identifier	taxonID	type	CVterm	format	language	title	description	additionalInformationURL	UsageTerms	rights	Owner	contributor	creator	bibliographicCitation
4F38C920CA0BD605FD83A299B5BEF879.text	4F38C920CA0BD605FD83A299B5BEF879.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Chaetocirratulus Blake 2018	<div><p>Genus  Chaetocirratulus Blake, 2018</p><p>Chaetocirratulus Blake, 2018: 56 .</p><p>Type species</p><p>Heterocirrus andersenensis Augener, 1932 . Original designation by Blake (2018).</p><p>Diagnosis (after Blake 2018)</p><p>Prostomium broadly rounded anteriorly or wedge-shaped; eyespots absent; with a pair of small nuchal organs as slits or depressions at posterior edge. Peristomium with a single pair of grooved dorsal tentacles arising from posterior margin or interface with chaetiger 1. First pair of branchiae arising from posterior margin of peristomium, an achaetous segment, or chaetiger 1. Body typically thick and fusiform over many segments, rarely with middle or posterior body segments beaded or moniliform; individual segments short, numerous. Setae include capillaries on most chaetigers and thick, pointed spines in neuropodium and a few in notopodium or spines in neuropodium only; spines few, often small and inconspicuous, not forming cinctures. Individual spines straight to weakly sigmoid. Pygidium a simple ventral lobe.</p></div>	https://treatment.plazi.org/id/4F38C920CA0BD605FD83A299B5BEF879	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	Grosse, Maël;Alvestad, Tom;Nygren, Arne;Kongsrud, Jon Anders	Grosse, Maël, Alvestad, Tom, Nygren, Arne, Kongsrud, Jon Anders (2025): Phylogenetic analyses elucidate the identity and distribution of two early-described species of Arctic Cirratulidae (Annelida, Sedentaria). European Journal of Taxonomy 987: 189-220, DOI: 10.5852/ejt.2025.987.2869, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2869/13037
4F38C920CA0AD612FE01A2AAB7E0FA50.text	4F38C920CA0AD612FE01A2AAB7E0FA50.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Chaetocirratulus abranchiatus (Hansen 1879) Grosse & Alvestad & Nygren & Kongsrud 2025	<div><p>Chaetocirratulus abranchiatus (Hansen, 1879) comb. nov.</p><p>Figs 3–9</p><p>Cirratulus (?)  abranchiatus Hansen, 1879: 10, pl. VII figs 3–7.</p><p>Chaetozone abranchiata – Hartman 1959: 401.</p><p>Diagnosis</p><p>In adults, short anterior region distinctively narrower than following segments; prostomium broadly triangular, three rings visible dorsally, two ventrally, dorsal crest absent; wide ventral ridge.</p><p>Type material</p><p>Neotype (here designated)</p><p>NORWEGIAN SEA • 64.10522° N, 5.72433° E; depth 636 m; 27 Jun. 2007; collected with RP sledge; MAREANO sample R932-75, RP; fixed in 96% ethanol; ZMBN 136930.</p><p>Other material examined</p><p>ARCTIC OCEAN • 4 specs; 81.60734° N, 33.40031° E; depth 518 m; 27 Jun. 2022; collected with grab; MAREANO sample R2915-55, GR; fixed in 96% ethanol; DNA voucher: MG1126; ZMBN 149490 •  1 spec.; 81.34727° N, 21.99029° E; depth 458 m; 2 Jul. 2022; collected with grab; MAREANO sample R2963-79, GR; fixed in 96% ethanol; ZMBN 149491 •  1 spec.; 81.41596° N, 21.67928° E; depth 704 m; 5 Jul. 2022; collected with grab; MAREANO sample R2983-90, GR; fixed in 96% ethanol; ZMBN 149492 .</p><p>BARENTS SEA • 1 spec.; 71.92061° N, 20.38130° E; depth 349 m; 1 Jun. 2019; MetaMon project; collected with grab; sample GE-09; fixed in 96% ethanol; ZMBN 136914 .</p><p>GREENLAND SEA – <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=-23.69633&amp;materialsCitation.latitude=67.86783" title="Search Plazi for locations around (long -23.69633/lat 67.86783)">Denmark Strait</a> • 4 specs; 67.86783° N, 23.69633° W; depth 1281 m; 15 Sep. 2011; collected with RP sledge; IceAGE sample M85-3 1144; fixed in 96% ethanol; SMF 32846, 32847, 32832, 32833  •  1 spec.; same data as for preceding; DNA voucher: MG810; no repository (specimen used for SEM) •  2 specs; 67.21383° N, 26.22516° W; depth 700 m; 14 Sep. 2011; collected with CliSAP sledge; IceAGE sample M85-3 1119; fixed in 96% ethanol; SMF 32876, 32877 •  2 specs; 67.837° N, 23.702° W; depth 1241 m; 15 Sep. 2011; collected with box corer; IceAGE sample M85-3 1142; fixed in 96% ethanol; SMF 32809, 32863 •  1 spec.; same data as for preceding; DNA voucher: MG978; no repository (specimen used for SEM) •  3 specs; 67.8465° N, 23.696° W; depth 1249 m; 15 Sep. 2011; collected with epibenthic sledge; IceAGE sample M85-3 1148; fixed in 96% ethanol; SMF 32864 to 32866 •  1 spec.; same data as for preceding; DNA voucher: MG984; no repository (specimen used for SEM) •  2 specs; 67.84° N, 23.696° W; depth 1250 m; 15 Sep. 2011; collected with epibenthic sledge; sample IceAGE M85-3 1148; fixed in 96% ethanol; SMF 32884, 32885 •  1 spec.; 67.86783° N, 23.69616° W; depth 1270 m; 15 Sep. 2011; collected with epibenthic sledge; IceAGE sample M85-3 1144; fixed in 96% ethanol; SMF 32886 •  1 spec.; 67.21383° N, 26.2075° W; depth 716 m; 14 Sep. 2011; collected with RP sledge; IceAGE sample M85-3 1123; fixed in 96% ethanol; SMF 32834.  – <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=-26.2075&amp;materialsCitation.latitude=67.21383" title="Search Plazi for locations around (long -26.2075/lat 67.21383)">Fram Strait</a> • 1 spec.; 79.03412° N, 7.26576° E; depth 1275 m; 27 Oct. 2019; collected with grab; MAREANO sample R2099-2155, GR; fixed in 96% ethanol; ZMBN 136920  •  1 spec.; 79.1385° N, 6.08217° E; depth 1282 m; 10 Jul. 2017; Hausgarten project; collected with UNSEL box corer; fixed in 96% ethanol; ZMBN 144610 •  1 spec.; 78.9888° N, 5.432° E; depth 995 m; 2 Jul. 2016; Hausgarten project; fixed in 96% ethanol; ZMBN 130912 •  1 spec.; 79.08467° N, 6.45138° E; depth 1235 m; 29 Sep. 2019; collected with grab; MAREANO sample R2107-2163, GR; fixed in 96% ethanol; ZMBN 144613 •  1 spec.; 79.10622° N, 6.15371° E; depth 1235 m; 29 Sep. 2019; collected with grab; MAREANO sample R2108-115, GR; fixed in 96% ethanol; mounted on SEM-stub; ZMBN 144614 •  12 specs; 79.11608° N, 6.15363° E; depth 1229 m; 29 Sep. 2019; collected with beam trawl; MAREANO sample R2108-18, BT; fixed in 96% ethanol; ZMBN 144615 •  5 specs; 79.10649° N, 6.15297° E; depth 1262 m; 29 Sep. 2019; collected with RP sledge; MAREANO sample R2108-21, RP; fixed in 96% ethanol; DNA vouchers: MG1173, MG1174; ZMBN 144616 •  1 spec.; same data as for preceding; mounted on SEMstub; ZMBN 144616 -SEM •  12 specs; 79.10189° N, 6.15166° E; depth 1238 m; 30 Sep. 2019; collected with RP sledge; MAREANO sample R2108-22, RP; fixed in 96% ethanol; ZMBN 144617 •  8 specs; 79.10372° N, 6.15409° E; depth 1236 m; 30 Sep. 2019; collected with RP sledge; MAREANO sample R2108-23, RP; fixed in 96% ethanol; DNA voucher: MG1172; ZMBN 144618, 144619 •  1 spec.; same data as for preceding; mounted on SEM-stub; ZMBN 144618 -SEM •  1 spec.; 78.98620° N, 7.24162° E; depth 1232 m; 30 Sep. 2019; collected with grab; MAREANO sample R2114-2170, GR; fixed in 96% ethanol; ZMBN 144620 .</p><p>NORWEGIAN SEA • 3 specs; 63.41033° N, 8.187° W; depth 687 m; 31 Jul. 2913; collected with epibenthic sledge; IceAGE 2 sample POS456 880; fixed in 96% ethanol; SMF 32868 to 32870 •  5 specs; 63.09366° N, 8.572° W; depth 500 m; 31 Jul. 2013; collected with epibenthic sledge; IceAGE 2 sample POS456 879; fixed in 96% ethanol; SMF 32881 to 32883, 32862, 32811 •  1 spec.; 63.57766° N, 7.7115° W; depth 1044 m; 1 Aug. 2013; collected with brenke sledge; IceAGE 2 POS456 881; fixed in 96% ethanol; SMF 32803 •  1 spec.; 66.84333° N, 7.8945° E; depth 735 m; 2 Sep. 2015; collected with RP sledge; IceAGE 2 sample R1569-179, RP; fixed in 96% ethanol; ZMBN 120504 •  1 spec.; 64.10311° N, 5.73214° E; depth 626 m; 27 Jun. 2013; collected with beam trawl; MAREANO sample R932-454, BT; fixed in 96% ethanol; ZMBN 144621 •  4 specs; 62.553° N, 0.981° E; depth 800 m; 16 Aug. 1981; R/V “ H. Mosby ” sample HM81.08.16.7; fixed in formaldehyde and transferred to 75% ethanol; ZMBN 144594 •  3 specs; 62.491° N, 1.721° E; depth 604 m; 21 Jan. 1982; R/V “ H. Mosby ” sample HM82.01.21.2; fixed in formaldehyde and transferred to 75% ethanol; ZMBN 144595 •  4 specs; 62.56° N, 0.981° E; depth 804 m; 21 Jan. 1982; R/V “ H. Mosby ” sample HM82.01.21.4; fixed in formaldehyde and transferred to 75% ethanol; ZMBN 144596 •  2 specs; 62.198° N, 0.003° W; depth 708 m; 2 Jun. 1983; R/V “ H. Mosby ” sample HM83.06.02.1; fixed in formaldehyde and transferred to 75% ethanol; ZMBN 144597 •  10 specs; 61.343° N, 3.185° W; depth 1338 m; 3 Jun. 1983; R/V “ H. Mosby ” sample HM83.06.03.1; fixed in formaldehyde and transferred to 75% ethanol; ZMBN 144598 •  1 spec.; 65.168° N, 9.493° W; depth 784 m; 8 Jun. 1983; R/V “ H. Mosby ” sample HM83.06.08.1; fixed in formaldehyde and transferred to 75% ethanol; ZMBN 144599 •  11 specs; 62.593° N, 1.233° E; depth 781 m; 17 Jun. 1983; R/V “ H. Mosby ” sample HM83.06.17.3; fixed in formaldehyde and transferred to 75% ethanol; ZMBN 144600 •  2 specs; 62.585° N, 1.793° E; depth 656 m; 23 May 1984; R/V “ H. Mosby ” sample HM84.05.23.1; fixed in formaldehyde and transferred to 75% ethanol; ZMBN 144601 •  20 specs; 62.508° N, 1.851° E; depth 576 m; 23 May 1984; R/V “ H. Mosby ” collected with RP sledge; sample HM84.05.23.3; fixed in formaldehyde and transferred to 75% ethanol; ZMBN 144602 •  5 specs; 62.603° N, 2.233° E; depth 576 m; 23 May 1984; Brattegards exped.; collected with RP sledge; sample HM84.05.23.5; fixed in formaldehyde and transferred to 75% ethanol; ZMBN 144603 •  1 spec.; 62.553° N, 1.82° E; depth 652 m; 21 Nov. 1984; R/V “ H. Mosby ” collected with RP sledge; sample HM84.11.21.2; fixed in formaldehyde and transferred to 75% ethanol; ZMBN 144604 •  3 specs; 62.706° N, 1.186° E; depth 897 m; 8 Nov. 1885; R/V “ H. Mosby ” collected with RP sledge; sample HM85.01.08.2; fixed in formaldehyde and transferred to 75% ethanol; ZMBN 144605 •  2 specs; 63.045° N, 7.028° W; depth 1022 m; 13 Jun. 1986; R/V “ H. Mosby ” collected with RP sledge; sample HM86.06.13.4; fixed in formaldehyde and transferred to 75% ethanol; ZMBN 144606 •  9 specs; 62.948° N, 7.002° W; depth 748 m; 13 Jun. 1986; R/V “ H. Mosby ” collected with D sledge; sample HM86.06.13.5; fixed in formaldehyde and transferred to 75% ethanol; ZMBN 144607 •  1 spec.; 62.855° N, 5.698° W; depth 750 m; 16 Jun. 1986; R/V “ H. Mosby ” collected with D sledge; sample HM86.06.16.1; fixed in formaldehyde and transferred to 75% ethanol; ZMBN 144608 •  2 specs; 62.61° N, 1.573° E; depth 654 m; 15 Jun. 1986; R/V “ H. Mosby ” collected with RP sledge; sample HM86.08.15.5; fixed in formaldehyde and transferred to 75% ethanol; ZMBN 144609 •  1 spec.; 63.59067° N, 5.57533° E; depth 763 m; 20 Jun. 2014; collected with beam trawl; MAREANO sample R1349-274, BT; fixed in 96% ethanol; ZMBN 144611 •  1 spec.; 66.84067° N, 7.88867° E; depth 734 m; 2 Sep. 2015; collected with beam trawl; MAREANO sample R1569-553, BT; fixed in 96% ethanol; ZMBN 144612 •  1 spec.; 63.59067° N, 5.57533° E; depth 763 m; 20 Jun. 2014; collected with beam trawl; MAREANO sample R1349-274, BT; fixed in 96% ethanol; ZMBN 162355 •  1 spec.; 68.28796° N, 10.70476° E; depth 689 m; 28 Apr. 2012; collected with beam trawl; MAREANO sample R763-001; fixed in 96% ethanol; ZMBN 162356 •  1 spec.; 67.59864° N, 9.31061° E; depth 918 m; 5 May 2012; collected with RP sledge; MAREANO sample R818-9, RP; fixed in 96% ethanol; ZMBN 162357 •  4 specs; 62.42324° N, 1.20725° E; depth 654 m; 2 May 2021; collected with grab; MAREANO sample R2531-101, GR; fixed in 96% ethanol; DNA voucher: BeMG457; ZMBN 162348 •  2 specs; 64.74521° N, 5.19276° E; depth 707 m; 9 May 2021; collected with grab; MAREANO sample R2574-216, GR; fixed in 96% ethanol; DNA voucher: BeMG460; ZMBN 162349 •  1 spec.; 64.73235° N, 5.41943° E; depth 631 m; 9 May 2021; collected with grab; MAREANO sample R2577-220, GR; fixed in 96% ethanol; DNA voucher: BeMG458; ZMBN 162350 .</p><p>Description</p><p>Neotype incomplete, 12 mm long, 2.5 mm wide, 50 segments (Fig. 3). Other complete specimens range from 3 to 21 mm long, 0.5 to 5 mm wide and 34 to 59 segments (Fig. 4A–N). Colour in ethanol light tan to light grey, old formalin fixed specimens with light pink colour. Body short and stout, of uniform width and height abruptly tapering at both extremities or with a distinct enlarged anterior half and posterior tail; anterior up to twice as wide as posterior, tapering towards pygidium (Fig. 4A–N). In larger specimens, first 6–8 segments not enlarged, slightly wider than pre-chaetiger area, and approximately as wide as tall. Smaller specimens often round in cross section, larger specimen oval to dorso-ventrally flattened. Specimens fixed in tubes with much thinner shape, with constant width (Fig. 4M). Dorsal groove or ridge nearly always absent, rarely a thin dorsal groove anteriorly. A wide ventral ridge made from segmental pads along entire body.</p><p>Prostomium half as long as peristomium, broadly triangular, without rings; eyespots absent; nuchal organs simple slits at posterior lateral margin (Figs 5A–E, 6A–C). Peristomium as long as four anterior chaetigers, with three distinct rings, anterior one longer with prominent rounded dorsum slightly overlapping prostomium anteriorly, anterior and middle rings fused ventrally with, middle and posterior rings each slightly wider and as long as anterior chaetigers (Figs 5A–E, 6A–C). Dorsal tentacles arising between last peristomial ring and chaetiger 1, well separated (Figs 5A–B, D–E, 6A–C). First pair of branchiae arising between last peristomial ring and chaetiger 1, lateral to tentacles (Figs 5A–B, D–E, 6A–C). Second pair of branchiae arising from chaetiger 1, dorsal and slightly posterior to parapodia. Subsequent branchiae similarly placed, branchiae or branchial stubs present on all chaetiger on enlarged anterior half (Fig. 6A, D), absent from posterior region (Figs 6E, 7A).</p><p>Parapodia biramous, low mounds or ridges distinct in larger specimens. Capillary chaetae 4–6 per neuropodium; 5–10 per notopodium, arranged in two rows; 2–4 capillary chaetae per neuropodium and notopodium are longer than body width in anterior region, each finely serrated along one edge (Fig. 7C–E). Short capillary chaetae progressively transition to thicker chaetae to 2–3 straight spines per neuropodium and notopodium in posterior half, with 2–4 alternating capillary chaetae, long, straight and slender (Fig. 7F).</p><p>Pygidium with terminal anus and short, rounded ventral lobe (Fig. 7A–B).</p><p>Methylene blue</p><p>Use of methylene blue results in variable patterns. All specimens retain a uniform light blue colour, branchiae retain a dark colour usually accompanied by dark blue spots spread at least over the proximal half. On some specimens sparse to very dense dark blue spots can be observed on the prechaetigerous area as well as on the first 5–6 parapodia.</p><p>Biology</p><p>Some specimens have been observed partially inside sandy tubes (Fig. 4). This phenomenon has previously been observed in  Chaetocirratulus gayheadius (Hartman, 1965) where the tubes were assumed to be made by  C. gayheadius which was considered unusual among cirratulids where tubes, when present, are usually muddy (Blake 2022). However, when examining bulk samples, such tubes were found in various sizes and occupied by a variety of animals and seem more likely to be made by some other organism such as Foraminifera d’Orbigny, 1826 and opportunistically occupied or temporarily crawled through by  C. abranchiatus comb. nov.</p><p>A few of the larger specimens were found with eggs in the body cavity. While numerous examples of asexual reproduction and budding were found in  C. gayheadius (Blake 2022), none was observed in the material examined for  C. abranchiatus comb. nov.</p><p>Distribution</p><p>This species is distributed all around the North-East Atlantic on continental shelves and slopes (Fig. 8).</p><p>Comparative remarks</p><p>So far,  Chaetocirratulus abranchiatus comb. nov. is the only member of its genus recorded from the North-East Atlantic. There are several other species occurring in the North-West Atlantic. Among them,  Chaetocirratulus gayheadius is, as far as we can tell, closely related to  C. abranchiatus . The North-East Atlantic species agree well with the description of the West Atlantic species (Blake 2022), except for the methyl green/methylene blue staining pattern. Indeed, while some specimens examined in this study show the same pattern as described for the North American species, this pattern is variable as not all specimens retain a dark stain. This variation in staining pattern is seen among specimens collected together in the same sample, which partially excludes collection, fixation or preservation artefacts and could be due instead to intraspecific variability, specimen maturity or sexual dimorphism.</p><p>However, cryptic diversity is common in  Cirratulidae (Grosse et al. 2020), and the known distribution of the two species is restricted to different biogeographical regions (Costello et al. 2017). In addition, asexual reproduction and budding are well documented for  C. gayheadius (Blake 2022), but not observed in  C. abranchiatus comb. nov. (this study). Therefore, we do not at this stage propose to synonymize the two species until genetic information can be obtained from specimens identified as  C. gayheadius .</p><p>Remarks on the original description and illustrations and on the neotype</p><p>No type material could be found for this species and no mention is made of type specimens in the original description. All the existing material from the N.N.H.E. expeditions is kept at the Bergen University Natural History Museum and the Natural History Museum in Oslo. However, no specimens of  Chaetocirratulus abranchiatus comb. nov. was found in either collection, and there are no records of it in the archives and the protocols of the museums. Therefore, we conclude that the original specimens were never deposited in any collection and a neotype has to be designated. The specimen designated as neotype in this study was chosen as it was collected the closest to the type locality, about 135 km, and sequences were available for it. While it is incomplete (part of the posterior region is missing), none of the specimens in better condition were collected so close to the type locality.</p><p>The original description was short, as was often the case in those times. It was however informative enough with regards to the body shape, the shape of the prechaetiger area and the shape of the parapodia in particular. One point of disagreement between the original description and our observations is on the capillary chaetae that were described as perfectly smooth. This can be explained by the techniques available at the time as the characteristic serrations present on the capillary chaetae of  Chaetocirratulus abranchiatus comb. nov., while easily observed with SEM, are difficult to see even with modern light microscopy (Fig. 7E). Compared to the description, the original illustrations were particularly informative, as they show very well the distinctive body shape and anterior morphology of this species (Fig. 9). In addition to the fact that some specimens studied in this work were collected close to the type locality, this leaves no doubt about the fact that the specimens examined by Hansen for his description and the specimens examined for this study belong to the same species.</p></div>	https://treatment.plazi.org/id/4F38C920CA0AD612FE01A2AAB7E0FA50	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	Grosse, Maël;Alvestad, Tom;Nygren, Arne;Kongsrud, Jon Anders	Grosse, Maël, Alvestad, Tom, Nygren, Arne, Kongsrud, Jon Anders (2025): Phylogenetic analyses elucidate the identity and distribution of two early-described species of Arctic Cirratulidae (Annelida, Sedentaria). European Journal of Taxonomy 987: 189-220, DOI: 10.5852/ejt.2025.987.2869, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2869/13037
4F38C920CA1CD612FDEFA2FFB6DEF82E.text	4F38C920CA1CD612FDEFA2FFB6DEF82E.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Aphelochaeta Blake 1991	<div><p>Genus  Aphelochaeta Blake, 1991</p><p>Aphelochaeta Blake, 1991: 28 .</p><p>Type species</p><p>Aphelochaeta monilaris Hartman, 1960 . Original designation by Blake (1991).</p><p>Diagnosis (after Blake 2018)</p><p>Prostomium conical to rounded; peristomium elongate with pair of grooved dorsal tentacles arising either on or anterior to chaetiger 1. Anterior segments often expanded, crowded or uncrowded; abdominal segments sometimes beaded or moniliform in appearance; chaetae simple capillaries lacking distinct serration using light microscopy but distinct fibrils may be visible using SEM; posterior end frequently expanded tapering to a simple pygidial lobe.</p></div>	https://treatment.plazi.org/id/4F38C920CA1CD612FDEFA2FFB6DEF82E	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	Grosse, Maël;Alvestad, Tom;Nygren, Arne;Kongsrud, Jon Anders	Grosse, Maël, Alvestad, Tom, Nygren, Arne, Kongsrud, Jon Anders (2025): Phylogenetic analyses elucidate the identity and distribution of two early-described species of Arctic Cirratulidae (Annelida, Sedentaria). European Journal of Taxonomy 987: 189-220, DOI: 10.5852/ejt.2025.987.2869, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2869/13037
4F38C920CA1FD619FE63A602B64BFA24.text	4F38C920CA1FD619FE63A602B64BFA24.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Aphelochaeta abyssorum (Hansen 1879) Grosse & Alvestad & Nygren & Kongsrud 2025	<div><p>Aphelochaeta abyssorum (Hansen, 1879) comb. nov.</p><p>Figs 10–16</p><p>Cirratulus (?)  abyssorum Hansen, 1879: 10, pl. VII fig. 1.</p><p>Cirratulus abyssorum – Hartman 1959: 402.</p><p>Diagnosis</p><p>Body long and slender, segments never beaded, anterior dorso-ventrally flattened; three peristomial rings, dorsal crest present, pigmentation absent; latero-ventral bands anteriorly with MB.</p><p>Type material</p><p>Lectotype</p><p>NORWEGIAN SEA • anterior fragment; <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=5.35&amp;materialsCitation.latitude=64.2" title="Search Plazi for locations around (long 5.35/lat 64.2)">Vøringen</a>; 64.2° N, 5.35° E; depth 911 m; 1876–1878; N.N.H.E. stn 87; clay; ZMBN 1970.</p><p>Paralectotypes</p><p>NORWEGIAN SEA • 7 intermediate fragments; same data as for lectotype; ZMBN 1970.</p><p>Other material examined</p><p>ARCTIC OCEAN • 1 spec.; 81.89659° N, 9.85533° E; depth 834 m; 8 Jun. 2017; collected with box corer; R/V Polarstern sample PS 106-1; fixed in 96% ethanol; DNA voucher: MG751; no repository (specimen used for SEM) .</p><p>GREENLAND SEA • 1 spec.; 67.63266° N, 26.76650° W; depth 316 m; 14 Sep. 2011; collected with CliSAP sledge; IceAGE sample M 85-3 1136; fixed in 96% ethanol; SMF 32821 •  1 spec.; 67.21383° N, 26.22516° W; depth 697 m; 14 Sep. 2011; collected with CliSAP sledge; sample IceAGE M85-3 1119; fixed in 96% ethanol; SMF 32810, 32856 •  1 spec.; 67.83700° N, 23.70200° W; depth 1241 m; 15 Sep. 2011; collected with box corer; IceAGE sample M85-3 1142; fixed in 96% ethanol; SMF 32857 •  3 specs; 67.63800° N, 26.75466° W; depth 318 m; 14 Sep. 2011; collected with epibenthic sledge; IceAGE sample M85-3 1132; fixed in 96% ethanol; SMF 32871, 32872, 32808 .</p><p>NORTH ATLANTIC • 1 spec.; 63.33333° N, 23.16666° W; depth 305 m; 4 Sep. 2011; collected with box corer; sample IceAGE M85-3 1031; fixed in 96% ethanol; SMF 32839 .</p><p>NORWEGIAN SEA • 1 spec.; 63.38933° N, 8.157° W; depth 687 m; 31 Jul. 2013; collected with brenke sledge; IceAGE 2 sample POS456 880; fixed in 96% ethanol; DNA voucher: MG597; no repository (specimen used for SEM) •  1 spec.; 61.77600° N, 3.87333° W; depth 834 m; 28 Jul. 2013; collected with grab; IceAGE 2 sample POS456 880; fixed in 96% ethanol; SMF 32822 •  2 specs; 62.75533° N, 0.89900° W; depth 1571 m; 26 Jul. 2013; collected with grab; sample IceAGE 2 POS456 871; fixed in 96% ethanol; SMF 32829, 32835 •  1 spec.; 66.30100° N, 12.37333° W; depth 732 m; 22 Sep. 2011; collected with box corer; IceAGE sample M85-3 1217; fixed in 96% ethanol; SMF 32836 •  1 spec.; 62.20866° N, 0.26200° E; depth 669 m; 25 Jul. 2013; collected with box corer; IceAGE sample POS456 868; fixed in 96% ethanol; DNA voucher: MG779; no repository (specimen used for SEM) •  1 spec.; 66.53816° N, 12.86483° W; depth 316 m; 22 Sep. 2011; collected with RP sledge; IceAGE sample M85-3 1209; fixed in 96% ethanol; SMF 32837 •  1 spec.; 67.07866° N, 13.06383° W; depth 1575 m; 21 Sep. 2011; IceAGE sample M85-3 1191; fixed in 96% ethanol; SMF 32838 •  1 spec.; 63.57766° N, 7.74650° W; depth 1043 m; 1 Aug. 2013; collected with epibenthic sledge; IceAGE 2 sample POS456 881; fixed in 96% ethanol; SMF 32867 •  12 specs; 63.09366° N, 8.57200° W; depth 511 m; 31 Jul. 2013; DZMB exped; collected with epibenthic sledge; IceAGE 2 sample POS456 879; fixed in 96% ethanol; SMF 32823, 32806, 32873, 32874, 32887, 32848 to 32854 •  1 spec.; same data as for preceding; DNA voucher: MG1055; no repository (specimen used for SEM) •  26 specs; 63.41733° N, 10.96633° W; depth 441 m; 2 Aug. 2013; collected with epibenthic sledge; IceAGE 2 sample POS456 882; fixed in 96% ethanol; SMF 32855, 32812, 32840 to 32845, 32814 to 32820, 32824 to 32828, 32875, 32830, 32831, 32858 to 32860 •  1 spec.; same data as for preceding; DNA voucher: MG738; no repository (specimen used for SEM) •  1 spec.; same data as for preceding; DNA voucher: MG839; no repository (specimen used for SEM) •  1 spec.; same data as for preceding; DNA voucher: MG950; no repository (specimen used for SEM) •  1 spec.; same data as for preceding; DNA voucher: MG953; no repository (specimen used for SEM) •  1 spec.; same data as for preceding; DNA voucher: MG765; no repository (specimen used for SEM) •  1 spec.; 63,64533° N, 7,7858°3 W; depth 1080 m; 1 Aug. 2013; collected with grab; sample IceAGE 2 sample POS456 881; fixed in 96% ethanol; SMF 32861 .</p><p>Description</p><p>Mostly based on lectotype and 10 newly collected complete specimens. Lectotype ovigerous female in eight fragments including anterior and posterior end for about 30 mm, up to 1 mm wide (Fig. 10). Ten complete specimens 13 to 20 mm long, 0.5 to 0.9 mm wide for 87 to 139 segments (Fig. 11A–F). Colour in ethanol light tan or cream to light grey, venter often lighter than dorsum. Body elongate; short anterior region distinct, flattened, nearly twice as wide as midbody; midbody segments cylindrical, never longer than wide or high, never beaded; short posterior region enlarged, tapering towards pygidium. Anterior 22–27 segments 12–14 times as wide as and 4–9 times as high as long, oval in cross section. Midbody segments progressively lengthening to 2–3 times as wide and high as long, round in cross section, with distinct, thin and shallow transversal intersegmental grooves, never beaded or moniliform. Posterior 20–50 segments 5–8 times as wide as and 3–6 times as high as long, oval to flattened in cross section, sometimes distinctly enlarged over anteriormost segments and tapering towards pygidium. A thin, shallow dorsal groove sometimes present over posterior enlarged region. A wide, low ventral ridge present along entire body (Figs 12A, 15D).</p><p>Prostomium one third to half as long as peristomium, broad, conical, without rings; eyespots absent; nuchal organs simple slits on posterolateral margins (Figs 12A–C, 13A–C). Peristomium as long as 6–7 anterior segments, generally longer than wide, with three distinct rings visible laterally and ventrally, incomplete over dorsum due to broad, elongate dorsal crest, overlapping chaetiger 1 between dorsal tentacles, often higher than first 2–4 chaetigers (Figs 12A–C, 13A–C). Dorsal tentacles arising from posterior margin of peristomium, medial to parapodium of chaetiger 1, well separated. First pair of branchiae arising lateral to dorsal tentacles on anterior margin of chaetiger 1 (Figs 12A–C, 13A–C). Second pair of branchiae arising from chaetiger 1, directly above and slightly posterior to parapodia (Figs 12B–C, 13A–C). Subsequent branchiae similarly placed, present on nearly all anterior chaetigers, occasionally along first half of body, and rarely along posterior half.</p><p>Parapodia biramous, low mounds to inconspicuous, placed high over anterior region forming distinct shoulders (Figs 12B–C, 13A–C), shifting to a medium position in midbody (Fig. 14A–B) and a ventral position along posterior enlarged region (Fig. 12D). Chaetae all capillaries 7–10 per neuropodium, 16– 19 per notopodium, typically arranged on two rows; neurochaetae short, 1–2 per neuropodium as long as notochaetae in midbody, basally strongly curved upwards in anterior segments, gradually straightening but retaining a light curvature throughout, covered in fine, short, dense scales on concave side made by protruding fibrils; notochaetae 1–2 times as long as body width in anterior and midbody, directed nearly upwards anteriorly, shifting laterally in midbody, covered in long, pointy, flat scales along one side (Fig. 14C–F); posterior neuro- and notochaetae short.</p><p>Pygidium with terminal anus, reduced with large rounded ventral lobe and 5 small dorsal lobes (Fig. 15E).</p><p>Methylene blue</p><p>Prostomium and peristomium retain a light stain without any particular pattern, although the dorsal crest is generally of a lighter colour and some longitudinal lines stay unstained. Distinct latero-ventral bands are present from segment 10–13 and fade in midbody where only faint lines of dark dots remain. More anterior segments retain a light stain laterally and ventrally over the posterior half of each segment. Bands of dark dots can be present dorsally over anterior segments (Fig. 15A–C).</p><p>Distribution and habitat</p><p>Aphelochaeta abyssorum comb. nov. is widely distributed at shelf and slope depths (300–1500 m deep) from the Arctic Ocean around Svalbard to the Norwegian Sea and Denmark Strait (Fig, 16).</p><p>Remarks</p><p>Hansen (1879) reported 3 specimens from the same station (N.N.H.E stn 87) in the original description of  C. abyssorum . The type material for this taxon (ZMBN 1970) has been located in the collections of the University Museum of Bergen (Oug et al. 2014). However, the sample ZMBN 1870 includes only a single anterior fragment and 7 midbody fragments. The anterior fragment is in close agreement with the original description given by Hansen (1879, 1882) and is here designated the lectotype. The remaining midbody fragments may belong to other specimens and are considered paralectotypes.</p><p>In some specimens, the posterior end is not particularly enlarged. In smaller specimens, the anterior part is not always much wider, but nearly always flatter and with the notopodium forming distinct shoulders. In the smallest fragments (possibly juveniles) the prostomium is as long as the peristomium, the peristomial rings are not as distinct and the prechaetiger area is overall more elongated and cylindrical.</p><p>The genus  Aphelochaeta is one of the least studied genera among the bitentaculate  Cirratulidae . Some species have been studied in the Pacific (Blake 1991, 2018, 2019; Dean &amp; Blake 2016), the Southern Ocean (Blake 2023) and to a small extent the West Atlantic (Elías &amp; Rivero 2009; Blake &amp; Dean 2019). However, these studies mostly concern species living in coastal waters or abyssal depths and very little is known about species living at shelf and slope depths. In the North-East Atlantic, very little is known about the genus in general. Only a few species have been described, all from coastal waters. In addition, as was the case in the present study, most of these descriptions are old, inadequate and need to be updated. Therefore, diversity of the genus  Aphelochaeta in the area has never been properly surveyed and assessed. A revision of the genus in Europe is necessary to both properly re-describe known species and identify potential new species.</p></div>	https://treatment.plazi.org/id/4F38C920CA1FD619FE63A602B64BFA24	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	Grosse, Maël;Alvestad, Tom;Nygren, Arne;Kongsrud, Jon Anders	Grosse, Maël, Alvestad, Tom, Nygren, Arne, Kongsrud, Jon Anders (2025): Phylogenetic analyses elucidate the identity and distribution of two early-described species of Arctic Cirratulidae (Annelida, Sedentaria). European Journal of Taxonomy 987: 189-220, DOI: 10.5852/ejt.2025.987.2869, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2869/13037
