taxonID	type	description	language	source
B6558E4AFFBDFF8DA030FA32C118F826.taxon	type_taxon	Type-species Aphelochaeta monilaris Hartman, 1960. Original designation by Blake (1991).	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFFBDFF8DA030FA32C118F826.taxon	diagnosis	Diagnosis (after Blake 2018) Prostomium conical to rounded; peristomium elongate with a pair of grooved dorsal tentacles arising either on or anterior to chaetiger 1. Anterior segments often expanded, sometimes much shorter than wide or high; abdominal segments sometimes beaded or moniliform in appearance; chaetae simple capillaries lacking distinct serrations using light microscopy but distinct fibrils may be visible using SEM; posterior end frequently expanded, tapering to a simple pygidial lobe.	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFFBAFF84A3BFFEE0C39AFDFC.taxon	description	Figs 2 – 6	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFFBAFF84A3BFFEE0C39AFDFC.taxon	diagnosis	Diagnosis Body widened and dorsoventrally flattened anterior part. Peristomium square to triangular, with three rings forming two distinct notches around nuchal organs with a narrow crest in between. Dorsal tentacles and first pair of branchiae arising between peristomium and chaetiger 1. Up to 44 capillaries per parapodium. Complex methylene blue pattern with peristomium nearly entirely stained, numerous latero-ventral bands anteriorly and short segmental lateral bands in midbody.	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFFBAFF84A3BFFEE0C39AFDFC.taxon	materials_examined	Material examined Syntypes IRELAND • 1 spec.; Galway, Bofin; 27 Aug. 1900; 2 – 7 m deep; NMINH _ 1908.77.33 • 1 spec.; Galway, Killary Harbour; 22 Aug. 1911; 13 m deep; NMINH _ 1908.77.32 • 1 spec.; Clew Bay; 16 Aug. 1910; 5 m deep; NMINH _ 1910.557.5 • 6 specs; Clew Bay; 26 May 1909; 7 m deep; NMINH _ 1909.151.10. Other material NORTH SEA • 1 spec.; 60.206 ° N, 4.986 ° E; 166 m deep; 23 Apr. 2014; ZMBN 95816 • 1 spec.; 60.2593 ° N, 5.13703 ° E; 248 m deep; 13 Jun. 2017; ZMBN 116564 • 1 spec.; 60.2883 ° N, 5.63512 ° E; 120 m deep; 5 Oct. 2019; ZMBN 138604 • 2 specs; 60.1221 ° N, 5.9286 ° E; 460 m deep; 29 May 2018; ZMBN 139442, ZMBN 139462 • 1 spec.; 60.44241 ° N, 4.93273 ° E; 112 m deep; 24 Jun. 2020; ZMBN 139446 • 1 spec.; 60.22675 ° N, 5.33616 ° E; 35 – 42 m deep; 9 Feb. 2006; ZMBN 173382 • 1 spec.; 59.21389 ° N, 5.77531 ° E; 168 m deep; 10 Jun. 2014; ZMBN 173394. NORWEGIAN SEA • 2 specs; 61.60182 ° N, 5.1763 ° E; 235 m deep; 8 Jan. 2018; ZMBN 138601, ZMBN 139455 • 1 spec.; 61.46669 ° N, 7.55726 ° E; 126 m deep; 18 Nov. 2012; ZMBN 173391 • 1 spec.; 61.09854 ° N, 5.10296 ° E; 241 – 254 m deep; 2 Nov. 2011; ZMBN 173390 • 1 spec.; 63.68222 ° N, 9.7835 ° E; 200 m deep; 25 Oct. 2016; ZMBN 173409. SKAGERRAK • 4 specs; 58.88556 ° N, 11.08826 ° E; 126 m deep; 1 May 2021; GNM-POLYC 15678, GNM-POLYC 15681, GNM-POLYC 15674, GNM-POLYC 15679 • 2 specs; same data as for preceding; DNA vouchers MG 865, MG 868 (no repository, specimens used for SEM) • 1 spec.; 58.9115 ° N, 10.6 ° E; 200 – 300 m deep; 17 May 2009; MG 1274.	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFFBAFF84A3BFFEE0C39AFDFC.taxon	description	Description Mostly based on five newly collected complete specimens and one complete syntype. Complete specimens from 25 to 33 mm long, 0.8 to 1 mm wide anteriorly, 0.2 to 0.4 mm wide in midbody, with 199 to 219 segments (Fig. 2). Colour in live specimens orange-red with a dark red heart body along most of anterior half, anterior pale pink to pale yellow, dorsal tentacles white, branchiae yellow, posterior end generally transparent except for gut content (Fig. 3). Colour of ethanol fixed specimens light tan, anterior chaetigers can be darkly pigmented, prostomium, peristomium and venter usually lighter, heart body rarely distinct, best visible anteriorly. Body long and slender with a distinct widened and dorsoventrally flattened anterior part, posterior segments rarely slightly expanded (Fig. 2). Anterior 35 – 38 segments 12 – 20 times as wide as long, 6 – 12 times as high as long, flat oval in cross section. Mid-body segments 3 – 5 times as wide as long and 2 – 3 times as wide as long, round to oval in cross section, venter flat. Posterior 30 segments 5 – 6 times as wide and as high as long, round to oval in cross section, sometimes dorsally expanded. A shallow groove along dorsum of mid-body segments (Fig. 4 A). A wide longitudinal ventral ridge along anterior part, developing into a groove along rest of body (Fig. 4 B). Prostomium as long as 2.5 segments, triangular, slightly dorso-ventrally flattened, wide posteriorly tapering to narrower, round apex, without rings; eyespots absent; nuchal organs as simple slit at posterolateral edge of prostomium (Fig. 5). Peristomium as long as 4 – 5 segments, square shaped; three rings present, anterior one incomplete dorsally, slightly overlapping with prostomium anteriorly in a narrow crest, middle one incomplete dorsally, overlapping posterior one to end in a V shape between tentacles over chaetiger 1, with longitudinal groove through part of the dorsal side (Fig. 5). Dorsal tentacles arising between peristomium and chaetiger 1, over chaetiger 1, rather close together (Fig. 5). First pair of branchiae arising between peristomium and chaetiger 1, lateral to tentacles, aligned with following branchiae (Fig. 5). Second pair of branchiae arising from chaetiger 1, dorsal and slightly posterior to parapodia (Fig. 5). Subsequent branchiae similarly located, branchiae or branchial scars present on most anterior segments, less frequent in following segments. Parapodia distinct mounds, higher than dorsum anteriorly forming very distinct shoulders (Figs 5, 6 A, C), progressively shifting ventrally and shrinking to a third or a fourth of the height of mid-body segments and becoming less distinct towards pygidium (Fig. 4 C). Twelve to 22 capillary chaetae per each neuro-and notopodium in anterior and midbody segments, notochaetae 1.5 – 6 times as long as neurochaetae, up to 1.5 times as long as body width, with minute fibrillation along one edge visible with SEM (Fig. 4 D – E). Five to seven simple and smooth capillary chaetae per each neuro and notopodium in posterior segments, notochaetae 1.5 – 6 times as long as neurochaetae, shorter than midbody chaetae, smooth. Pygidium with terminal anus and small, rounded to triangular ventral lobe (Fig. 3 C). Methylene blue Specimens retain a complex methylene blue pattern (Fig. 6). The peristomium stains nearly entirely, highlighting the notches it forms around the nuchal organs where the prostomium does not stain. Numerous thin ventrolateral bands stain from chaetiger 1, progressively fading into short lateral bands around the neuropodia only.	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFFBAFF84A3BFFEE0C39AFDFC.taxon	distribution	Distribution and habitats This species was first found in Norway and originally described from Ireland. It was found along the coasts of Norway and Sweden, from depths of 35 to 460 m. In Sweden, it was found in one station with soft mud and a lot of Desmophylum pertusum (Linnaeus, 1758) rubble.	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFFBAFF84A3BFFEE0C39AFDFC.taxon	description	Phylogenetic placement In the phylogeny of Grosse et al. (2025 c), Aphelochaeta mcintoshi, as Aphelochaeta sp. B, belongs to group IV (comprising members of Aphelochaeta, Kirkegaardia and Tharyx), clade A 3. It was recovered sister species to Aphelochaeta abyssorum Hansen, 1878.	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFFBAFF84A3BFFEE0C39AFDFC.taxon	discussion	Remarks A description of this species was first given based on specimens from Drøbak (Oslofjord, Norway) as Cirratulus norvegicus? (McIntosh 1911). Southern (1914) considered this as a description of a new species, although the name was preoccupied by Cirratulus norvegicus (Quatrefages, 1865), and therefore proposed a replacement name for this species, Cirratulus mcintoshi (Southern 1914) based on specimens from McIntosh and new material from Ireland. However, McIntosh did not mean to establish a new species and was only describing material he had identified what Quatrefages called Cirratulus norvegicus. Therefore even though Southern meant to only propose a replacement name he did, in fact, describe a new species and the material he examined and that is housed at the National Museum of Ireland in Dublin is considered the type series (Read & Fauchald 2024). The work in which C. mcintoshi was moved to Aphelochaeta is unknown but the combination is present in Bellan (2001) and Read & Fauchald (2024). While no original material from McIntosh’s descriptions could be found, some of the specimens from Drøbak studied herein agree well with his description and are complemented with further details and variations between populations. They also agree well with specimens studied by Southern (1914) from Ireland (Fig. 2 F) that he compared with the specimens collected by McIntosh (Southern 1914). This species is easily distinguished from other congeners in the area by its distinctive body shape with an enlarged and flattened anterior end, its methylene blue staining pattern that includes numerous ventral bands and small lateral bands (where only a few are present in Aphelochaeta marioni and none in Aphelochaeta elinorae sp. nov.) and the shape of the peristomial crest forming two circles around the nuchal organs. It mainly differs from Aphelochaeta annae sp. nov. by the shape of the prechaetiger area which is notably more fusiform in A. annae and the methylene blue staining pattern which includes numerous narrow ventral bands where A. annae shows broad stained ventral bands that cover nearly the entire length of anterior segments. Among all described species of Aphelochaeta, A. mcintoshi is most similar to A. petersenae Blake, 1996 from southern California (intertidal to shallow subtidal) with which it shares a similar staining pattern, position of dorsal tentacles and first pair of branchiae, and number and distribution of chaetae.	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFFB4FF9EA075FD76C143F99D.taxon	description	Figs 7 – 11	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFFB4FF9EA075FD76C143F99D.taxon	diagnosis	Diagnosis Anterior end usually slightly wider than midbody. Peristomium long with three rings best visible laterally. Dorsal tentacles and first pair of branchiae arising between last peristomial ring and chaetiger 1. Up to 42 capillary chaetae per parapodium. 5 – 15 strong ventral bands anteriorly with methylene blue.	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFFB4FF9EA075FD76C143F99D.taxon	materials_examined	Materiel examined Syntypes ENGLISH CHANNEL • 1 spec.; Dinard; Jul. 1880; MNHN-IA-TYPE 0953 • 1 spec.; Dinard; 11 Jul. 1881; MNHN-IA-TYPE 0959 • 1 spec.; Dinard; 19 Jun. 1882; MNHN-IA-TYPE 0957 • 1 spec.; Dinard; Aug. 1882; MNHN-IA-TYPE 0958 • 2 specs; Dinard; 16 Aug. 1984; MNHN-IA-TYPE 0955, MNHN-IA-TYPE 0960 • 1 spec.; Dinard; 2 Jul. 1889; MNHN-IA-TYPE 0956 • 1 spec.; Dinard; Jul. 1889; MNHN-IA-TYPE 0954. Other material ENGLISH CHANNEL • 2 specs; 48.71100 ° N, 3.86602 ° W; 18 m deep; 7 Sep. 2018; NHMO-IN- 10040, MG 508 (no repository, specimen used for SEM) • 2 specs; 48.71148 ° N, 3.8695 ° W; 18 m deep; 7 Sep. 2018; NHMO-IN- 10041, NHMO-IN- 10042 • 2 specs; 48.7083 ° N, 3.8662 ° W; 18 m deep; 24 Aug. 2021; NHMO-IN- 10043, MG 894 (no repository, specimen used for SEM) • 1 spec.; 48.7191 ° N, 3.8665 ° W; 20 m deep; 24 Aug. 2021; NHMO-IN- 10044 • 2 specs; 48.6829 ° N, 3.9384 ° W; 17 m deep; 24 Aug. 2021; NHMO-IN- 10045. KATTEGAT • 1 spec.; 56.84203 ° N, 11.96502 ° E; 35.2 m deep; 5 May 2020; collected with grab; GNM-POLYC 15685. NORTH SEA • 3 specs; 60.31888 ° N, 5.25528 ° E; 48 m deep; 12 Sep. 2019; collected with dredge; NTNU-VM 76397, NTNU-VM 76399, NTNU-VM 76400 • 1 spec.; 60.4085 ° N, 5.03183 ° E; 113 m deep; 10 Jan. 2019; ZMBN 138600 • 1 spec.; 60.26910 ° N, 5.11570 ° E; 98 m deep; 2 May 2006; ZMBN 173350 • 1 spec.; 60.33660 ° N, 5.19405 ° E; 20 – 63 m deep; 10 May 2014; ZMBN 173353 • 1 spec.; 60.54973 ° N, 5.22897 ° E; 37 m deep; 20 Apr. 2017; ZMBN 173360 • 1 spec.; 60.22675 ° N, 5.33616 ° E; 35 – 43 m deep; 9 Feb. 2006; ZMBN 173349 • 1 spec.; 60.95258 ° N, 4.78560 ° E; 44 m deep; 18 Jun. 2020; ZMBN 173361. NORWEGIAN SEA • 1 spec.; 61.1959 ° N, 4.81285 ° E; 65 m deep; 3 Oct. 2019; ZMBN 138602. SKAGERRAK • 1 spec.; 59.6607 ° N, 10.60637 ° E; 20 m deep; 22 May 2018; collected with dredge; NTNU-VM 76394.	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFFB4FF9EA075FD76C143F99D.taxon	description	Description Complete specimens up to 25 mm long, 2 mm wide and 190 segments (Fig. 7). Colour in ethanol light gray to light tan, prostomium, peristomium and venter often lighter than rest of body, heart-body rarely distinct. Body long and slender, anterior region usually slightly wider than midbody region, posterior region generally dorsally and laterally expanded tapering to pygidium. Anterior 30 – 35 segments up to 7 – 9 times as wide as long and 6 – 7 times as high as long, oval in cross section, flat ventrally, tapering towards peristomium. Mid-body segments 4 – 5 times as wide and as high as long, flat ventrally and round dorsally. Posterior region can be dorsally inflated, tapering towards pygidium, over the last 50 – 60 segments, segments 8 – 10 times as wide and as high as long, flat ventrally and round dorsally. A thin longitudinal dorsal groove from segment 1 – 8 along entire body (Fig. 8 B). A more distinct longitudinal ventral groove along entire body. Prostomium short, as long as half of peristomium, conical, pointed to rounded; without rings; eyespots absent; nuchal organs as simple slits on posterolateral margin (Fig. 9). Peristomium as long as 3 – 5 anterior segments; wide, trapezium-shaped, tapering towards prostomium, 3 rings of similar size, best visible laterally, middle ring overlapping anterior ring and posterior ring dorsally, ending in a V or U shape between dorsal tentacles (Fig. 9). Dorsal tentacles arising between last peristomial ring and chaetiger 1, partially to well above chaetiger 1, close together (Fig. 9). First pair of branchiae arising between last peristomial ring and chaetiger 1, close to dorsal tentacles (Fig. 9). Second pair of branchiae arising from chaetiger 1, dorsal and slightly posterior to parapodia (Fig. 9). Subsequent branchiae similarly located, branchiae or branchial scars present on most anterior segments, less frequent in following segments. Parapodia low mounds, distinct and covering most of the height of the first 10 – 20 segments (Fig. 9 A – B), forming low shoulders, progressively shrinking down to a third or a fourth of height of mid-body segments (Fig. 8 A) and becoming less distinct towards pygidium (Fig. 8 C), always placed ventrally. 15 – 21 capillary chaetae per each neuro- and notopodium in anterior segments and mid-body segments; notochaetae 1.5 – 6 times as long as neurochaetae, slightly shorter than body width, smooth (Fig. 8 F – G). 5 – 7 capillary chaetae per each neuro- and notopodium in posterior end; notochaetae 1.5 – 6 times as long as neurochaetae, shorter than midbody chaetae, smooth; neurochaetae slightly curved basally and with minute fibrillation along the concave edge (Fig. 8 H). Pygidium terminal, with a very reduced round ventral lobe (Fig. 8 C). Methylene blue Five to 15 conspicuous dark bands on venter of segments 13 – 19 to 17 – 29, depending on specimen size (Fig. 10). Pygidium of some specimens also stains. With stronger (longer) staining, peristomium and prostomium of some specimens retain a light stain and light lateroventral bands appear on all anterior segments as well as intersegmental bands in posteriormost segments.	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFFB4FF9EA075FD76C143F99D.taxon	distribution	Distribution and habitat Aphelochaeta marioni has been found along the coasts of Norway, Sweden and France (English Channel) from depths of 15 to 113 m.	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFFB4FF9EA075FD76C143F99D.taxon	description	Phylogenetic placement In the phylogeny of Grosse et al. (2025 c), Aphelochaeta marioni belongs to group IV (comprising members of Aphelochaeta, Kirkegaardia and Tharyx), clade A 3.	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFFB4FF9EA075FD76C143F99D.taxon	discussion	Remarks on the original description and type material Aphelochaeta marioni was originally described from Dinard (Saint-Joseph 1894) with little detail and rather poor illustrations (Fig. 11 D). The original description mentions that the dorsal tentacles and the first pair of branchiae arise from the first chaetiger. However, these characters can be difficult to observe and interpret, even with modern equipment and today’s understanding of annelid morphology. The second notable character detailed in this description is the fact that only capillary chaetae are present. Notochaetae are straight, thin, and as long as the body width. Neurochaetae are anteriorly similar to notochaetae but progressively become shorter and slightly curved. Although they were believed lost for a long time (Blake 1996), a type series is available at the Natural History Museum in Paris (Solís-Weiss et al. 2004). These specimens are small and mounted on slide (Fig. 11 A – C). They are unlikely to be fully representative of the material originally studied by Saint-Joseph as his descriptions mention specimens from 35 to 70 mm (Saint-Joseph 1894). Moreover, the preservation quality is very variable as some specimens are still transparent while some others have turned completely black. Nevertheless, some information could be gathered from this material. Enlarged anterior and posterior parts are visible in some specimens. Segments in midbody are sometimes elongated but never longer than wide or beaded. The prostomium is generally short and varies from pointed to more rounded. The peristomium is generally three to four times as long as the prostomium, with none to three rings visible. The position of the dorsal tentacles and first pair of branchiae could not be observed. Around ten capillaries are visible in the notopodia and at least five in neuropodia. Details of the capillaries could not be observed, except for some of the shorter ones in neuropodia that are often thicker at the base. Overall, the material examined in this study agrees (or perhaps simply does not disagree) with the scarce information present in the original description and the type material. As this is the only species of Aphelochaeta collected in the vicinity of Dinard (Roscoff), we propose that this species is Aphelochaeta marioni. Aphelochaeta marioni is best distinguished from other species of Aphelochaeta in the area by its methylene blue staining pattern which reveals only ventral bands, while that of Aphelochaeta mcintoshi and A. annae sp. nov. are more complex and A. elinorae sp. nov. has no pattern. It is distinguished from Tharyx maryae by the shape of the peristomium, of which the second ring overlaps dorsally the third ring and ends between the tentacles, by the position of the dorsal tentacles on the posterior margin of the peristomium and by the presence of a dorsal groove.	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFFAEFF98A00EF9D7C0FEFAB0.taxon	description	urn: lsid: zoobank. org: act: 890 EBCF 0 - 2 B 8 E- 4 B 11 - BE 95 - DB 7 C 80 B 9 BB 14 Figs 12 – 16	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFFAEFF98A00EF9D7C0FEFAB0.taxon	diagnosis	Diagnosis Fusiform anterior end; short triangular prechaetiger area, three peristomial rings, posterior one incomplete bearing dorsal tentacles and branchiae. Dorsal tentacles arising from third peristomial ring, first pair of branchiae arising from posterior margin of peristomium. Up to 55 chaetae per parapodium in anterior end. Posterior of peristomium, anterior and posterior parapodia stain strongly with methylene blue, few broad and long anterior ventral bands.	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFFAEFF98A00EF9D7C0FEFAB0.taxon	etymology	Etymology This species is named after Anne Elliot, one of the main characters of the novel Persuasion by Jane Austen.	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFFAEFF98A00EF9D7C0FEFAB0.taxon	materials_examined	Material examined Holotype NORTH SEA • Nordfjord; 61.90826 ° N, 5.54251 ° E; 575 m deep; 30 Mar. 2020; ZMBN 139441. Paratypes NORWEGIAN SEA • 2 specs; same data as for holotype; ZMBN 139461, MG 696 • 2 specs; 59.998367 ° N, 5.876067 ° E; 609 m deep; 9 Oct. 2020; ZMBN 138603, ZMBN 139457 • 3 specs; 61.12629 ° N, 5.17834 ° E; 573 – 621 m deep; 14 Jul. 2015; ZMBN 173454 to ZMBN 173456 • 1 spec.; 61.14478 ° N, 7.19684 ° E; 100 – 400 m deep; 18 Nov. 2012; ZMBN 173452 • 1 spec.; 65.50056 ° N, 6.26848 ° E; 396 m deep; 23 Jun. 2013; ZMBN 173462 • 1 spec.; 61.38362 ° N, 2.12090 ° E; 280 m deep; 29 May 2011; ZMBN 173489 • 1 spec.; 66.94977 ° N, 12.40812 ° E; 280 m deep; 22 May 2011; ZMBN 173471 • 1 spec.; 61.04 ° N, 3.6 ° E; 400 m deep; 30 May 2019; MG 1188 (no repository, specimens used for SEM). NORTH SEA • 1 spec.; 60.13 ° N, 3.55 ° E; 400 m deep; 30 May 2019; MG 1185 (no repository, specimens used for SEM) • 1 spec.; 60.79 ° N, 3.41 ° E; 300 m deep; 22 May 2019; MG 1190 (no repository, specimens used for SEM) • 1 spec.; 60.26883 ° N, 5.14800 ° E; 240 m deep; 14 Apr. 2005; MG 1202 (no repository, specimens used for SEM) • 1 spec.; 60.13656 ° N, 4.80873 ° E; 327 m deep; 27 Apr. 2017; ZMBN 173481.	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFFAEFF98A00EF9D7C0FEFAB0.taxon	description	Description Holotype complete, 25 mm long (complete paratypes: 15 – 28 mm), 0.5 mm wide (complete paratypes: 0.5 – 1 mm), 205 segments (complete paratypes: 145 – 205 segments) (Fig. 12). Colour of ethanol preserved specimens light tan to light brown, prechaetiger area and venter usually lighter than dorsum; dark heart body usually visible dorsally along anterior half, a checkered pattern with dark outline visible dorsally along nearly entire body of mature females due to presence of large eggs in body cavity (Fig. 12). Body long and slender, distinct short fusiform anterior region slightly widened and dorsoventrally flattened, long cylindrical mid-body region and a short expanded posterior end, tapering towards pygidium. Anterior 30 segments 5 – 6 times as wide as long and 3 – 4 times as high as long, oval in cross section. Mid-body segments 2 – 2.5 times as wide as long, round in cross section. Posterior 30 segments up to eight times as wide as long and up to 10 times as high as long, dorsally expanded, venter flat. A thin longitudinal dorsal groove along posterior part. A wide longitudinal ventral ridge formed by segmental pads along midbody and posterior segments, sometimes hidden in a groove due to the contraction of ventral pads under parapodia in some specimens. Prostomium as long as half of peristomium, triangular, broad, sides and dorsum rounded; nuchal organs as long slits on posterolateral margins (Fig. 13). Peristomium as long as 3 – 4 segments, slightly longer than wide and high, three rings best visible laterally, middle one twice longer than flanking ones with a short round posterior extension, posterior one fused with middle one ventrally and incomplete dorsally; dorsal crest broad and well developed, overlapping half of prostomium anteriorly (Fig. 13). Dorsal tentacles arising from third peristomial ring, well separated (Fig. 13). First pair of branchiae arising from posterior margin of peristomium, aligned with tentacles and following branchiae (Fig. 13). Second pair of branchiae arising from chaetiger 1, dorsolateral to notopodia (Fig. 13). Subsequent branchiae similarly located, present in most anterior segments, less frequent in following segments. Parapodia as low mounds in anterior segments (Fig. 13), progressively shifting to a lateral position as the dorsum gets rounder and becoming simple low and small ridges in midbody (Fig. 12). Chaetae all capillary, short, smooth, neurochaetae generally enlarged and slightly flattened basally, becoming thinner distally, shorter than notochaetae; 12 – 25 chaetae per neuropodium and 15 – 20 chaetae per notopodium in anterior segments, arranged in two vertical rows, decreasing to 2 – 3 chaetae per neuropodium and notopodium in posterior segments (Fig. 14). Pygidium with terminal anus and small triangular ventral lobe (Fig. 15 E – F). Methylene blue A complex, distinct pattern (Fig. 15). Posterior half of peristomium stain with dense concentration of dark spots dorsally, rest of peristomium stains lightly except the part that overlaps prostomium. Long and wide lateroventral bands completely colour the venter and parapodia from segments 1 to 14 – 15. Thin ventral bands can remain long after differentiation (Fig. 15 D).	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFFAEFF98A00EF9D7C0FEFAB0.taxon	distribution	Distribution and habitats This species has been found along the coast of Norway, from depths of 226 to 621 m (Fig. 16).	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFFAEFF98A00EF9D7C0FEFAB0.taxon	description	Phylogenetic placement In the phylogeny of Grosse et al. (2025 c), Aphelochaeta annae sp. nov., as A. spD belongs to group IV (comprising members of Aphelochaeta, Kirkegaardia and Tharyx), clade A 1.	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFFAEFF98A00EF9D7C0FEFAB0.taxon	discussion	Remarks Aphelochaeta annae sp. nov. can be distinguished from other similar species in the area by its fusiform anterior end with a pointed prostomium and by its methylene blue staining pattern which reveals broad ventral bands on anterior segments colouring most of the venter in dark blue where ventral bands in other species, when present, are always narrow and well separated. Similar staining patterns to that of A. annae have been observed in Aphelochaeta tigrina Blake, 1996 from California (USA) and Aphelochaeta zebra Dean & Blake, 2009 from the Pacific coast of Costa Rica, from which A. annae differs in particular in the absence of dorsal crest or projection.	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFFA8FF95A003FAB2C1ACFBE7.taxon	description	urn: lsid: zoobank. org: act: AA 4 B 6 EC 1 - 768 C- 453 D-A 65 E-A 092 E 7 A 93 C 4 E Figs 17 – 21	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFFA8FF95A003FAB2C1ACFBE7.taxon	diagnosis	Diagnosis Bulbous anterior end with three peristomial ring covered by large dorsal crest. Dorsal tentacles and first pair of branchiae arising between peristomium and chaetiger 1. Numerous capillary chaetae with up to 50 notochaetae per anterior parapodium giving the worm a fluffy appearance. No methylene blue staining pattern.	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFFA8FF95A003FAB2C1ACFBE7.taxon	etymology	Etymology Aphelochaetae elinorae sp. nov. is named after Elinor Dashwood, one of the main characters of the novel Sense and Sensibility by Jane Austen.	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFFA8FF95A003FAB2C1ACFBE7.taxon	materials_examined	Material examined Holotype NORWEGIAN SEA • Eikefjorden; 61.58232 ° N, 5.35332 ° E; 52 m deep; 19 Aug. 2020; ZMBN 139436. Paratypes NORTH ATLANTIC • 1 spec.; 63.09146 ° N, 24.54128 ° E; 234 m deep; 5 May 2018; SMF 33145. NORTH SEA • 1 spec.; 60.2 ° N, 5.041 ° E; 60 m deep; 23 Apr. 2014; ZMBN 95780 • 1 spec.; 59.31002 ° N, 6.15833 ° E; 321 m deep; 12 Jul. 2019; ZMBN 138598 • 1 spec.; 60.19905 ° N, 6.09565 ° E; 120 m deep; 15 May 2018; ZMBN 138599 • 1 spec.; 60.46928 ° N, 5.22811 ° E; 68 m deep; 9 Jul. 2020; ZMBN 139434 • 1 spec.; 60.47278 ° N, 5.23398 ° E; 155 m deep; 9 Jul. 2020; ZMBN 139435 • 1 spec.; 60.18085 ° N, 5.9594 ° E; 130 m deep; 27 May 2020; ZMBN 139437 • 1 spec.; 59.7267 ° N, 5.7851 ° E; 228 m deep; 13 Aug. 2020; ZMBN 139443 • 1 spec.; 60.44241 ° N, 4.93273 ° E; 112 m deep; 24 Jun. 2020; ZMBN 139466 • 2 specs; 60.19905 ° N, 4.93273 ° E; 120 m deep; 15 May 2018; MG 692, MG 693 (no repository, specimens used for SEM) • 1 spec.; 60.17536 ° N, 5.96353 ° E; 182 m deep; 27 May 2020; MG 694 (no repository, specimens used for SEM) • 1 spec.; 60.21465 ° N, 5.34720 ° E; 25 – 47 m deep; 28 Jun. 2017; ZMBN 173500 • 1 spec.; 60.26910 ° N, 5.11570 ° E; 98 m deep; 2 May 2006; ZMBN 173498 • 1 spec.; 60.22675 ° N, 5.33616 ° E; 35 – 42 m deep; 9 Feb. 2006; ZMBN 173497. NORWEGIAN SEA • 1 spec.; 63.703 ° N, 9.417 ° E; 60 m deep; 10 Feb. 2014; ZMBN 68704 • 1 spec.; 60.284 ° N, 5.201 ° E; ZMBN 95880 • 1 spec.; 61.58503 ° N, 5.34268 ° E; 42 m deep; 19 Aug. 2020; ZMBN 139463 • 1 spec.; 63.68222 ° N, 9.7835 ° E; 200 m deep; 25 Oct. 2016; ZMBN 173522. SKAGERRAK • 1 spec.; 58.8 ° N, 11.1 ° E; 1 May 2021; GNM-POLYC 15677 • 1 spec.; 58.8856 ° N, 11.08826 ° E; 126 m deep; 6 Jun. 2021; MG 858 (no repository, specimens used for SEM).	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFFA8FF95A003FAB2C1ACFBE7.taxon	description	Description Holotype complete, in six fragments (Fig. 17), approximately 80 mm long (paratypes up to 30 mm long, but all incomplete), 15 mm wide anteriorly (paratypes: 0.6 – 2 mm), 1 mm wide in midbody (paratypes: 0.4 – 1.5 mm), 174 segments. Colour of live specimens pink to red, head cream to yellow with distinct blood vessels (Fig. 18). Colour of ethanol fixed specimens white to light tan, rarely yellow, venter usually lighter than rest of body. Anterior region enlarged and slightly dorsoventrally flattened, tapering softly towards peristomium and midbody, with short, crowded segments; mid-body region elongated, nearly round in cross section, segments always wider and higher than long; short posterior region slightly enlarged with very short segments. Anterior 31 (30 – 50) segments 10 – 20 times as wide and 7 times as high as long, oval in cross section, venter flat, dorsum slightly rounded. Mid-body segments 4 – 5 times as wide and as high as long, round in cross section, venter flat. Last 30 – 40 segments up to 12 times as wide and 8 times as high as long, oval in cross section, venter flat, dorsum rounded. A thin longitudinal dorsal groove from segment 15 and along entire body, sometimes indistinct. Distinct longitudinal ventral groove along entire body separating two wide, flat ridges marked by ventral groove and parapodia in midbody (Fig. 19 A – B). Prostomium as long as a third to a half of peristomium, conical, rounded, without rings; eyespots absent; nuchal organs as oval pits, on posterolateral margins of prostomium (Fig. 20). Peristomium as long as 4 – 5 segments, square to trapezium-shaped, 3 rings best visible laterally, large dorsal crest covering entire peristomium, overlapping prostomium anteriorly, overlapping chaetiger 1 posteriorly (Fig. 20). Dorsal tentacles arising between peristomium and chaetiger 1, over chaetiger 1, well separated (Fig. 20). First pair of branchiae arising between peristomium and chaetiger 1, lateral and slightly anterior to dorsal tentacles, usually not aligned with following branchiae (Fig. 20). Second pair of branchiae arising from chaetiger 1, dorsal and slightly posterior to parapodia (Fig. 20). Subsequent branchiae similarly located, branchiae or branchial scars present on most anterior segments, less frequent in following segments. Parapodia low mounds, making slight shoulders lower than dorsum in anterior segments (Fig. 20) and shifting to a ventral position around middle of anterior region (Fig. 19 A), staying distinct along entire body. Chaetae all capillaries, short, neurochaetae and notochaetae of similar length in anterior region, notochaetae longer than neurochaetae in midbody; chaetae mostly smooth, some neurochaetae with finely serrated edge or protruding fibrils from midbody visible with SEM (Fig. 19 F – H); up to 50 chaetae in neuropodium and notopodium in anterior segments (Fig. 19 D – H), extending laterally and giving a fluffy appearance to the specimens (Fig. 20 B), decreasing to about 20 chaetae per neuropodium and notopodium in mid-body segments. Methylene blue No pattern.	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFFA8FF95A003FAB2C1ACFBE7.taxon	distribution	Distribution and habitats Aphelochaeta elinorae sp. nov. has been found along the coasts of Norway and Sweden as well as offshore Iceland from depths of 35 to 366 m (Fig. 21).	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFFA8FF95A003FAB2C1ACFBE7.taxon	description	Phylogenetic placement In the phylogeny of Grosse et al. (2025 c), Aphelochaeta elinorae sp. nov., as Aphelochaeta. spI, belongs to group IV (comprising members of Aphelochaeta, Kirkegaardia and Tharyx), clade A 2.	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFFA8FF95A003FAB2C1ACFBE7.taxon	discussion	Remarks Aphelochaeta elinorae sp. nov. can be distinguished from other species in the area by its bulbous head, the numerous capillary chaetae present in anterior segments (two to four times more than in other species) giving it a fluffy appearance and the lack of a methylene blue staining pattern. Among all described species of Aphelochaeta, A. elinorae is most similar to Aphelochaeta bulbata Doner & Blake, 2009 from California (USA) in the shape of the peristomium from which it mainly differs in the larger number of chaetae and the lack of methylene blue staining pattern.	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFFA2FF92A035FEE1C0B0FC05.taxon	type_taxon	Type species Monticellina heterochaeta Laubier, 1961. Original designation by Blake (2016).	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFFA2FF92A035FEE1C0B0FC05.taxon	diagnosis	Diagnosis (after Blake 2016) Bitentaculate cirratulids with distinct body regions and all setae distally pointed. Pre-chaetigerous area typically elongate, cylindrical, with short, blunt prostomium and long peristomium with zero to many weakly developed annulations; dorsal tentacles arising on posterior margin of peristomium, anterior to chaetiger 1. Thoracic notopodia often shifted dorsally, elevated, producing distinct dorsal groove along thoracic region; other species with thoracic parapodia more lateral, leaving broad elevated dorsum; parapodia of middle and posterior region lateral. Middle body segments longer than wide, frequently bead-like; posterior segments wider than long, somewhat crowded, with posterior most segments usually expanded or enlarged. chaetae include simple capillaries with fibrils observed under SEM and denticulated capillaries with distinct denticles present along one edge of chaetae; denticles visible at 400 – 1000 ×; blades usually basally expanded.	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFFA2FF91A05DFC44C0C8FAD8.taxon	description	Figs 22 – 23	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFFA2FF91A05DFC44C0C8FAD8.taxon	materials_examined	Material examined Holotype SKAGERRAK • 58.8 ° N, 10.7 ° E; 295 m deep; 27 Jun. 1933; UUZM POLYCHAETA type # 193 - a. Paratype SKAGERRAK • 1 spec.; same data as for holotype; UUZM POLYCHAETA type # 193 - b. Other material NORTH SEA • 1 spec.; 59.998367 ° N, 5.876067 ° E, 609 m deep; 9 Jan. 2020; ZMBN 138607 • 1 spec.; 60.15192 ° N, 5.0991 ° E; 616 m deep; 26 Apr. 2017; ZMBN 173990. NORWEGIAN SEA • 2 specs; 61.05009 ° N, 5.40054 ° E; 1236 m deep; 3 May 2017; ZMBN 144622, ZMBN 173974 • 1 spec.; 61.14350 ° N, 5.82935 ° E; 1259 m deep; 4 May 2017; ZMBN 144584 • 1 spec.; 61.1553 ° N, 7.26546 ° E; 882 m deep; 4 May 2017; ZMBN 117832 • 1 spec.; 61.1872 ° N, 6.58259 ° E; 880 m deep; 5 May 2017; ZMBN 117880 • 4 specs; Norway; MG 1085 to MG 1088 (no repository, specimens used for SEM) • 2 specs; 61.04687 ° N, 5.42164 ° E; 1236 m deep; 3 May 2017; ZMBN 173975, ZMBN 173976 • 3 specs; 61.18718 ° N, 6.58259 ° E; 880 m deep; 5 May 2017; ZMBN 173978 to 173980 • 1 spec.; 64.280478 ° N, 8.409652 ° E; 357 m deep; 21 Apr 2020; ZMBN 173983 • 1 spec.; 59.86505 ° N, 5.66967 ° E; 490 – 499 m deep; 23 Sep. 2008; collected by sledge; ZMBN 173973.	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFFA2FF91A05DFC44C0C8FAD8.taxon	diagnosis	Diagnosis Thin, elongate body, often curled, middle segments often darkly coloured. Three peristomial rings; dorsal tentacles arising from posterior margin perostomium; first pair of branchiae arising from chaetiger 1. Posterior chaetae with widened concave base and distinct serrated edge.	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFFA2FF91A05DFC44C0C8FAD8.taxon	description	Description Description based on newly collected material, not on type material. Colour of ethanol fixed specimens light tan to dark purple or brown (Fig. 22). Body thin and elongate, often curled and convoluted. First 8 – 12 segments forming a distinct anterior region, where segments are more continuous and slightly dorsoventrally flattened. Segments twice as high as long, 2.5 times as wide as long. Mid-body segments often beaded, slightly elongated in the posterior part. A distinct posterior region of approximately 10 – 21 segments progressively shortening and tapering towards pygidium. Dorsal groove or ridge absent. Ventral groove or ridge absent. Prostomium short, at most as long as half of peristomium; nuchal organs as simple slits on posterolateral margins; eyes absent (Fig. 23 A – B). Peristomium short, as long as two to three segments, rather rounded with 3 rings best visible laterally. Dorsal tentacles arising from posterior margin of peristomium (Fig. 23 A – B). first pair of branchiae arising from chaetiger 1 (Fig. 23 A – B). Second pair of branchiae arising from chaetiger 2, dorsal and slightly posterior to parapodia. Parapodia sometimes forming low shoulders anteriorly (Fig. 22 A), becoming inconspicuous ridges in midbody and posterior segments. Parapodia are situated in the middle of the segment throughout most of the body, and progressively shift towards the posterior of the segments towards the end of the body. Chaetae smooth and serrated capillaries. In anterior segments, up to 10 – 12 chaetae per neuropodium and 15 – 17 chaetae per notopodium, decreasing in posterior segments, smooth. Serrated chaetae developing progressively after expanded anterior region; base of the blade widened, tapering to a fine capillary after a short, finely serrated concave edge (Fig. 23 C – E). Pygidium with 5 – 6 small dorsal lobes and short rounded ventral lobe. Methylene blue Prostomium usually retains a dark stain except around nuchal organs. The first and third peristomial rings retain a dark stain in all specimens, the second peristomial ring only retain some stain in some specimens. Some staining can be retained ventrally as lateral or and, more rarely, ventral bands of dots or around parapodia for a few anterior segments.	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFFA2FF91A05DFC44C0C8FAD8.taxon	distribution	Distribution and habitat The material examined here has been collected along the coasts of Norway from 357 to 1259 m deep. The type locality is in the Skagerrak at a depth of 295 m. Phylogenetic placement In the phylogeny of Grosse et al. (2025 c), Kirkegaardia serrata belongs to group IV (comprising members of Aphelochaeta, Kirkegaardia and Tharyx), clade K 2.	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFFA2FF91A05DFC44C0C8FAD8.taxon	discussion	Remarks The material examined agrees well with the original description, in particular with regards to the chaetae illustrated by Eliason (1962). Kirkegaardia serrata is so far the only species of Kirkegaardia we have recorded in Norway. Other species of Kirkegaardia recorded in Europe include K. heterochaeta (Laubier, 1961), K. marypetersenae Lezzi, Çinar & Giangrande, 2016, K. dorsobranchialis (Kirkegaard, 1959), K. sp A (Blake 2016) and K. setosa (Dean & Blake, 2009). Kirkegaardia heterochaeta and K. marypetersenae were described from the Mediterranean Sea (France and Italy, respectively) and K. dorsobranchialis was described from Angola. Kirkegaardia serrata can be distinguished from the other species by the serration of its chaetae with dense, straight and pointed teeth, whereas the theth on the chaetae of K. dorsobranchialis are rounded and the ones on the chaetae of K. heterochaeta are distinctly pointing downwards (Lezzi et al. 2016). Kirkegaardia sp. A has been found in the Mediterranean coast of France and in the eastern Mediterranean but more specimens are needed to understand this species. Kirkegaardia setosa was described from the Pacific coast of Costa Rica and recently reported from the Mediterranean Sea (Borghese et al. 2023), although the large geographic distance to the type locality may indicate that it is in fact a different, potentially new species.	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFFA1FFAEA3FEFA6CC043FEC2.taxon	type_taxon	Type species Tharyx acutus Webster & Benedict, 1887.	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFFA1FFAEA3FEFA6CC043FEC2.taxon	diagnosis	Diagnosis (after Blake 2018) Prostomium conical; peristomium elongate, with pair of grooved dorsal tentacles arising on posterior margin; first pair of branchiae typically arising immediately posterior to dorsal tentacles either on posterior margin of peristomium or on chaetiger 1; abdominal segments sometimes bead-like. Noto-and neurochaetae arising close to one another, not widely separated. Chaetae include simple capillaries in anterior and middle chaetigers, acicular spines present in posterior chaetigers either in both noto-and neuropodia or only in neuropodia. Long, natatory-like chaetae present or absent. Spines typically short, curved, sometimes geniculate or sickle-shaped, narrowing to rounded irregularly notched or sub-bidentate tip; tips with pair of stunted or rounded knobs but not with two distinct teeth. Capillaries may accompany posterior spines or are absent, not alternating with spines when present. Pygidium with terminal anus and small ventral lobe or disk. Several species with black pigment markings on posterior lateral margin of peristomium.	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFF9EFFADA042FE84C0A7FE73.taxon	description	Fig. 24	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFF9EFFADA042FE84C0A7FE73.taxon	diagnosis	Diagnosis Body elongate with laterally extended anterior region and expanded posterior region; peristomium with three rings, dark pigments sometimes present laterally on the third ring; dorsal tentacles arising from third peristomial ring, first pair of branchiae arising from posterior margin of peristomium. Blunt or knobby spines may be present in posteriormost segments. Ventral bands on segments 7 – 22 and small lateral bands up to segment 22 with methylene blue.	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFF9EFFADA042FE84C0A7FE73.taxon	materials_examined	Material examined Holotype KATTEGAT • 57.11501 ° N, 12.22611 ° E; 0.3 – 1.7 m deep; 3 Aug. 2012; leg. P. Göransson; SMNH 8754. Paratypes KATTEGAT • 4 specs; same data as for holotype; SMNH 8755. Other material KATTEGAT • 1 spec.; 57.78723 ° N, 11.6903 ° E; 12.8 m deep; 11 May 2020; collected by grab; GNM-POLYC 15680 • 2 specs; 56.608683 ° N, 12.6708018 ° E; 19.8 m deep; 7 May 2020; collected by grab; GNM-POLYC 15687, GNM-POLYC 15683 • 3 specs; same data as for preceding; DNA vouchers: MG 719, MG 723, MG 724 (no repository, specimens used for SEM) • 9 specs; 56.347502 ° N, 12.669992 ° E; 18 m deep; collected by grab; GNM-POLYC 15684, GNM-POLYC 15686, GNM-POLYC 15688 to GNM-POLYC 15694. NORTH SEA • 2 specs; 60.39591 ° N, 5.32489 ° E; 6 m deep; 10 Sep. 2018; collected by grab; NTNU-VM 76395, NTNU-VM 76396 • 1 spec.; 58.12533 ° N, 7.97237 ° E; 3 m deep; 23 Aug. 2019; ZMBN 139454. NORWEGIAN SEA • 1 spec.; 63.44401 ° N, 10.41591 ° E; deep 10 m; 7 Sep. 2018; NTNU-VM 82837 • 2 specs; 63.44123 ° N, 10.50564 ° E; 5 m deep; collected by grab; NTNU-VM 76391, NTNU-VM 76393 • 3 specs; 63.44346 ° N, 10.40821 ° E; 11 m deep; collected by dredge; NTNU-VM 76415, NTNU-VM 76416, NTNU-VM 84515 • 1 spec.; 63.43234 ° N, 10.37914 ° E; 4 m deep; 5 Sep. 2018; NTNU-VM 85417 • 1 spec.; 63.43234 ° N, 10.37914 ° N; 4 m deep; 5 Sep. 2018; NTNU-VM 76417.	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFF9EFFADA042FE84C0A7FE73.taxon	description	Description Description based on newly collected material, not on type material. Complete specimens from 8.5 to 10.5 mm long, 0.3 to 0.4 mm wide and 80 to 134 segments. Colour of ethanol fixed specimens white. Small, rounded, elongated worm without any distinct enlargement. Anterior 11 – 16 segments 3 – 4 times as wide and as high as long, oval to round in cross section. Mid-body segments 1 – 2 times as wide and as high as long, round in cross section, sometimes beaded. Posterior 15 segments 6 – 10 times as wide and as high as long, dorsum rounded, venter flat. Dorsal groove or ridge absent. A distinct longitudinal ventral ridge along entire body. Prostomium as long as a third to half of peristomium, triangular, tip rounded, weakly biannulate ventrally and rounded dorsally; eyespots absent; nuchal organs simple slits at posterolateral margins (Fig. 24 A – B). Peristomium short, as long as 2 – 4 segments, rounded, slightly higher than long, 2 – 3 weak rings, best visible laterally, a weak dorsal crest slightly overlapping prostomium anteriorly and ending between tentacles posteriorly (Fig. 24 A – B). Dorsal tentacles arising from posterior margin of peristomium. First pair of branchiae arising between peristomium and chaetiger 1, posterior to tentacles, above chaetiger 1 (Fig. 24 A – B). Second pair of branchiae arising from chaetiger 1, dorsal and slightly posterior to parapodia (Fig. 24 A – B). Subsequent branchiae similarly located, branchiae or branchial scars present on most anterior segments, mostly absent in following segments. Parapodia, low mounds, forming slight shoulders anteriorly, becoming indistinct afterwards, always arising ventrally. 10 – 16 capillary chaetae per neuropodium 10 – 12 per notopodium along most of the body, decreasing in posterior segments, arranged on two rows, chaetae on anterior row twice as long as chaetae on posterior one, neurochaetae as long as notochaetae anteriorly, smooth. Modified chaetae (spines) not observed in examined material but present in type material on the last five chaetigers. Pygidium with terminal anus, dorsoventrally flattened, with small round ventral lobe. Methylene blue Ventral bands appear on segments 7 to 12. In addition some more or less dense dots appear on anterior parts of parapodia until about segment 22.	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFF9EFFADA042FE84C0A7FE73.taxon	distribution	Distribution and habitats The material examined here has been found along the coasts of Norway and Sweden, from depths of 3 to 18 m. In Norwegian harbours and marinas, it co-occurs with Tharyx robustus, and both species were originally described from the same sample at the type locality near Varberg in Sweden.	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFF9EFFADA042FE84C0A7FE73.taxon	description	Phylogenetic placement In the phylogeny of Grosse et al. (2025 c), Tharyx maryae belongs to group IV (comprising members of Aphelochaeta, Kirkegaardia and Tharyx), clade A 1.	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFF9EFFADA042FE84C0A7FE73.taxon	discussion	Remarks As the original material was described in detail, only the newly collected material is described here. This species was identified as Tharyx maryae in Grosse et al. (2025 c), but no description of the material sequenced and examined was given. The material examined generally agrees well with the original description except on three points. The first difference concerns the presence of pigmentation on the peristomium of the type specimens, which are absent in the material examined here. However, Blake & Göransson (2015) state that this pigmentation is “ faded or not apparent ” on some specimens. The second difference concerns the number of peristomial rings as only two are described in the original description, but three are illustrated. In our material, two to three rings can be observed depending on the condition of the specimen. The third difference concerns the chaetae. Indeed, no spines were observed in the material examined here, while some neurospines were present in the five posteriormost segments of the holotype. These spines were observed only in the very last segments of a single specimen, slightly larger than the specimens examined here. As some of the specimens examined here were collected relatively close to the type locality, and in similar environments to that of the type specimens, we do not consider the small differences observed between our material and the original description enough to consider our material as a different species. This species is most similar to Aphelochaeta marioni, having a similar body shape and the same number of peristomial rings. They can be differentiated by the shape of the peristomial ring, the position of the dorsal tentacles and the first pair of branchiae and the presence of a dorsal groove in Aphelochaeta marioni. In Aphelochaeta marioni, the second peristomial ring extends dorsally over the third and between the dorsal tentacles. In Tharyx maryae, a dorsal crest is present over all rings. In Apehlochaeta marioni, the dorsal tentacles arise from the posterior margin of the peristomium, while they arise from the third peristomial ring in Tharyx maryae.	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFF9DFFABA079FDF5C060FA24.taxon	description	Fig. 25	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFF9DFFABA079FDF5C060FA24.taxon	diagnosis	Diagnosis Body usually stout with short segments, often dorsso-ventrally flattened at least in anterior and / or posterior regions. Three peristomial rings covered by narrow dorsal crest; dorsal tentacles and first branchiae arising from posterior margin of peristomium. Transition chaetae from capillaries to spines are serrated spines. No methylene blue pattern.	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFF9DFFABA079FDF5C060FA24.taxon	materials_examined	Material examined Holotype KATTEGAT • 57.11501 ° N, 12.22611 ° E; 0.3 – 1.7 m deep; 3 Aug. 2012; leg. P. Göransson; SMNH 8756. Paratypes KATTEGAT • 6 specs; same data as for holotype; SMNH 8757. Other material KATTEGAT • 1 spec.; 57.96808 ° N, 11.52028 ° E; 16.5 m deep; 29 May 2022; collected by grab; GNM-POLYC 15682. NORWEGIAN SEA • 1 spec.; 63.439001 ° N, 10.50548 ° E; 3 m deep; 6 Sep. 2018; collected by grab; NTNU-VM 76387 • 2 specs; 63.43979 ° N, 10.39854 ° E; 4 m deep; 5 Sep. 2018; collected by grab; NTNU-VM 76388, NTNU-VM 76389 • 1 spec.; 63.43781 ° N, 10.50624 ° E; 4 m deep; 4 Sep. 2018; NTNU-VM 76418 • 4 specs; 63.43234 ° N, 10.37914 ° E; 4 m deep; 5 Sep. 2018; NTNU-VM 76419, NTNU-VM 76420, NTNU-VM 85413, NTNU-VM 85414.	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFF9DFFABA079FDF5C060FA24.taxon	description	Description Description based on the new material, not on the type material. One complete specimen 4.5 mm long, 0.2 – 0.3 mm wide, 72 segments. Colour of ethanol fixed specimens white to light tan. Spindle shaped, oval to flat in cross section, without any conspicuous enlargements. Anterior 15 – 20 segments 3 – 4 times as wide and as high as long, of approximately the same length as midbody segments up to 2 – 3 times shorter. Mid-body segments 3 – 4 times as wide and as high as long, sometimes with deep grooves between them dorsally. Posterior 18 – 24 segments dorsally slightly expanded, tapering towards pygidium. Dorsal groove or ridge absent. A longitudinal ventral ridge as a series of segmental bumps along entire body, sometimes appearing inside a groove as specimens fold longitudinally. Prostomium as long as half of peristomium, triangular, without rings; nuchal organs as simple slits on postero-lateral margins (Fig. 25 B – C). Peristomium as long as 3 – 4 segments, venter flat, dorsum rounded, 3 rings, sometimes indistinct or only two visible, narrow dorsal crest slightly overlapping prostomium anteriorly (Fig. 25 B – C). Dorsal tentacles arising from posterior margin of peristomium, close together (Fig. 25 B – C). First pair of branchiae arising from posterior margin of peristomium, just behind and slightly lateral to tentacles (Fig. 25 B – C). Second pair of branchiae arising from chaetiger 1, dorsal and slightly posterior to parapodia (Fig. 25 B – C). Subsequent branchiae similarly placed, branchiae or branchial scars present on nearly all segments along anterior half of body, less frequent afterwards. Parapodia low mounds, distinct but barely forming shoulders anteriorly, less distinct afterwards, always placed ventrally. Chaetae capillaries and spines. 8 – 10 capillaries per neuro and notopodium anteriorly, short, with thin fibrils visible with SEM. Spines with serrated edge, difficult to observe in light microscopy, and blunt tip or thinning to a capillary tip (Fig. 25 D). Spines with knob-like tip not observed. Pygidium with terminal anus and small, rounded ventral lobe. Methylene blue No pattern.	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFF9DFFABA079FDF5C060FA24.taxon	distribution	Distribution and habitats The material examined here was found along the coasts of Norway and Sweden, from depths of 3 to 16.5 m. In Norwegian harbours and marinas, it co-occurs with Tharyx maryae, and both species were originally described from the same sample from the type locality near Varberg in Sweden.	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFF9DFFABA079FDF5C060FA24.taxon	description	Phylogenetic placement In the phylogeny of Grosse et al. (2025 c), Tharyx robustus, as Tharyx sp. P, belongs to group IV (comprising members of Aphelochaeta, Kirkegaardia and Tharyx), clade T 1.	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFF9DFFABA079FDF5C060FA24.taxon	discussion	Remarks As the original material was described in detail, only the newly collected material is described here. While the characteristic spines of Tharyx were not observed in the material examined, all specimens examined were much smaller than the specimens used in the original descriptions. In addition, the material examined for this study was generally in poor to moderate condition, with many broken chaetae. Therefore, it is possible that the knob-like spines were not present in our material, but they may also not have been observed. However, the serrated transition spines figured in the original description could be observed and are illustrated here with SEM pictures. The specimens also present the typical thin and elongated body shape and head region of Tharyx. One specimen, GNM-POLYC 15682, was collected about 150 km north of the type locality in Sweden adding credit to the hypothesis that this species in indeed T. robustus as described by Blake & Göransson (2015). This species is distinguished from other species by the presence of serrated transition spines, that are absent in Tharyx killariensis, T. maryae and T. emmae sp. nov. as well as by the absence of long or beaded mid-body segments.	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFF9BFFA4A0EDFA2DC126FE3F.taxon	description	urn: lsid: zoobank. org: act: 6012 D 42 A- 2263 - 4112 - A 4 D 5 - 83 CBA 6946248 Figs 26 – 29	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFF9BFFA4A0EDFA2DC126FE3F.taxon	diagnosis	Diagnosis Thin, sometimes thread-like body with enlarged, bulgy venter around segments 9 – 20. Three peristomial rings covered by a narrow dorsal crest; dorsal tentacles and first branchiae arising from last peristomial ring. Up to seven sub-bidentate spines per neuro and notopodium posteriorly. Clear ventral bands on posterior half of enlarged anterior venter with methylene blue.	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFF9BFFA4A0EDFA2DC126FE3F.taxon	etymology	Etymology Tharyx emmae sp. nov. is named after Emma Woodhouse, one of the main characters of the novel Emma by Jane Austen.	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFF9BFFA4A0EDFA2DC126FE3F.taxon	materials_examined	Material examined Holotype NORTH ATLANTIC • Reykjanes Ridge, northern end; 63.33333 ° N, 23.16666 ° W; 305.3 m deep; 4 Sep. 2011; collected with box corer; SMF 33092. Paratypes NORTH ATLANTIC • 3 specs; same data as for holotype; SMF 33104, SMF 33095, SMF 33082 • 1 spec.; 63.31466 ° N, 23.16016 ° W; 293.6 m deep; 4 Sep. 2011; collected with epibenthic sledge; SMF 33102. NORTH SEA • 1 spec.; 60.396 ° N, 5.149 ° E; 172 m deep; 30 Mar. 2014; ZMBN 95791 • 1 spec.; 59.55444 ° N, 5.22245 ° E; 179 m deep; 28 Apr. 2017; ZMBN 125833 • 1 spec.; Hissfjorden; 60.17536 ° N, 5.96353 ° E; 182 m deep; 27 May 2020; ZMBN 139445 • 1 spec.; 60.39538 ° N, 5.15493 ° E; 172 m deep; 23 May 2018; ZMBN 174089 • 1 spec.; 60.39598 ° N, 5.14948 ° E; 172 m deep; 31 Mar. 2014; ZMBN 174088 • 1 spec.; 59.56729 ° N, 5.21568 ° E; 328 m deep; ZMBN 174095. NORWEGIAN SEA • 1 spec.; 61.17016 ° N, 7.24997 ° E; 146 m deep; 4 May 2017; ZMBN 174091 • 1 spec.; 63.67833 ° N, 9.79612 ° E; 120 m deep; 25 Oct. 2016; ZMBN 174094.	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFF9BFFA4A0EDFA2DC126FE3F.taxon	description	Description A small species. Holotype complete, 9 mm long (complete paratypes: 6 – 9 mm), 0.4 mm wide (complete paratypes: 0.2 – 0.4 mm), 106 segments (complete paratypes: 80 – 113 segments). Colour in ethanol light tan or gray to brown (Fig. 26). Body thin, sometimes thread-like, with a short, distinct expanded anterior region and sometimes a similar posterior region. Anterior 20 – 30 segments 6 – 8 times as wide and as high as long, round in cross section, venter expanded around segments 9 – 20 (Figs 26 A, C, 27 A – B). Following segments generally 3 times as wide and as high as long but in some specimens becoming up to as long as wide and high, round to oval in cross section. Posterior 20 – 30 segments 3 – 4 times as high as long and 3 – 6 times as wide as long. Dorsal groove or ridge absent. Longitudinal ventral ridge present along entire body (Fig. 26 F). Prostomium elongated, as long as two thirds of peristomium, conical, without rings; eyespots absent; nuchal organs simple slits on posterolateral margins (Fig. 27). Peristomium as long as 6 – 7 anterior segments, three rings of similar size, anterior one extending dorsally, overlapping prostomium; thin dorsal crest along entire length, often ending in a bidentate tip anteriorly (Fig. 27). Dorsal tentacles arising from last peristomial ring, close together. First pair of branchiae arising from last peristomial ring, posterior to dorsal tentacles (Fig. 27). Second pair of branchiae arising from chaetiger 1, dorsal to and slightly posterior to parapodia (Fig. 27). Subsequent branchiae similarly placed, branchiae and branchial scars present along most anterior segments, less frequent afterwards. Parapodia biramous, placed dorsally, forming distinct shoulders anteriorly (Fig. 27), shifting to median position in midbody and a more ventral position posteriorly. Chaetae capillaries and spines; with 7 – 10 capillary chaetae per each neuro- and notopodium anteriorly, capillaries of midbody, short, smooth. Up to 7 sub-bidentate spines per each neuro- and notopodium in posterior half of the body, long, thin and slightly curved (Fig. 28), companion capillary chaetae lacking. Pygidium with terminal anus and small, rounded ventral lobe. Methylene blue The venter stains a light blue colour anteriorly, except for segments 9 to 13 (Fig. 27 A). Segments 14 to 18 retain dark ventral bands even after the rest of the stain has faded. Intersegmental lines and a longitudinal line may stain on the dorsum. The tip of the prostomium and the top of the third peristomial ring may retain a dark colour.	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFF9BFFA4A0EDFA2DC126FE3F.taxon	distribution	Distribution and habitats The material examined here has been collected in the North Atlantic south of Iceland on the northern end of the Reykjanes ridge as well as along the Norwegian coast from depths of 120 to 305 m (Fig. 29).	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFF9BFFA4A0EDFA2DC126FE3F.taxon	description	Phylogenetic placement In the phylogeny of Grosse et al. (2025 c), Tharyx emmae sp. nov., as Tharyx sp. L, belongs to group IV (comprising members of Aphelochaeta, Kirkegaardia and Tharyx), clade T 1. It is sister the clade comprising Tharyx killariensis and another unnamed species of Tharyx.	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
B6558E4AFF9BFFA4A0EDFA2DC126FE3F.taxon	discussion	Comparative remarks Tharyx emmae sp. nov. is different from all other described species of Tharyx by its enlarged and expanded venter anteriorly, a high number of spines in posterior segments (up to seven per neuro and notopodium vs, e. g., up to four in T. killariensis) as well as its unique methylene blue staining pattern that reveals several ventral bands in anterior segments.	en	Grosse, Maël, Nygren, Arne, Capa, María (2026): Revision of some coastal species of bitentaculate Cirratulidae (Annelida, Cirratulida) from the North-East Atlantic. European Journal of Taxonomy 1076: 1-46, DOI: 10.5852/ejt.2026.1076.3304, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3304/14544
