Paramphinome cf. australis Monro, 1930

Georgieva, Magdalena N., Wiklund, Helena, Ramos, Dino A., Neal, Lenka, Glasby, Christopher J. & Gunton, Laetitia M., 2023, The Annelid Community of a Natural Deep-sea Whale Fall off Eastern Australia, Records of the Australian Museum (Rec. Aust. Mus.) 75 (3), pp. 167-213 : 171-172

Paramphinome cf. australis Monro, 1930

Fig. 5

Paramphinome cf. australis Gunton et al., 2021: 21–22 , fig. 5C,D

Material examined. NHMUKANEA 2022.435 , AM W.52195 , AMW.52197 , IN2017_V03_100; 9 June 2017; off Byron Bay , NSW, Australia, beam trawl, start: 28.05°S 154.08°E, 999 m, end: 28.10°S 154.08°E, 1013 m. DNA vouchers: NHMUKANEA 2022.435 (COI, 16S, 18S), AM W.52195 (16S), WF_ AMP _2 (COI, 16S), AMW.52197 (16S).

Description. Descriptions based on AM W.52197. Body shape elongate ( Fig. 5A ), specimen complete, around 4 mm length. Eyes absent. Prostomium rounded. One median unpaired antenna ( Fig. 5B ), pair of lateral antennae. One or two pairs of strongly curved hooks on chaetiger 1 ( Fig. 5C ) depending on body size (smaller individualsone, larger individuals two). Arborescent branchiae beginning on chaetiger 4 to chaetiger 7 ( Fig. 5D ). Parapodia biramous. Notochaetae: capillary chaetae with step-like serrations and smooth unadorned spines. Notoacicula two per fascicle. Neurochaetae long thin capillaries with basal spurs, long thin capillaries no basal spurs, subdistally inflated bifurcate chaetae serrated prongs. Neuroacicula two per fascicle ( Fig. 5E ). Pygidium unadorned.

Distribution. IN2017_V03, Station 100. Pilot whale carcass, off Byron Bay, New South Wales, Australia in 999–1013 m.

Remarks. Specimen AMW.52197 closely resembles Paramphinome australis Monro, 1930 . Are-description of Paramphinome australis is given in Böggemann (2009). The current specimen differs from Paramphinome australis in the number of strongly curved hooks numbering 1–2 not 2–3 as in Böggemann (2009). There was nodifference in the thickness of notochaetae spines (according to Böggemann (2009) and Kudenov (1993) and fewer notoacicula and neuroacicula per fascicle werealsoobserved inour material. The typelocality of Paramphinome australis is the Southern Ocean off the South Orkney Islands at 244–344 m depth, while Böggemann’s (2009) re-description was based on samples from the Angola Basin at 3945–3992 m depth. The author states that the species is “known from Antarctic and Subantarctic regions recorded from subtidal to abyssal depths”. This broad bathymetric distribution suggests a species complex. Molecular data recovered our specimens, Paramphinome cf. australis , and Paramphinome jeffreysii McIntosh, 1868 (described from the Shetland Islands) as sister taxa in a well-supported monophyletic group (pp 1.0) ( Fig. 6 ); COI genetic distance between Paramphinome cf. australis and P. jeffreysii was 22% (Table S14). Unfortunately, no molecular data exists for Paramphinome australis and due to the large bathymetric and geographic range suggested for this species, we designate the current material as Paramphinome cf. australis until genetic data is obtained for P. australis .

Figures

Figure 5. Paramphinome cf. australis AM W.52197. (A) Whole body of specimen dorsal view scale bar 1 mm; (B) prostomium with one median antenna, scale bar is 50 μm; (C) strongly curved hooks on chaetiger 1, scale bar is 20 μm; (D) arborescent branchiae, scale bar is 20 μm; (E) neuroacicula, scale bar is 20 μm.

Figure 6. Phylogeny of theAmphinomidae family based on Bayesian analysis of the COI, 16S and 18S gene fragments.Numbers adjacent to nodes indicate posterior probabilities, and taxa for which sequences have been contributed by the present study are indicated in bold. Specimen voucher numbers are given after taxa names.