identifier	taxonID	type	CVterm	format	language	title	description	additionalInformationURL	UsageTerms	rights	Owner	contributor	creator	bibliographicCitation
03CFF8703B75A643FD8646FBCE05FC92.text	03CFF8703B75A643FD8646FBCE05FC92.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Anguillosyllis Day 1963	<div><p>Genus Anguillosyllis Day, 1963</p><p>Type species</p><p>Anguillosyllis capensis Day, 1963 .</p><p>Diagnosis (amended from Maciolek 2020)</p><p>Body very small, adults with limited and fixed number of chaetigers (8–11). Palps elongated, free to the base or fused partly to completely. Prostomium with three antennae, without eyes. Peristomium with one pair of tentacular cirri similar to or smaller than prostomial antennae. Parapodia uniramous, with anterior and posterior lobes developed to varying degrees; with superior (dorsal) lobe that may be contractile. Dorsal cirri may be absent on a variable number of chaetigers, with true absence on chaetiger 2 or on all chaetigers except chaetiger 1. Compound chaetae heterogomph, with falcigers and spiniger-like blades. Falcigers uni- or bidentate. Pharynx straight, eversible, with two (or three) crowns or sections, external one formed by pharyngeal sheath, distal one surrounded by several (10–12) soft papillae, tooth absent. Proventricle cylindrical, usually tapered posteriorly, muscle rows obscure; with associated glandular structure wrapped around post-ventricle. Pygidium with four cirri, two lateral, two ventromedial.</p><p>Remarks</p><p>While the distinct look of Anguillosyllis (elongated palps, low number of chaetigers) might have contributed to the lumping of similar species in the past, the use of molecular techniques has revealed a far greater diversity within this genus than previously thought (Drennan et al. 2025). Recent taxonomic work reported on characters that could help differentiate between different species (Aguado &amp; San Martín 2008; Barroso et al. 2017; Maciolek 2020). Most recently, Drennan et al. (2025) revealed novel and previously overlooked characters, best observed with the use of SEM, such as a complex form of prostomium, and absence of dorsal cirri on all but chaetiger 1. Here we rely predominantly on the characters used by Maciolek (2020), supplemented with SEM observations where possible. We caution against reliance on the characters such as size and shape of antennae or dorsal cirri, as these can differ even within a single specimen (Neal pers. obs.), likely due to preservation.</p><p>Update on previously reported characters</p><p>Palpal length can range from short (defined as similar in length to prostomium), to elongate (equaling multiple lengths of prostomium, usually no more than twice the length of prostomium), while the shape of palps can be pointed, conical or finger-like.</p><p>Prostomial antennae can vary in size (relative to prostomium and lateral antennae relative to median antenna) and in shape being papilliform, digitiform, club-shaped, cirriform or ovate, although caution is needed as stated above.</p><p>Tentacular cirri can range in size and shape similar to diversity of shape displayed by the antennae. Parapodia themselves can differ in length, and in shape, size and development of the associated parapodial lobes/projections. Ventral cirri showed some variation in length, thickness and the point of insertion on parapodium (median or subdistal).</p><p>Presence/absence of dorsal cirri on chaetiger 2 was discussed by Barroso et al. (2017) and Maciolek (2020) as an important character. Although dorsal cirri on chaetiger 2 are only rarely confirmed (they may be either absent or lost), the type species of the genus, A. capensis was originally described as bearing dorsal cirri on all chaetigers (Day 1963). However, the presence of the dorsal cirri on chaetiger 2 was not confirmed by examination of the holotype NHMUK. 1963.1.29, which is in extremely poor shape (Fig. 2). Maciolek (2020) reported the presence of dorsal cirri on chaetiger 2 on two specimens of A. palpata (Hartman, 1967) and one specimen of A. hampsoni Maciolek, 2020, with basal cirrophores also observed on chaetiger 2 in A. truebloodi . No specimens examined from UKSR material in the present study or previous study (Drennan et al. 2025) bore dorsal cirri on the second chaetiger.</p><p>True absence of dorsal cirri in other chaetigers. The true absence of dorsal cirri on chaetiger 2 has already been discussed above. Interestingly, SEM revealed true absence in all chaetigers but chaetiger 1 in Anguillosyllis dalgleishae sp. nov. This character state was already reported by Drennan et al. (2025) in Anguillosyllis cf. hessleri from the CCZ. Previously, based solely on examination using light microscopy, Maciolek (2020) suggested that in the following species the dorsal cirri are “missing” in all but chaetiger 1: Anguillosyllis acsara Maciolek, 2020, A. hadra Maciolek, 2020, A. taleola Maciolek, 2020, A. elegantissima Maciolek, 2020, A. enneapoda Maciolek, 2020, A. hessleri, A. inornata Maciolek, 2020 and A. sepula Maciolek, 2020 .</p><p>Prostomium has been given little attention in previous descriptions, usually described in simple terms such as dome-shaped, rounded, pentagonal, longer than wide, as long as wide etc. Based on observations from light microscopy, Maciolek (2020) reported that three species A. carolina Maciolek, 2020, A. denaria Maciolek, 2020 and A. taleola appear to have the prostomium in two parts. Our SEM observations showed that the prostomium is a complex structure composed of superimposed lobes of variable shapes, which may potentially differentiate species (see also Drennan et al. 2025).</p><p>Chaetae. Chaetae were previously considered falcigerous or spiniger-like, with variable length of blades, development of serration and number per chaetiger. Previously, only A. palpata was considered to have unique distinctly hooked chaetae (Maciolek 2020), with slightly hooked tips reported in A. truebloodi and A. hampsoni by Maciolek (2020). Our observations confirmed the presence of bidentate chaetae in Anguillosyllis villarae sp. nov. for the first time in this genus. Additionally, chaetal blades in Anguillosyllis can vary in thickness from narrow to flat and wide. The shafts of falcigerous chaetae in several anterior chaetigers in some species have been found to be denticulated, with denticles arranged in horizontal rows.</p><p>Internal glands. Maciolek (2020) reported on the shape and size of internal glands within parapodia, but we have found these difficult to observe and quantify. A stained circle of cells post-ventricle was observed when specimens were stained with Methyl Green (Neal pers. obs.).</p></div>	https://treatment.plazi.org/id/03CFF8703B75A643FD8646FBCE05FC92	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.		Plazi	Neal, Lenka;Drennan, Regan;Wiklund, Helena;Stewart, Eva C. D.;Rabone, Muriel;Dahlgren, Thomas G.;Glover, Adrian G.	Neal, Lenka, Drennan, Regan, Wiklund, Helena, Stewart, Eva C. D., Rabone, Muriel, Dahlgren, Thomas G., Glover, Adrian G. (2025): New species of Anguillosyllis Day, 1963 (Annelida, Syllidae) from polymetallic nodule exploration areas, eastern Clarion-Clipperton Zone, central Pacific Ocean. European Journal of Taxonomy 1026: 30-64, DOI: 10.5852/ejt.2025.1026.3105, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3105/13857
03CFF8703B79A658FD964733CF33FE0A.text	03CFF8703B79A658FD964733CF33FE0A.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Anguillosyllis dalgleishae Neal & Drennan & Wiklund & Stewart & Rabone & Dahlgren & Glover 2025	<div><p>Anguillosyllis dalgleishae sp. nov.</p><p>urn:lsid:zoobank.org:act: 9A52883F-A914-4190-8B89-10E9834ACA9E</p><p>Figs 3–5, 6A</p><p>Diagnosis</p><p>Body with 10 chaetigers. Prostomium in two parts, with three short antennae. Palps elongated, fused for at most ⅓–⅔ of their length. Parapodia with large conical dorsal lobes (flaps). Dorsal cirri on chaetiger 1 only. Heterogomph chaetae unidentate.</p><p>Etymology</p><p>The species name is dedicated to Claire Dalgleish, benthic operations lead on all cruises to the NORI-D area (C5a, C5d, C7a, C7b).</p><p>Material examined</p><p>Holotype</p><p>PACIFIC OCEAN – <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=-117.21716&amp;materialsCitation.latitude=12.0415" title="Search Plazi for locations around (long -117.21716/lat 12.0415)">Eastern Central Pacific</a>, Clarion Clipperton Fracture Zone • 12.0415° N, 117.2171667° W; 4094 m depth; 13 Mar. 2015; A.G. Glover, H. Wiklund, T. Dahlgren and M. Brasier leg.; Brenke Epibenthic Sledge; specimen GUID: 7195bc27-fb46-4f87-8c76-48266394b848; field ID; NHM_01867; GenBank 16S gene: PV579018; NHMUK ANEA 2024.2695.</p><p>Paratypes</p><p>PACIFIC OCEAN – Eastern Central Pacific, Clarion Clipperton Fracture Zone • 1 spec.; 12.37098333 ° N, 116.61365° W; 4160 m depth; 21 Feb. 2015; A.G. Glover, H. Wiklund, T. Dahlgren and M. Brasier leg.; USNEL Box Core; specimen GUID: 42eab9a3-1d5c-43ec-86e2-4f5aa47bd5f1; field ID NHM_00837; <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=-116.61365&amp;materialsCitation.latitude=12.370983" title="Search Plazi for locations around (long -116.61365/lat 12.370983)">GenBank</a> 16S gene: PV579009; NHMUK ANEA 2024.2686 • 1 spec.; 12.25733333 ° N, 117.3021667° W; 4302 m depth; 1 Mar. 2015; A.G. Glover, H. Wiklund, T. Dahlgren and M. Brasier leg.; Brenke Epibenthic Sledge; specimen GUID: 4be32c49-79e4-4cb1-a7b2-12b6265ff348; field ID NHM_01347A; <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=-117.30217&amp;materialsCitation.latitude=12.257334" title="Search Plazi for locations around (long -117.30217/lat 12.257334)">GenBank</a> COI gene: PV577541; 16S gene: PV579012; NHMUK ANEA 2024.2689 • 1 spec.; 12.3635 ° N, 116.681° W; 4233 m depth; 10 Mar. 2015; A.G. Glover, H. Wiklund, T. Dahlgren and M. Brasier leg.; Brenke Epibenthic Sledge; specimen GUID: b6584f26-950c-4506-b7e0-aec9cd37c46e; field ID NHM_01669A; <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=-116.681&amp;materialsCitation.latitude=12.3635" title="Search Plazi for locations around (long -116.681/lat 12.3635)">GenBank</a> 16S gene: PV579019; NHMUK ANEA 2024.2697 .</p><p>Other material</p><p>PACIFIC OCEAN – Eastern Central Pacific, Clarion Clipperton Fracture Zone • 1 spec.; 12.13366667 ° N, 117.292° W; 4122 m depth; 24 Feb. 2015; A.G. Glover, H. Wiklund, T. Dahlgren and M. Brasier leg.; Brenke Epibenthic Sledge; specimen GUID: d5d9b8f4-8717-43e7-9e6f- 422ce4acfdb6; field ID NHM_01021; <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=-117.292&amp;materialsCitation.latitude=12.133667" title="Search Plazi for locations around (long -117.292/lat 12.133667)">GenBank</a> 16S gene: PV579010; NHMUK ANEA 2024.2687 • 1 spec.; 12.00945 ° N, 117.1781167° W; 4144 m depth; 27 Feb. 2015; A.G. Glover, H. Wiklund, T. Dahlgren and M. Brasier leg.; USNEL <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=-117.178116&amp;materialsCitation.latitude=12.00945" title="Search Plazi for locations around (long -117.178116/lat 12.00945)">Box Core</a>; specimen GUID: 889e12a1-6e88-4987-9e8a- 1d758fd43ea3; field ID NHM_01201; GenBank 16S gene: PV579011; NHMUK ANEA 2024.2688 • 1 spec.; 12.45178333 ° N, 116.5122667° W; 4196 m depth; 4 Mar. 2015; A.G. Glover, H. Wiklund, T. Dahlgren and M. Brasier leg.; USNEL <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=-116.51227&amp;materialsCitation.latitude=12.451783" title="Search Plazi for locations around (long -116.51227/lat 12.451783)">Box Core</a>; specimen GUID: 502bcd95-9ec8-4ed2-acea- e630ede84474; field ID NHM_01508C; GenBank COI gene: PV577525; 16S gene: PV579013; NHMUK ANEA 2024.2690 • 1 spec.; 12.52121667 ° N, 116.69815° W; 4237 m depth; 8 Mar. 2015; A.G. Glover, H. Wiklund, T. Dahlgren and M. Brasier leg.; USNEL <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=-116.69815&amp;materialsCitation.latitude=12.521216" title="Search Plazi for locations around (long -116.69815/lat 12.521216)">Box Core</a>; specimen GUID: f4490e8c-6091- 4f27-85df-982e78912412; field ID NHM_01597; GenBank 16S gene: PV579014; NHMUK ANEA 2024.2691 • 1 spec.; 12.3635 ° N, 116.681° W; 4233 m depth; 10 Mar. 2015; A.G. Glover, H. Wiklund, T. Dahlgren and M. Brasier leg.; Brenke Epibenthic Sledge; specimen GUID: e40b2e1f-f476-4085- 9993-6dcf1221d8ad; field ID NHM_01657; <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=-116.681&amp;materialsCitation.latitude=12.3635" title="Search Plazi for locations around (long -116.681/lat 12.3635)">GenBank</a> 16S gene: PV579015; NHMUK ANEA 2024.2692 • 1 spec.; 12.17383333 ° N, 117.1928333° W; 4045 m depth; 11 Mar. 2015; A.G. Glover, H. Wiklund, T.vDahlgren and M. Brasier leg.; Brenke Epibenthic Sledge; specimen GUID: 589cb9f8-292c-4668- 940d-b2891384e4c0; field ID NHM_01773; <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=-117.19283&amp;materialsCitation.latitude=12.173833" title="Search Plazi for locations around (long -117.19283/lat 12.173833)">GenBank</a> 16S gene: PV579016; NHMUK ANEA 2024.2693 • 1 spec.; 12.17383333 ° N, 117.1928333° W; 4045 m depth; 11 Mar. 2015; A.G. Glover, H. Wiklund, T. Dahlgren and M. Brasier leg.; Brenke Epibenthic Sledge; specimen GUID: fb1eb56d-569c-4f11-83d0- 8c60ced37856; field ID NHM_01773A; <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=-117.19283&amp;materialsCitation.latitude=12.173833" title="Search Plazi for locations around (long -117.19283/lat 12.173833)">GenBank</a> 16S gene: PV579017; NHMUK ANEA 2024.2694 • 1 spec.; 12.00931667 ° vN, 117.3803° W; 4141 m depth; 15 Mar. 2015; A.G. Glover, H. Wiklund, T. Dahlgren and M. Brasier leg.; USNEL Box Core; specimen GUID: d6d4cdd0-e6ab-4e61-b9b0- e2eb3881e64a; field ID NHM_01990; GenBank 16S gene: PV664892; NHMUK ANEA 2024.2696 • 1 spec.; 13.93242102 ° N, 116.5110797° W; 4143.62 m depth; 5 Mar. 2020; A.G. Glover, H. Wiklund, G. Bribiesca Contreras and E. Simon Lledó leg.; USNEL Box Core; specimen GUID: 9f76d801-e1bb- 42d2-830d-0caec6103f72; field ID NHM_04729_ ESDS5; GenBank 18S gene: PV579029; NHMUK ANEA 2024.2698 • 1 spec.; 12.37908954 ° N, 116.5576715° W; 4196.02 m depth; 11 Mar. 2020; A.G. Glover, H. Wiklund, G. Bribiesca Contreras and E. Simon Lledó leg.; USNEL Box Core; specimen GUID: 2cb21b0d-bbf1-4c9e-a04e-728c72a9041d; field ID NHM_04731_ ECDS2; GenBank 16S gene: PV579020; NHMUK ANEA 2024.2699 .</p><p>Description</p><p>MEASUREMENTS AND APPEARANCE. Relatively large sized species, up to 3.25 mm in length for 10 chaetigers (Fig. 3B–C). Holotype NHMUK ANEA 2024.2695, posteriorly complete, 3.25 mm long and 0.45 mm wide at widest point for 10 chaetigers; right parapodia 9–10 removed for tissue sampling for DNA analysis. Paratype NHMUK ANEA 2024.2689, posteriorly complete, 2 mm long and 0.3 mm wide for 10 chaetigers, pygidial cirri missing, two left parapodia removed for tissue sampling for DNA analysis. Paratype NHMUK ANEA 2024.2697, posteriorly complete, 3 mm long and 0.4 mm wide for 10 chaetigers, pygidial cirri missing, three left parapodia removed for tissue sampling for DNA analysis. Paratype NHMUK ANEA 2024.2686, SEM specimen on stub (Fig. 4A–G), posteriorly incomplete and damaged, ~ 2 mm long and 0.3 mm wide for about 8 chaetigers. Other specimens in variable condition due to preservation or tissue sampling for DNA analysis; five specimens posteriorly complete with 10 chaetigers, ranging in length from 2 mm to 3 mm and up to 0.4 mm at widest point. Body relatively straight, tapering only at the first segment anteriorly, and from the pygidium posteriorly. Live specimen semi-translucent, without pigmentation (Fig. 3A); fixed specimen opaque, creamy white in ethanol (Fig. 3B–C).</p><p>PROSTOMIUM. Rounded, slightly wider than long under light microscope (Figs 3D, 5 A-inset); SEM shows differentiation into median quadrate lobe with deep notch on the posterior margin superimposed onto inferior rounded lobe (Figs 4A–B, 6A). Eyes absent. Prostomium bearing three short, digitiform antennae and two palps (Figs 3D–F, 4A–B, 5 A-inset). Antennae just under the length of the prostomium, with the median antenna slightly longer than lateral antennae and inserted posterio-dorsally on the prostomium; lateral antennae inserted more anteriorly. Palps smooth, somewhat elongate, approximately 1½ the length of the prostomium, and conical to somewhat finger-like in shape; palps sharply arcing ventrally from the base in almost all specimens and fused for at most ½–⅔ their length (degree of fusion not particularly clear) with distinct midline furrow and acute distal notch.</p><p>TENTACULAR SEGMENT. Achaetous, bearing two short ovate tentacular cirri, approximately ½ the length of the antennae and inserted laterally (Fig. 5A). Pharyngeal tube extending to chaetigers 2–3; proventricle spanning from chaetigers 2–4, barrel to lightbulb-shaped, tapered posteriorly, with possibly ~ 15–20 muscle cell rows, though this is difficult to discern through body wall of preserved specimens (Fig. 3B– C) and best observed in live specimen (Fig. 3A). Partially everted pharynx observed in only one specimen (Fig. 3G).</p><p>PARAPODIA. Somewhat short, rounded rectangular, and uniramous, with posterior-most two chaetigers somewhat thinner than on previous segments. Parapodia with large conical dorsal lobe (Figs 4C, 5C) and two short, papilliform lobes (Fig. 5A–C); posterior lobes smaller than anterior lobes on anterior-most chaetigers (Fig. 5C), but developed moving posteriorly, becoming subequal in length to the anterior lobe around chaetiger 6, and slightly exceeding the anterior lobe in size on subsequent chaetigers. Dorsal cirri present only on chaetiger 1, where long, filiform (Figs 3D–F, 4A–B, 5 A-insert); absent in other chaetigers. Ventral cirri short and conical with an expanded base, inserted midway along the parapodia (Figs 3H, 5A–B). Several pointed acicula per parapodium visible, with tips non emergent (Fig. 5E, marked by arrow). Each parapodium bearing dense bundles of numerous compound heterogomph chaetae, bundles becoming slightly sparser moving posteriorly, chaetae falcigerous to spiniger-like (Fig. 4F–G). Falcigerous chaetae of chaetigers 1–4 with denticulated shafts, with denticles arranged in irregular horizontal rows (Fig. 4D), from chaetiger 5 with shafts indistinctly denticulated or smooth (Fig. 4E). Blades finely serrated, unidentate decreasing in length dorso-ventrally, ranging from elongate, slender spiniger-like to shorter falcigers (Figs 4F–G, 5D), with blades of the longest spiniger-like chaetae 230–250 µm, and shortest falcigers 25–30 µm; chaetae emerge from semicircular flap that extends from posterior lobe ventrally towards the base of the parapodium.</p><p>PYGIDIUM. Conical to rounded; with four appendages; lateral cirri missing, ventromedial often missing, when present long, curled and filiform (Fig. 3I).</p><p>Reproductive information</p><p>Three specimens ovigerous; eggs visible through body cavity wall in all specimens between chaetigers 6–10, eggs irregularly shaped, ~50 µm in diameter (Figs 3A, 5F).</p><p>Genetic data</p><p>Specimens (n = 14) assigned to A. dalgleishae sp. nov. form a clade (Supp. file 3: Fig. S1, Supp. file 4: Fig. S2), with low intraspecific divergence across all sequences (maximum intraspecific p-distance/ K2P 0.5/0.5% for 16S and 1.3/1.3% for COI). Sequences matched with high % identity (99.7–100%) in blastn search and 0–0.3% in both p-distance and K2P to a 16S sequence of an unidentified Anguillosyllis specimen (accession number: MK971075; ID: Anguillosyllis sp. 43 PB voucher 021-BGR-0045) (see Fig. 7) collected from the BGR contract area of the Eastern CCZ, published in Bonifácio et al. (2020). In terms of the nuclear 18S gene, A. dalgleishae was also well defined, differing from other Anguillosyllis sequences by a minimum of five ( A. cf. hessleri sp. NHM_552 NHMUK2024.1002, A. capensis ZMH _ P25593, A. capensis ZMH _P25594) and a maximum of 16 ( A. capensis ZMH _P25588) mutations (1543 bp sequence).</p><p>Remarks</p><p>Morphologically, the new species can be distinguished from all other currently known species by the combination of the following characters: body with 10 chaetigers, presence of very large conical dorsal lobes (flaps) in parapodia and presence of dorsal cirri on chaetiger 1 only. Anguillosyllis dalgleishae sp. nov. can be distinguished from seven of the currently known species with 10 chaetigers by the presence of large parapodial dorsal lobes. Such lobes are currently known in only three species, that all possess 11, not 10 chaetigers: A. palpata, A. hampsoni and CCZ species A. truebloodi . Further, SEM confirmed the presence of dorsal cirri on chaetiger 1 only, a character currently confirmed by SEM only in other CCZ specimens assigned to Anguillosyllis cf. hessleri by Drennan et al. (2025). Maciolek (2020) using light microscopy considered such distribution as dorsal cirri “missing” in all but first segments.</p><p>0.2</p><p>However, given our observations, it may be the case of true absence in the following 10 chaetigers bearing species: A. taleola, A. sepula and A. elegantissima .</p><p>Distribution</p><p>Eastern CCZ: UK-1 and OMS exploration areas, depth ~ 4200 m. Also, BGR area (Bonifácio et al. 2020).</p></div>	https://treatment.plazi.org/id/03CFF8703B79A658FD964733CF33FE0A	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.		Plazi	Neal, Lenka;Drennan, Regan;Wiklund, Helena;Stewart, Eva C. D.;Rabone, Muriel;Dahlgren, Thomas G.;Glover, Adrian G.	Neal, Lenka, Drennan, Regan, Wiklund, Helena, Stewart, Eva C. D., Rabone, Muriel, Dahlgren, Thomas G., Glover, Adrian G. (2025): New species of Anguillosyllis Day, 1963 (Annelida, Syllidae) from polymetallic nodule exploration areas, eastern Clarion-Clipperton Zone, central Pacific Ocean. European Journal of Taxonomy 1026: 30-64, DOI: 10.5852/ejt.2025.1026.3105, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3105/13857
03CFF8703B62A65FFDBF45B4C9CCFB8D.text	03CFF8703B62A65FFDBF45B4C9CCFB8D.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Anguillosyllis finnelli Neal & Drennan & Wiklund & Stewart & Rabone & Dahlgren & Glover 2025	<div><p>Anguillosyllis finnelli sp. nov.</p><p>urn:lsid:zoobank.org:act: 1E961327-01B3-4D90-8227-1C13C8756D03</p><p>Figs 6B, 8–12</p><p>Diagnosis</p><p>Body with 11 chaetigers. Prostomium in two parts, with three short antennae. Palps elongated, free to the base. Parapodia with large conical dorsal lobes (flaps). Dorsal cirri absent in chaetiger 2. Heterogomph chaetae unidentate.</p><p>Etymology</p><p>The species name is dedicated to Cletus Finnell, Able Seaman on the RV Melville on the October 2013 cruise ‘ABYSSLINE AB01’.</p><p>Material examined</p><p>Holotype</p><p>PACIFIC OCEAN – <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=-116.70309&amp;materialsCitation.latitude=13.79335" title="Search Plazi for locations around (long -116.70309/lat 13.79335)">Eastern Central Pacific</a>, Clarion Clipperton Fracture Zone • 13.79335 ° N, 116.7030833° W; 4081 m depth; 11 Oct. 2013; A.G. Glover, H. Wiklund, T. Dahlgren and M. Georgieva leg.; USNEL Box Core; specimen GUID: 6d7ef8a1-9fa4-4eec-aca2-f68b1ace677b; field ID NHM_00093; GenBank COI gene: PV577530; 16S gene: PV579023; 18S gene: PV579030; NHMUK ANEA 2024.2720.</p><p>Paratypes</p><p>PACIFIC OCEAN – Eastern Central Pacific, Clarion Clipperton Fracture Zone • 1 spec.; 10.33079203 ° N, 117.1940202° W; 4290.89 m depth; 1 Jun. 2021; H. Wiklund, R. Drennan, C. Boolukos and G. Bribiesca Contreras leg.; USNEL Box Core; specimen GUID: c3b77851-d8d0-4a33-9f2b- 2a993391f41d; field ID; NHM_08730A; GenBank COI gene: PV577528; NHMUK ANEA 2024.2717 • 1 spec.; 10.35561637 ° N, 117.1686897° W; 4280 m depth; 11 Nov. 2020; H. Wiklund, R. Drennan, C. Boolukos and G. Bribiesca Contreras leg.; USNEL Box Core; specimen GUID: 654e0cbb-ac72- 4aec-93b0-a24302d3e16c; field ID NHM_05880; GenBank COI gene: PV664495; NHMUK ANEA 2024.2713 .</p><p>Other material</p><p>PACIFIC OCEAN – Eastern Central Pacific, Clarion Clipperton Fracture Zone • 1 spec.; 12.36565642 ° N, 116.7520565° W; 4159.33 m depth; 10 Mar. 2020; A.G. Glover, H. Wiklund, G. Bribiesca Contreras and E. Simon Lledó leg.; USNEL Box Core; specimen GUID: 89b42808-8b28-431e-b4d1- 7c7b486289b7; field ID NHM_04733_ ECDS4; GenBank COI gene: PV577526; 16S gene: PV579021; NHMUK ANEA 2024.2714 • 1 spec.; 12.38927437 ° N, 116.6362959° W; 4179.39 m depth; 11 Mar. 2020; A.G. Glover, H. Wiklund, G. Bribiesca Contreras and E. Simon Lledó leg.; USNEL Box Core; specimen</p><p>GUID: c2db9a70-9ccb-4d7e-abbf-4bef0404844c; field ID NHM_04741_ ECDS4; GenBank 16S gene: PV579022; NHMUK ANEA 2024.2715 • 1 spec.; 10.35780083 ° N, 117.1593114° W; 4284 m depth; 13 Nov. 2020; H. Wiklund, R. <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=-117.15931&amp;materialsCitation.latitude=10.3578005" title="Search Plazi for locations around (long -117.15931/lat 10.3578005)">Drennan</a>, C. Boolukos and G. Bribiesca Contreras leg.; USNEL Box Core; specimen GUID: 68b5e2d7-8061-4f19-adad-b577c49fb335; field ID NHM_08783_HW01; GenBank COI gene: PV577529; NHMUK ANEA 2024.2718 • 1 spec.; 10.33498329 ° N, 117.1741855° W; 4286 m depth; 6 Nov. 2020; H. Wiklund, R. <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=-117.17419&amp;materialsCitation.latitude=10.334983" title="Search Plazi for locations around (long -117.17419/lat 10.334983)">Drennan</a>, C. Boolukos and G. Bribiesca Contreras leg.; USNEL Box Core; specimen GUID: 8a93a352-604b-420f-b328-930c84d540cf; field ID NHM_08789_HW05; GenBank COI gene: PV664496; NHMUK ANEA 2024.2719 • 1 spec.; 10.35561637 ° N, 117.1686897° W; 4280 m depth; 11 Nov. 2020; H. Wiklund, R. <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=-117.168686&amp;materialsCitation.latitude=10.355617" title="Search Plazi for locations around (long -117.168686/lat 10.355617)">Drennan</a>, C. Boolukos and G. Bribiesca Contreras leg.; USNEL Box Core; specimen GUID: 04898df3-ab82-4b5d-8c82-7f0a5a396eac; field ID NHM_08801_HW03; GenBank COI gene: PV577527; NHMUK ANEA 2024.2716 • 1 spec.; 10.333014 ° N, 117.18551° W; 4281 m depth; 12 Feb. 2022; H. Wiklund, C. Boolukos, E. Stewart and A. Bessell leg.; USNEL Box Core; specimen GUID: 15c30fcb-cfdb-46c1-9066-f6eb52c4eb09; field ID NHM_10334_ CB3; GenBank COI gene: PV577532; NHMUK ANEA 2024.2722 • 1 spec.; 10.353342 ° N, 117.242837° W; 4296 m depth; 19 Nov. 2022; H. Wiklund, C. Boolukos, E. Stewart and A. Bessell leg.; USNEL Box Core; specimen GUID: 1cd18a15-4081-482f-b380-418cbe9a20e9; field ID NHM_10372_ CB06; GenBank COI gene: PV664497; NHMUK ANEA 2024.2723 • 1 spec.; 13.7309 ° N, 126.2041° W; 4704 m depth; 20 Feb. 2023; A.G. Glover, E. Stewart, G. Bribiesca Contreras and E. Simon Lledó leg.; USNEL Box Core; specimen GUID: f7d6faae-4c53-4fcd-a168-e55f53d3201c; field ID NHM_10602_GB01; <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=-126.2041&amp;materialsCitation.latitude=13.7309" title="Search Plazi for locations around (long -126.2041/lat 13.7309)">GenBank</a> COI gene: PV577531; NHMUK ANEA 2024.2721 .</p><p>Description</p><p>MEASUREMENTS AND APPEARANCE. Moderately sized species, up to 2 mm in length for 11 chaetigers (Fig. 8A–B). Holotype NHMUK ANEA 2024.2720, now posteriorly incomplete due to tissue sampling for DNA, ~ 1.65 mm long and 0.25 mm wide for 7 chaetigers (Fig. 9A, C); live specimen presented with complete body with 11 chaetigers (Fig. 9A). Paratype NHMUK ANEA 2024.2717, now posteriorly incomplete with 9 chaetigers, 1.8 mm long and 0.3 mm wide at widest point (Fig. 8B). Paratype NHMUK ANEA 2024.2713, SEM specimen on stub, posteriorly incomplete and damaged, ~ 1.55 mm long and 0.25 mm wide for 7 chaetigers (Fig. 10A). Other specimens in variable condition, usually posteriorly incomplete due to fragmentation or tissue sampling for DNA, where complete body with 11 chaetigers. Body somewhat dorsoventrally flattened, tapering slightly from chaetiger 4 anteriorly. Live specimen semi-translucent, without pigmentation (Fig. 9A); fixed specimen opaque, creamy white to pale yellow in ethanol (Figs 8A–B, 9B).</p><p>PROSTOMIUM. Oval, wider than long; differentiation of median lobe visible even under light microscopy in holotype (Fig. 9D); median lobe broadly pentagonal, anteriorly with two broad peaks (Figs 6B, 9D). Eyes absent. Prostomium bearing three short, digitiform to club-shaped antennae and two palps (Figs 9E– F, 10A–C). Antennae slightly shorter than the prostomium; median antenna club shaped (Fig. 9E), slightly longer than lateral antennae, and inserted posterio-dorsally on the prostomium; lateral antennae digitiform (Fig. 9F), inserted more anteriorly. Palps ~ 1.5 the length of prostomium, digitiform, thick and distally rounded, free to the base when fully extended (Figs 9C, 10A–D); curled ventrally in holotype, obscuring their true shape (Fig. 9A–B, D).</p><p>TENTACULAR SEGMENT. Achaetous, bearing two, very short, papilliform tentacular cirri,&gt;⅓ the length of the antennae and inserted laterally (Figs 9G, 10B). Pharyngeal tube extending to chaetiger 3, unarmed; proventricle spanning from chaetigers 3–5, barrel-shaped; number of muscle cell rows mostly obscured by body wall in preserved specimens, best observed in live specimen (Fig. 9A).</p><p>PARAPODIA. Long, rectangular, and uniramous. Parapodia with distally rounded, large conical dorsal lobe (Figs 10A–B, 11A) and two short papilliform lobes with anterior and posterior lobes of similar size (Fig. 11B). Dorsal cirri missing, SEM shows presence of cirrophores on all chaetigers, except for chaetiger 2 where truly absent (Fig. 10A–B). Ventral cirri conical, and short approximately half the length of the antennae, inserted midway to ⅔ along the length of the parapodia moving away from the body (Fig. 11C). At least three acicula per parapodium, two with emergent tips. Each parapodium bearing dense bundles of numerous compound heterogomph chaetae (Fig. 11A), with chaetal bundles becoming somewhat sparser posteriorly. Anterior falcigerous chaetae with denticulated shafts, denticles arranged in irregular horizontal rows (Fig. 12A); other chaetae with smooth shafts and finely serrated, unidentate blades decreasing in length dorso-ventrally, ranging from elongate, slender spiniger-like to shorter falcigers (Figs 11D–E, 12B–C). Blades of the longest spiniger-like chaetae ~ 170 µm, and shortest falcigers ~20 µ m. Tips of compound chaetae blunt, unidentate, at most gently hooked (Fig. 12B–C).</p><p>PYGIDIUM. Damaged; pygidial appendages missing.</p><p>Genetic data</p><p>Specimens (n = 11) assigned to A. finnelli sp. nov. form a clade (Supp. file 3: Fig. S1, Supp. file 4: Fig. S2), with low intraspecific divergence across all sequences (maximum intraspecific p-distance/K2P distance 0.5/0.5% for 16S and 1.9/1.9% for COI). Sequences matched with high % identity (99–100%) in blastn search and by intraspecific distance (maximum p-distance/K2P 1.8/1.8%) to a COI sequence of an unidentified Anguillosyllis specimen (accession number: MK971075; ID: Anguillosyllis sp. 244_PB voucher 088-IOM-0246) (Fig. 7) collected from the IOM contract area of the Eastern CCZ, published in Bonifácio et al. (2020). In combined analyses (Fig. 7), this species is close to a polytomy consisting of Anguillosyllis villarae sp. nov. and GenBank sequences identified as Anguillosyllis sp. MTA_2011 from Costa Rica (accession numbers 18S: JF903571; 16S: JF903680; COI: JF903756) published in Aguado et al. (2012). However, minimum interspecific p-distance/K2P of 14.4/16% 16S, and 16.1/18.3% COI were observed between these species and A. finnelli, while in an alignment of nuclear 18S (1630 bp), A. finnelli differed by two and four mutations from A. villarae sp. nov and Anguillosyllis sp. MTA_2011 respectively.</p><p>Remarks</p><p>The new species belongs to the group of Anguillosyllis with 11 chaetigers, well-developed parapodial lobes and palps free to a large extent, although this character is difficult to establish when palps are curled up (Neal pers. obs.). Of the known species, Anguillosyllis truebloodi also shares such characters, and also the CCZ distribution (DOMES site, Wilson 2017). However, the new species can be easily distinguished by the true absence of dorsal cirri on chaetiger 2 as revealed by SEM (Fig. 10B), which is present in A. truebloodi . Maciolek (2020) also reported palps as fused halfway to the base in A. truebloodi, whilst these are free to the base in the new species (Fig. 10A, D), although from certain angles, particularly where bent, the palps may appear fused. Another similar species is Anguillosyllis palpata with type locality in the Drake Passage in relatively shallow depths of 384–494 m, which has since been widely reported worldwide, including abyssal depths (Maciolek 2020). Morphological variation in specimens identified as A. palpata has been reported by Maciolek (2020), but in the absence of molecular data, species differentiation is difficult. The species newly reported here differs from A. palpata in the form of the chaetae, which are distinctly hooked in A. palpata, but not in the new species, in which they are at most gently hooked (Figs 11D, 12B–C), absence of large postchaetal lobes and true absence of dorsal cirri on chaetiger 2 (Fig. 10B).</p><p>Distribution</p><p>Eastern CCZ: NORI-D exploration area, depth ~ 4300 m; UK-1 exploration area, depth ~ 4200 m; OMCO site, depth ~ 4700 m. Also, IOM area (Bonifácio et al. 2020).</p></div>	https://treatment.plazi.org/id/03CFF8703B62A65FFDBF45B4C9CCFB8D	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.		Plazi	Neal, Lenka;Drennan, Regan;Wiklund, Helena;Stewart, Eva C. D.;Rabone, Muriel;Dahlgren, Thomas G.;Glover, Adrian G.	Neal, Lenka, Drennan, Regan, Wiklund, Helena, Stewart, Eva C. D., Rabone, Muriel, Dahlgren, Thomas G., Glover, Adrian G. (2025): New species of Anguillosyllis Day, 1963 (Annelida, Syllidae) from polymetallic nodule exploration areas, eastern Clarion-Clipperton Zone, central Pacific Ocean. European Journal of Taxonomy 1026: 30-64, DOI: 10.5852/ejt.2025.1026.3105, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3105/13857
03CFF8703B65A652FDBD403EC918FB8C.text	03CFF8703B65A652FDBD403EC918FB8C.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Anguillosyllis villarae Neal & Drennan & Wiklund & Stewart & Rabone & Dahlgren & Glover 2025	<div><p>Anguillosyllis villarae sp. nov.</p><p>urn:lsid:zoobank.org:act: E0177D9E-D221-48C7-A76C-2804FD4C469C</p><p>Figs 6C, 13–16</p><p>Diagnosis</p><p>Body with 10 chaetigers. Prostomium in two parts, with three short antennae. Palps elongated, free to the base. Parapodia with large conical dorsal lobes (flaps). Heterogomph chaetae unidentate with some tips hooked or with tips bidentate; some chaetae with wide strap-like blades.</p><p>Etymology</p><p>The species name is dedicated to Lucía Villar Muñoz a member of the science party on expeditions C5a, C5d, C7a, and C7b to the NORI-D area, particularly for her work slicing and sieving boxcore samples.</p><p>Material examined</p><p>Holotype</p><p>PACIFIC OCEAN – <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=-117.220795&amp;materialsCitation.latitude=10.354901" title="Search Plazi for locations around (long -117.220795/lat 10.354901)">Eastern Central Pacific</a>, Clarion Clipperton Fracture Zone • 10.354901 ° N, 117.220794° W; 4273.8 m depth; 23 Nov. 2020; H. Wiklund, R. Drennan, C. Boolukos and G. Bribiesca Contreras leg.; USNEL Box Core; specimen GUID: aa8735af-ee3a-456f-bc57-888dd874e7fc; field ID; NHM_08811; GenBank COI gene: PV577536; 16S gene: PV579024; 18S gene: PV579032; NHMUK ANEA 2024.2704.</p><p>Paratypes</p><p>PACIFIC OCEAN – Eastern Central Pacific, Clarion Clipperton Fracture Zone • 1 spec.; 10.32909125 ° N, 117.1971482° W; 4281 m depth; 9 Nov. 2020; H. Wiklund, R. Drennan, C. Boolukos and G. Bribiesca Contreras leg.; USNEL Box Core; specimen GUID: c382ab84-7641-40bb-91db-</p><p>107aa41c8eee; field ID NHM_05657; GenBank COI gene: PV577533; NHMUK ANEA 2024.2701 • 1 spec.; 10.34811115 ° N, 117.1706608° W; 4282.6 m depth; 17 May. 2021; H. Wiklund, R. Drennan, C. Boolukos and G. Bribiesca Contreras leg.; USNEL Box Core; specimen GUID: 2280eace-04fb- 430a-aa3f-d2163f629c86; field ID NHM_07689B; GenBank COI gene: PV577537; NHMUK ANEA 2024.2706 .</p><p>Other material</p><p>PACIFIC OCEAN – Eastern Central Pacific, Clarion Clipperton Fracture Zone • 1 spec.; 10.33498329 ° N, 117.1741855° W; 4286 m depth; 6 Nov. 2020; H. Wiklund, R. <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=-117.17419&amp;materialsCitation.latitude=10.334983" title="Search Plazi for locations around (long -117.17419/lat 10.334983)">Drennan</a>, C. Boolukos and G. Bribiesca Contreras leg.; USNEL Box Core; specimen GUID: 8a50f3cb-93de-4aa6-8792- cac45d2b2137; field ID NHM_05399; GenBank 16S gene: PV579028; NHMUK ANEA 2024.2712 • 1 spec.; 10.3861134 ° N, 117.1309018° W; 4308 m depth; 12 Nov. 2020; H. Wiklund, R. <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=-117.130905&amp;materialsCitation.latitude=10.386113" title="Search Plazi for locations around (long -117.130905/lat 10.386113)">Drennan</a>, C. Boolukos and G. Bribiesca Contreras leg.; USNEL Box Core; specimen GUID: bc633595-9ba5- 4320-a0c8-e0022060eac7; field ID NHM_05908; GenBank 16S gene: PV579025; NHMUK ANEA 2024.2705 • 1 spec.; 10.33426964 ° N, 117.1901234° W; 4287.72 m depth; 12 May. 2021; H. Wiklund, C. Boolukos, M. Rabone and G. Bribiesca-Contreras leg.; USNEL Box Core; specimen GUID: 50527b56- 3f4d-430f-929b-fa4d91b1d858; field ID NHM_06940; <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=-117.190125&amp;materialsCitation.latitude=10.33427" title="Search Plazi for locations around (long -117.190125/lat 10.33427)">GenBank</a> 16S gene: PV579027; NHMUK ANEA 2024.2711 • 1 spec.; 10.37726533 ° N, 117.1558078° W; 4302.03 m depth; 14 May. 2021; H. Wiklund, C. Boolukos, M. Rabone and G. Bribiesca Contreras leg.; USNEL Box Core; specimen GUID: 45112357-3af9-4c7f-8c93-d014c68f64ca; field ID NHM_07227A; <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=-117.15581&amp;materialsCitation.latitude=10.377265" title="Search Plazi for locations around (long -117.15581/lat 10.377265)">GenBank</a> 16S gene: PV579026; NHMUK ANEA 2024.2710 • 1 spec.; 10.33079203 ° N, 117.1940202° W; 4290.89 m depth; 1 Jun. 2021; H. Wiklund, R. <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=-117.19402&amp;materialsCitation.latitude=10.330792" title="Search Plazi for locations around (long -117.19402/lat 10.330792)">Drennan</a>, C. Boolukos and G. Bribiesca Contreras leg.; USNEL Box Core; specimen GUID: 71da1d0f-f4b9-4390-a8de-4c55e8351ad0; field ID NHM_08730; GenBank COI gene: PV577534; NHMUK ANEA 2024.2702 • 1 spec.; 10.33079203 ° N, 117.1940202° W; 4290.89 m depth; 1 Jun. 2021; H. Wiklund, R. <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=-117.19402&amp;materialsCitation.latitude=10.330792" title="Search Plazi for locations around (long -117.19402/lat 10.330792)">Drennan</a>, C. Boolukos and G. Bribiesca Contreras leg.; USNEL Box Core; specimen GUID: 290627ed-657b-4965-a9bd-920e8ca878ce; field ID NHM_08730B; GenBank COI gene: PV577535; 18S gene: PV579031; NHMUK ANEA 2024.2703 • 1 spec.; 10.332533 ° N, 117.187352° W; 4281 m depth; 24 Aug. 2022; H. Wiklund, C. Boolukos and E. Stewart leg.; USNEL Box Core; specimen GUID: d38da487-db2d-4274-bc96-ba7af0112e02; field ID NHM_09396_HW18; <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=-117.187355&amp;materialsCitation.latitude=10.332533" title="Search Plazi for locations around (long -117.187355/lat 10.332533)">GenBank</a> COI gene: PV577538; NHMUK ANEA 2024.2707 • 1 spec.; 10.334243 ° N, 117.185992° W; 4279 m depth; 12 Mar. 2022; H. Wiklund, C. Boolukos, E. Stewart and A. Bessell leg.; USNEL Box Core; specimen GUID: 82b4921b-0ff9-4337-9bc4-034367e808c5; field ID NHM_10276; <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=-117.18599&amp;materialsCitation.latitude=10.334243" title="Search Plazi for locations around (long -117.18599/lat 10.334243)">GenBank</a> COI gene: PV577539; NHMUK ANEA 2024.2708 • 1 spec.; 10.334296 ° N, 117.17708° W; 4282 m depth; 21 Nov. 2022; H. Wiklund, C. Boolukos, E. Stewart and A. Bessell leg.; USNEL Box Core; specimen GUID: fe6b7444-31bf-400f-9ed1-66530bb53a8c; field ID NHM_10374_ CB12; GenBank COI gene: PV577540; NHMUK ANEA 2024.2709 .</p><p>Description</p><p>MEASUREMENTS AND APPEARANCE. Moderately sized species, up to 2 mm in length for 10 chaetigers (Fig. 13A–C). Holotype NHMUK ANEA 2024.2704, posteriorly complete, 1.6 mm long and 0.25 mm at widest point for 10 chaetigers; only left lateral antenna remains attached, pygidium with cirri missing (Fig. 13A–B). Paratype NHMUK ANEA 2024.2701, live specimen translucent with 10 chaetigers (Fig. 13C), now as SEM specimen on stub, posteriorly incomplete, ~ 0.8 mm long and 0. 25 mm wide at widest point for 5 chaetigers, left lateral antenna missing (Fig. 14A). Paratype NHMUK ANEA 2024.2706, specimen with 10 chaetigers, with pygidium removed for tissue sampling for DNA analysis, rest of the body well preserved, ~ 1.3 mm long 0.25 mm wide. Other specimens in variable condition, usually posteriorly incomplete due to preservation or tissue sampling for DNA. Body somewhat dorsoventrally flattened. Fixed specimen opaque, creamy white in ethanol (Fig. 13 A–B).</p><p>PROSTOMIUM. Oval, wider than long (Fig. 13A) under light microscope; SEM shows differentiation with distinct median lobe approximating the diamond shape in postero-dorsal view (Figs 6C, 14B). Eyes absent. Prostomium bearing three short digitiform to club-shaped antennae and two palps (Fig. 14A–B). Antennae about the length of prostomium; median antenna club shaped, slightly longer than lateral antennae, and inserted on the prostomial median lobe (Fig. 14A–B); lateral antennae digitiform, inserted more anteriorly on the inferior prostomial lobe (Fig. 14A–B). Palps slightly longer than the prostomium, thick, digitiform and distally rounded, free to the base (Fig. 14A–B).</p><p>TENTACULAR SEGMENT. Achaetous, bearing two short oval tentacular cirri, ~ ½ the length of median antenna, inserted laterally (Fig. 14A–B). Pharyngeal tube extending to chaetiger 3; proventricle spanning from chaetigers 3–5 lightbulb shaped; number of muscle cell rows mostly obscured by body wall.</p><p>PARAPODIA. Long, rectangular, and uniramous. Parapodia with well-developed conical dorsal lobe and two smaller lobes, best observed in paratype NHMUK 2024.2706 (Fig. 16A–B). Internal glands in the distal part of parapodia retain Shirlastain A. Dorsal cirri always missing, SEM shows presence of cirrophores on chaetiger 1, unclear in other chaetigers. Ventral cirri short and conical, approximately half the length of the antennae, inserted medially on parapodia (Fig. 14C). Only one aciculum per parapodium confirmed, with non-emergent tip (Fig. 16C). Each parapodium with sparse bundles of ~15–20 chaetae. All chaetae compound heterogomph, falcigerous to spiniger-like (Fig. 16D–E). Shafts of falcigerous chaetae in chaetigers 1–4 denticulated with denticles arranged in irregular horizontal rows (Fig. 15B), other shafts smooth. Blades variable ranging from sturdy and thin with sparse serration to wide, strap-like, ‘floppy’ and densely serrated chaetae, best observed in mid body parapodia (Fig. 15A, D). Tips of chaetae blunt, unidentate gently curved (Fig. 15E–F) or distinctly hooked (Fig. 15G), some tips distinctly bidentate (Fig. 15C).</p><p>PYGIDIUM. Damaged; pygidial appendages missing.</p><p>Genetic data</p><p>Specimens (n = 12) assigned to A. villarae sp. nov. form a monophyletic clade (Supp. file 3: Fig. S1, Supp. file 4: Fig. S2), with low intraspecific divergence across all sequences (maximum intraspecific p-distance/K2P 0.8/0.8% for 16S and 0.5/0.5% for COI). No close matches on GenBank were returned following blastn analysis. In the combined phylogenetic analysis (Fig. 6), this species forms a polytomy with sequences identified as Anguillosyllis sp. MTA_2011 (discussed in A. finnelli genetics section) in addition to being close to Anguillosyllis finnelli sp. nov. In separate gene analyses (Supp. file 3: Fig. S1, Supp. file 4: Fig. S2), minimum interspecific p-distances/K2P of 13.4/14.8% 16S, and 17.1/19.5% COI were observed between A. villarae and A. finnelli, and 12.3/13.2% 16S and 19.3/26.6% COI between A. villarae and Anguillosyllis sp. MTA_2011. Anguillosyllis villarae differed from A. finnelli and Anguillosyllis sp. MTA_2011 by two and six mutations respectively in an alignment of nuclear 18S (1630 bp).</p><p>Remarks</p><p>The new species described here is easily distinguished from most known species, by the presence of hooked and bidentate chaetae. Currently only three known species, Anguillosyllis palpata, A. hampsoni and A. truebloodi (CCZ species), possess hooked chaetae. However, only in the new species described here, we have observed distinctly bidentate tips (Fig. 15C). Another character shared with A. palpata is the presence of well-developed dorsal lobes in parapodia. However, all known species that possess the enlarged dorsal lobe have a body with 11 chaetigers, while the new species has only 10. The prostomium of the new species cannot be meaningfully compared as no SEM investigations have been published previously, but it possesses a distinct median lobe approximating the diamond shape (Fig. 14B) at least when observed postero-dorsally.</p><p>Distribution</p><p>Eastern CCZ: NORI-D exploration area, depth ~ 4300 m.</p></div>	https://treatment.plazi.org/id/03CFF8703B65A652FDBD403EC918FB8C	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.		Plazi	Neal, Lenka;Drennan, Regan;Wiklund, Helena;Stewart, Eva C. D.;Rabone, Muriel;Dahlgren, Thomas G.;Glover, Adrian G.	Neal, Lenka, Drennan, Regan, Wiklund, Helena, Stewart, Eva C. D., Rabone, Muriel, Dahlgren, Thomas G., Glover, Adrian G. (2025): New species of Anguillosyllis Day, 1963 (Annelida, Syllidae) from polymetallic nodule exploration areas, eastern Clarion-Clipperton Zone, central Pacific Ocean. European Journal of Taxonomy 1026: 30-64, DOI: 10.5852/ejt.2025.1026.3105, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3105/13857
