Nothria cf. paxtonae Imajima, 1999

Paxton, Hannelore, Budaeva, Nataliya & Gunton, Laetitia M., 2023, Amazing Diversity of Nothria (Annelida, Onuphidae) in the Australian Deep Sea, Records of the Australian Museum (Rec. Aust. Mus.) 75 (3), pp. 215-247 : 241

Nothria cf. paxtonae Imajima, 1999

Fig. 25 , Tables 2 , S 1

? Nothria paxtonae Imajima, 1999: 51 , figs 27–29.

Nothria cf. paxtonae .— Gunton et al., 2021:75, fig 16B.

Material examined (4). AM W.53844, IN 2017_ V 03_56 (3). AM W.53843, IN 2017_C01_207 (1).

Diagnosis. No eyes visible. Palpo- and antennophores with 2–3 rings, lateral antennae extending to chaetiger 5, median antenna to 6. Branchiae absent. First chaetiger and parapodia greatly enlarged, parapodia directed anteriorly, surpassing prostomium. Bidentate pseudocompound hooks only present on chaetigers 1 and 2; limbate chaetae from chaetiger 2; flat pectinate chaetae with about 12 teeth present on chaetiger 8; subacicular hooks from chaetiger 8–9. Tube with thin transparent lining, covered closely with foraminiferans.

Remarks. All of our specimens are anterior fragments, measuring 4–5 mm in length for 8–11 chaetigers, 1.0– 1.3 mm in width. The specimens were fixed in formalin, hence could not be sequenced. The alcohol-stored specimens are overall whitish without any pigmentation. The delicate jaws were not examined.

Nothria paxtonae was described from off Boso Peninsula to Suruga Bay, Japan, in 90–175 m depth, having small anterior eyespots and larger posterior eyes, pectinate chaetae from chaetiger 9, and uniquely for the genus, eight foliaceous papillae surrounding the anus .

Since our specimens are all incomplete, we were unable to confirm this identifying characteristic. Furthermore, none of our specimens appeared to have eyes and only one specimen has one pectinate chaeta on chaetiger 8. In view of these uncertainties, we are reporting the specimens as N. cf. paxtonae for the present time.

Budaeva & Paxton (2013) reported N. abyssia from off south-eastern Australia; it is very similar to N. paxtonae ; both species lack branchiae, have hooks present on the first two pairs of parapodia only, limbate chaetae starting from chaetiger 2 and have flat pectinate chaetae. They differ in that anal papillae are absent and pectinate chaetae have 17–20 teeth, starting on chaetiger 2–3 in N. abyssia whilst they have only 12 teeth and start on chaetiger 9 in N. paxtonae . However, they were not collected in the material of the present study.

Distribution. Off Jervis Marine Park, New South Wales, and Great Australian Bight, in 1772–2650 m depth ( Fig. 25 ).

Figures

Figure 25. Nothria cf.paxtonae Imajima, 1999.Map ofAustralian distribution; green dots sites of collection.