Osedaxwaadjum, 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 : 199-201

Osedaxwaadjum sp. nov.

urn:lsid:zoobank.org:act:382AE053-EDCF-4086-A819-2344D8CC40A8

Fig. 26

“ Osedax sp. nov. ” Gunton et al., 2021: 129–130 , fig. 27B, C

Holotype: AMW.53706, 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: NHMUKANEA 2022.400 , NHMUKANEA 2022.401 , NHMUKANEA 2022.402 , NHMUKANEA 2022.403 , NMV F253031 , NMV F253032 , same locality as holotype. DNA vouchers: NHMUKANEA 2022.400 ( COI, 16S) , AMW.53706 ( COI, 16S, 18S) , NHMUKANEA 2022.401 ( COI, 16S) , NHMUKANEA 2022.403 (16S) , NHMUKANEA 2022.402 ( COI) , NMV F253031 (16S) , NMV F253032 ( COI) .

Description. Female tubelong (25 mm, specimen NHMUK ANEA 2022.403), anteriorly thin, semi-transparent and appearing rounded and closed at the tip ( Fig. 26A ), posterior tube tough and creased. Females with crown of four palps fusedformuch of their length (6.8 mm in specimen NHMUK ANEA 2022.403), contracted within tubes and without obviouspinnulesbut slightlywrinkled andwithdistinct blood vessels in live specimens ( Fig. 26B ). Trunk ( Fig. 26C ) short in relation to the length of the palps (0.6 mm in specimen NHMUKANEA 2022.402). Oviduct extends from base of palps ( Fig. 26D ), opposite side of trunk bears a folded, wrinkled lobe ( Fig. 26E ). Ovisac not observed. Males 385 µm in length ( Fig. 26F ), bearing hooked chaetae anteriorly, and observed at various positions within female tubes.

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

Etymology. In the Arakwal Bundjalung language Waadjum Darrigan Jubal means “Whale Bone Grub”. In consultation with the Bundjalung of Byron Bay Aboriginal Corporation board of directors representing the Arakwal Bundjalung communities, we propose the scientific name “ Osedax waadjum ”.

Remarks. Genetic data confirms that these specimens comprise a new species that falls within the same clade as other nude palp Osedax species with good support ( Fig. 27 ). The position of Osedax waadjum sp. nov. appears basal in relation to all other nude palp species, with the exception of Osedax deceptionensis Taboada, Cristobo, Avila, Wiklund, & Glover, 2013 . Uncorrected COI genetic distances between O. waadjum sp. nov. and other Osedax species are a minimum of 14% (Table S17), while within speciesthey are less thanor equal to 0.4%. Osedaxwaadjum sp. nov. is described mainly on the basis of genetic data as many of the specimens were damaged during removal from the whale bones. The closed-top tube morphology of this species resembles that of Osedax lonnyi Rouse, Goffredi, Johnson, & Vrijenhoek, 2018 and Osedax jabba Rouse, Goffredi, Johnson, & Vrijenhoek, 2018 . Other nude palp Osedax species occupying a similar depth include Osedax antarcticus Glover, Wiklund, & Dahlgren, 2013 , Osedax docricketts Rouse, Goffredi, Johnson, & Vrijenhoek, 2018 , Osedax knutei Rouse, Goffredi, Johnson, & Vrijenhoek, 2018 , and Osedax westernflyer Rouse, Goffredi, Johnson, & Vrijenhoek, 2018 , described from the Southern Ocean or Eastern Pacific. Osedax docricketts and O. westernflyer also occur in Sagami Bay off Japan.

Figures

Figure 26. See caption on facing page.

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.