Osedax byronbayensis, Georgieva & Wiklund & Ramos & Neal & Glasby & Gunton, 2023

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 : 204

Osedax byronbayensis sp. nov.

urn:lsid:zoobank.org:act:D8AA2600-5820-4531-A012-4B3D1F4C0664

Fig. 28

Holotype: AMW.53707, 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 . Paratypes: NMV F253033 , NMV F253035 , same locality as holotype. DNA vouchers: AMW.53707 ( COI, 16S, 18S) , NMV F253033 ( COI) , NMV F253035 ( COI) .

Description. Holotype incomplete, represented bymajority of tube containing a fragment of tissue. Tube approximately 18 mm long, tapering anteriorly, and endingin aclosed point ( Fig. 28A ). Tube material is easily torn. No males observed on tube. Tissue present within tube is possibly a single palp approximately 4 mm long and sinuous, surface appears smooth ( Fig. 28B ). Specimen not observed alive.

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

Etymology. This species is named after the town of Byron Bay, Australia, off which this whale fall was discovered.

Remarks. Osedax byronbayensis sp. nov. is known only from three incomplete specimens, therefore a complete morphological description was not possible. Molecular data demonstrates the three specimens to belong to the same species with high support ( Fig. 27 ); uncorrected COI p -distances betweenthe three specimensare 0.4–0.6%. They arepositioned ina clade withother nude palp Osedax species and demonstrate a minimum uncorrected COI p-distance of 12.7% to other Osedax species (to Osedax ryderi Rouse, Goffredi, Johnson, & Vrijenhoek, 2018 ; TableS17). As with Osedax species Osedax crouchi Amon, Wiklund, Dahlgren, Copley, Smith, Jamieson, & Glover, 2014 , Osedax nordenskjoeldi Amon, Wiklund, Dahlgren, Copley, Smith, Jamieson, & Glover, 2014 , Osedax rogersi Amon, Wiklund, Dahlgren, Copley, Smith, Jamieson, & Glover, 2014 , and Osedax ventana Rouse, Goffredi, Johnson, & Vrijenhoek, 2018 , O. byronbayensis sp. nov. is described mainly on the basis of molecular data.

Figures

Figure 27. Phylogeny of the siboglinid genus Osedax based on Bayesian analysis of a combined dataset of the genes COI, 16S and 18S. Numbers adjacent to nodes indicate posterior probabilities, and taxa for which sequences have been contributed by the present study are indicated in bold. Clades containing individuals with nude, pinnulate or no palps are also highlighted.

Figure 28. Osedax byronbayensis sp. nov. holotype AM W.53707. (A) Ethanol-preserved holotype showing majority of tube, scale bar is 1 mm; (B) detail of palp inside tube (arrowed), scale bar is 500 µm.