identifier	taxonID	type	CVterm	format	language	title	description	additionalInformationURL	UsageTerms	rights	Owner	contributor	creator	bibliographicCitation
67E08243492658538452F012DC513449.text	67E08243492658538452F012DC513449.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Bathyeliasona oceanxplorer Chuar & Iesa & Raquib 2026	<div><p>Bathyeliasona oceanxplorer sp. nov.</p><p>Figs 2, 3, 4, 5, 6, 7; Tables 1, 2</p><p>Material examined.</p><p>Holotype. Indian Ocean • Abyssal plain between Christmas Island and the Cocos (Keeling) Islands, <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=101.586&amp;materialsCitation.latitude=-11.9829" title="Search Plazi for locations around (long 101.586/lat -11.9829)">Station CHR 23, Dive CHR 0597</a>; - 11.9829, 101.5860; depth 4977 m; 18 Oct. 2025; Suction sampler, ROV Chimaera operated from R/V OceanXplorer, NUS–OX Expedition (OXR 20251007); GenBank: PZ 946646 – PZ 946648, PZ 946871; ZRC.ANN.2366 .</p><p>Diagnosis.</p><p>Body with 18 segments; prostomial lobes anteriorly rounded, each with a slender, short frontal filament inserted anteriorly; eight pairs of elytra, with short, non-uniformly sized conical papillae along the posterior half of the margins; subacicular neurochaetae with distinct central rib on the distal half; nephridial papillae present from segment 5 onwards, all small; buccal bulb present; ventral pygidial lobes with weakly undulate distal margins.</p><p>Description.</p><p>Body 85 mm long, 48 mm wide, with 18 segments; robust, compact, dorsoventrally flattened. Dorsum of live specimen covered by large, overlapping, thick, semi-transparent elytra (Fig. 2 A – C). Body surface smooth, iridescent in vivo (Fig. 2 C – E); preserved specimen greyish in ethanol (Fig. 3 A). With eight pairs of elytra on segments 2, 4, 5, 7, 9, 11, 13, and 15, attached to prominent, bulbous elytrophores, completely covering the dorsum (Figs 2 A – C, 3 A). Elytra oval to subreniform, thick, with short, non-uniformly sized conical marginal papillae along the posterior half of the margin (Figs 2 C, 2 F, 2 G, 4 A – C); iridescent in vivo when illuminated (Fig. 2 C, F, G), opaque and greyish when preserved (Fig. 4). Cirrigerous segments with prominent cylindrical dorsal cirrophores, inserted on posterior side of notopodia (Fig. 5 C); cirrostyle tapering, sparsely papillate, extending beyond tips of neurochaetae (Fig. 5 A, B).</p><p>Prostomium bilobed; lobes pronounced, anteriorly rounded, with slender, short frontal filaments inserted anteriorly (Figs 2 E, 3 C – E). Eyes absent. A pair of nuchal organ pits dorsally on the posterior part of prostomial lobes, visible in live specimen, indiscernible after preservation (Figs 2 E, 3 C). Median antenna with ceratophore long and prominent, inserted in median notch, style lost (Figs 2 E, 3 C). Lateral antennae absent. Facial tubercle absent. Palps smooth, tapering, long, reaching segment 6 (Figs 2 C, 2 D, 3 A, 3 B).</p><p>Tentaculophores with chaetae (Figs 2 E, 3 C). Tentacular styles distally tapering, reaching segment 6, sparsely papillated, papillae small; dorsal style slightly longer than ventral (Figs 2 C, 2 D, 3 A, 3 B).</p><p>Pharynx long, dark grey, reaching segment 11, with nine pairs of subtriangular, equal-sized distal pharyngeal papillae (Fig. 3 M); two pairs of jaws, both with smooth margins (Fig. 3 L). An inverted buccal bulb at distal end of pharynx (Fig. 3 I, J).</p><p>Parapodia biramous, notopodia shorter than neuropodia (Fig. 5 A, C – E). Notopodia cylindrical; acicular lobe distally elongated, tapering (Fig. 5 E). Neuropodia large, subrectangular; acicular lobe distally elongated, digitiform (Fig. 5 A, D); post-chaetal lobe truncate (Fig. 5 C, E). Notochaetae ~ 50 per ramus, stouter than neurochaetae, distally straight to slightly curved, with numerous spinous rows on convex side, tips pointed and smooth (Figs 5 H, 5 I, 6 A – C). Neurochaetae numerous, distally greatly expanded and flattened, with serrated lateral margins (Figs 5 F, 5 G, 5 J – L, 6 D – J); supraacicular neurochaetae ~ 2 × as wide as subacicular neurochaetae (Fig. 5 F, G, J – L); subacicular neurochaetae with central rib distally (Fig. 5 J – L). Parapodia of last segment similar to preceding segments.</p><p>Buccal cirri inserted basally on neuropodia of segment 2, smooth, tapering, slightly longer than subsequent ventral cirri (Fig. 3 B, F). Ventral cirri on segments 3–18 short, inserted subdistally on neuropodia (Figs 3 B, 5 A).</p><p>Nephridial papillae present from segments 5–18, small, digitiform to subconical (Fig. 3 B, F); a rudimentary nephridial papilla on right parapodium of segment 4.</p><p>Pygidium terminal, with dorsal anus (Fig. 3 G); a pair of ventral pygidial lobes, distal margins weakly undulate (Fig. 3 H). Pygidial cirri inserted in a subovate depression, style tapering, sparsely papillate, papillae minute (Fig. 3 A, K). Left cirrus 60 mm long, much thicker and ~ 6 × longer than right cirrus, probably regenerating; detached during collection and retained in the same container (Fig. 3 A).</p><p>Phylogeny.</p><p>In the concatenated phylogeny based on COI, 16 S rRNA, 18 S rRNA, and 28 S rRNA, Bathyeliasona oceanxplorer sp. nov. was recovered within a well-supported Bathyeliasona clade (100 / 100; Fig. 7), where it was resolved as sister to B. nigra (98.9 / 100), with B. mariaae sister to this clade. Of the four valid species of Bathyeliasona, sequence data are available only for B. nigra and B. mariaae . Uncorrected pairwise COI p-distances between Bathyeliasona oceanxplorer sp. nov. and these two congeners were 17.7 % and 18.6 %, respectively. These results confirm the placement of the new species within Bathyeliasona and indicate that it is genetically well differentiated from its sequenced congeners.</p><p>Etymology.</p><p>The specific epithet oceanxplorer is used for the research vessel OceanXplorer, in recognition of its support for the expedition during which the type material was collected. The name is treated as a noun in apposition.</p><p>Distribution.</p><p>Eastern Indian Ocean, on the abyssal plain between Christmas Island and the Cocos (Keeling) Islands (Fig. 1).</p><p>Ecology.</p><p>Collected from the abyssal plain seafloor (4977 m) at water temperature of 1.2 ° C.</p><p>Behaviour.</p><p>When first observed through the ROV camera, the polynoid was stationary on the seafloor and showed no obvious movement, even when the ROV landed nearby. It attempted to move away only when the suction sampler approached and began drawing it in (Suppl. material 1).</p><p>Remarks.</p><p>Bathyeliasona oceanxplorer sp. nov. resembles B. abyssicola (Fauvel, 1913) and B. nigra (Hartman, 1967) in having 18 body segments (Table 2). However, the frontal filaments of both B. abyssicola and B. nigra are subulate, whereas those of B. oceanxplorer sp. nov. are slender and short (Fig. 3 D, E). In this character, the new species more closely resembles B. kirkegaardi (Uschakov, 1971), as both species have anteriorly rounded prostomial lobes with slender frontal filaments. Even so, B. oceanxplorer sp. nov. differs from B. kirkegaardi in having 18 (instead of 17) segments, the presence of a buccal bulb (not reported in the latter), and a different pygidial lobe shape (Table 2). The new species also resembles B. mariaae in having slender frontal filaments, the presence of nuchal organs, and subacicular neurochaetae with central rib, but differs in several aspects: the frontal filaments are shorter, reaching only ~ 1 / 2 the length of the median antenna ceratophore (Fig. 3 C), rather than reaching its distal end; the nuchal organs are situated near the posterior part of the prostomial lobes (Fig. 2 E), rather than on the mid-anterior part; and nephridial papillae are present (Fig. 3 F), rather than absent.</p></div>	https://treatment.plazi.org/id/67E08243492658538452F012DC513449	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Pensoft via Plazi	Chuar, Cheah Hoay;Iesa, Iffah;Raquib, Tashfia	Chuar, Cheah Hoay, Iesa, Iffah, Raquib, Tashfia (2026): A new species of Bathyeliasona (Annelida, Polynoidae) from the abyssal plain of the eastern Indian Ocean. ZooKeys 1293: 121-140, DOI: 10.3897/zookeys.1293.208455
