly, half length in mid body; ventral cirri slender distally attached, tapered, extending less than half length parapodial lobes. Notopodia bearing capillaries only. Neuropodia compound spinigers. Colour in ethanol yellow-white base, with dark brown band dorsally and laterally on all tentacular segments, and lighter brown nuchal organs.

Remarks.

The present material clearly falls within the concept of the tribe Amphidurini Pleijel, Rouse, Sundkvist & Nygren, 2012, which includes Amphiduros Hartman, 1959, Amphiduropsis Pleijel, 2001, Neogyptis Pleijel, Rouse, Sundkvist & Nygren, 2012, and questionably Parahesione Pettibone, 1956. Of these three genera the present specimens are closest to Neogyptis because of the terminal ring of proboscideal papillae and presence of a median antenna. The fine-tipped lateral cirri and cilia-tipped cylindrical papillae were clearly visible only in the formalin-fixed specimen (AM W.52351, see Suppl. material 1) and not in the ethanol-fixed material, indicating the value of this preservative for morphological studies.

Of the 12 species in the genus the only species currently known from the West Pacific is Neogyptis hinehina Pleijel, Rouse, Sundkvist & Nygren, 2012 from the Lau Basin, south of Tonga. However, this species has twisted noto- and neurochaetae, which were not observed in the present material. Therefore, the present material probably represents an undescribed species.

Records.

11 specimens. Suppl. material 1: ops. 23, 31, 45, 54, 55, 76, 79 (AM).

Figures

Figure 12. Hesionidae A Microphthalmus sp. B Microphthalmus sp., anterior end C Microphthalmus sp., pygidium D Neogyptis sp. nov. 1 (AM W. 52327) E Neogyptis sp. nov. 2 (AM W. 52436) F Vrijenhoekia ketea G cf. Vrijenhoekia sp. nov. 1 (AM W. 52453). Scale bars: 0.25 mm (A); 100 µm (B); 100 µm (C); 1 mm (E, F, G); 2 mm (D).