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Polyophthalmus zhadanae sp. nov. (Annelida, Opheliidae), is described from the coast of Kuwait and Saudi Arabia (Arabian Gulf) after specimens collected in the intertidal and shallow subtidal. This new species is characterised by the body pigmentation pattern, distribution of lateral eyes, presence of small dorsal and ventral parapodial cirri and pygidial features. External and internal anatomy was described after examination with SEM and micro-CT. The presence of several body structures in the genus such as a cephalic palpode-like papilla is discussed. Furthermore, the diversity of genus Polyophthalmus and the presence of Polyophthalmus pictus (Dujardin, 1839) in the Indo-Pacific is reviewed and a key to species is provided.

Detailed morphological study of more than 2600 North East Atlantic (NEA) sphaerodorids (Sphaerodoridae, Annelida) and phylogenetic analyses of DNA sequences of representatives of several identified morphospecies enforced changing the current systematic classification within the family, allowed the discovery of new species, provided new information about the morphological and genetic characterisation of members of this group, and increased the species occurrence data to better infer their geographic and bathymetric distribution ranges. Phylogenetic analyses of nuclear (18S rRNA and 28S rRNA) and mitochondrial sequences (COI and 16S rRNA) of NEA short-bodied sphaerodorids revealed outstanding results including paraphyly of the genera Sphaerodoropsis, Sphaerodoridium, and Sphaerephesia. The number of longitudinal and transverse rows of dorsal macrotubercles is proposed as potential synapomorphies for the main clades, and are consequently herein used for the genera delimitation. The new classification proposed here implies nomenclatural changes and the erection of a new genus, Geminofilum gen. n., to accommodate the species previously considered as Sphaerodoropsis with two transverse rows of dorsal macrotubercles per segment. Four species are being described herein: Euritmia nordica Capa & Bakken, sp. n., Sphaerephesia multichaeta Capa, Moreira & Parapar, sp. n., Sphaerephesia ponsi Capa, Parapar & Moreira, sp. n., and Sphaerodoridium celiae Moreira, Capa & Parapar, sp. n. Characterisation of the other 21 species, including updated iconography, and an identification key to all NEA short-bodied sphaerodorids are provided, Financial support was provided to MC by ForBio Research School, funded by the Research Council of Norway (project no. 248799) and the Norwegian Taxonomy Initiative (project no. 70184215) and by the Ramón y Cajal program (RYC-2016-20799) funded by the Spanish Ministerio de Economía, Industria y Competitividad, Agencia Estatal de Investigación, Comunidad Autónoma de las Islas Baleares and the European Social Fund. The Norwegian Taxonomy Initiative provided financial support to AN (knr 49-13, pnr 70184228), to TB (knr 53-09, pnr 70184216, knr 55-12, pnr 70184227); and by the Swedish Taxonomy Initiative [https://www.artdatabanken.se/en/the-swedish-taxonomy-initiative/] (dnr 140/07 1.4 and 166/08 1.4), to AN. Collections at MNCN and MNHN were visited by MC thanks to the European Commission Taxonomic Initiative SYNTHESYS (ES-TAF-2839, ES-TAF-7033, and FR-TAF-2644), SEM work was partially funded by Fauna Ibérica: Polychaeta VI (CGL2014-53332-C5-3-P). Publication fees were covered by NTNU Publishing Fund to MC

[Abstract]: Based on samples collected during the BIOICE project off Iceland, four species of marine annelids belonging to the family Pectinariidae were identified: “Amphictene auricoma” (O.F. Müller, 1776), “Cistenides granulate” (Linnaeus, 1767), “Cistenides hyperborean” Malmgren, 1865 and “Lagis koreni” Malmgren, 1866. Taxonomic remarks and data on geographical and bathymetric distribution are presented. The distribution of each species off Iceland was evaluated and two patterns were defined: “C. granulate” and “C. hyperborean” were mainly found in waters off the northeast coast, while “A. auricoma” and “L. koreni” were found on the southern coast. Several body characters with taxonomic value in this family were reviewed under the stereo microscope and scanning electron microscope, with special emphasis on the neuropodial uncini. Remarks on these special chaetae are included in the diagnoses. Ministerio de Ciencia, Innovación y Universidades; PGC2018-095851-B-C64

Zamora, José Luis, Parapar, Julio, Helgason, Gudmundur V., Moreira, Juan (2020): Taxonomy and distribution of Icelandic Fauveliopsidae (Annelida) collected during the BIOICE project. Journal of Natural History 53 (47-48): 2951-2974, DOI: 10.1080/00222933.2020.1757170, URL: http://dx.doi.org/10.1080/00222933.2020.1757170

The anatomy of Cossura pygodactylata Jones, 1956 (Annelida; Cossuridae) is presented, based on the study of specimens collected during the BIOICE project in Icelandic waters and additional material from the White Sea. General gross external and internal anatomy were investigated by means of micro-computed tomography (micro-CT) and compared with results obtained with light microscopy histological sectioning (LMHS). Micro-CT revealed a highly regionalised gut, posterior to the pharyngeal cavity and oesophagus, divided in an anterior stomach and a posterior intestine with different morphologies. The stomach is in the thoracic region, dorsally positioned and divided in a short and narrow anterior part and a longer posterior one, with an increasing diameter towards its posterior end. Both stomach regions bear a dorsal infolding of tissue, along its inner wall, that resembles to the typhlosole of the Clitellata. The heart is dorsally located and contains a heart body above the hind stomach. The intestine is wider than the stomach, without dorsal infolding inside the lumen and filling most part of the internal body cavity. A transitional cup-shaped gut element connecting the stomach and the intestine could be observed at the level of the last thoracic segment. In general, the resolution of micro-CT images reflects reasonably well the main elements of gross external and internal anatomy of cossurids, and that of gut architecture in particular.

The use of Micro-computed X-ray tomography (microCT or μCT) in the study of the anatomy of Annelids is becoming more common. Here we present a new approach to the anatomical study of six species (i.e. Phyllodoce lineata, Syllis garciai, Prionospio fallax, Branchiomma bombyx, Spirobranchus triqueter and Euclymene oerstedi) using μCT. These species represent several major annelid lineages and show therefore a wide range of morphological characteristics. Information obtained from μCT images of external and internal anatomy was compared with previous data with two major aims: 1) exploring whether quality of images allows accurate examination of annelid anatomy, and 2) evaluating the information provided by the different body characters, highlighting those with greater potential to be used for future biodiversity studies. Main conclusions obtained were: 1) the use of simple contrast staining or no staining at all provides good images that may be used in studies of comparative anatomy, 2) images of external anatomy show good definition only for macroscopic characters, 3) images of internal organs showed disparate results, being the digestive system the most promising structure, considering the quality of images and when assessing its regionalization and variability across taxa (genera, families).

Díaz-Díaz et al. (2018) described a new species of oweniid polychaete, Owenia vieitezi, from the north-western coast of the Gulf of Venezuela, Caribbean Sea. Although the description and figures presented by Díaz-Díaz et al. (2018) fully characterize the new species, the journal issue in which the description appeared was published online only and the article in which the new name appeared did not include a ZooBank registration number (LSID), required for validation of new species names in electronic-only publications (ICZN 2012). As a result, the name Owenia vieitezi Díaz-Díaz, Parapar & Moreira, 2018, as published in Cahiers de Biologie Marine 59: 589–597, is not available according the International Code of Zoological Nomenclature (ICZN 1999, 2012). Therefore, the present note serves to validate the name Owenia vieitezi by fulfilling the ICZN conditions for nomenclatural availability.

Ampharete oculicirrata sp. nov. (Annelida: Ampharetidae) is described from samples collected by the Joint Nature Conservation Committee and Marine Scotland Science, in the West Shetland Shelf NCMPA in the NE Atlantic. This species is characterised by a very small body size, thin and slender paleae, twelve thoracic and eleven abdominal uncinigers, presence of eyes both in the prostomium and the pygidium, the latter provided with a pair of long lateral cirri. The external micro-morphology of the new taxon was studied using scanning electron microscopy and compared with species described or reported from the North Atlantic. Two complementary keys to all species of Ampharete in the area are also provided, This study was partly supported by the research project ‘Fauna Ibérica: Polychaeta VI. Palpata. Canalipalpata I’ (CGL2014-53332-C5-3-P).

[Resumen] La Microtomografía Computarizada (micro-CT o μCT) es una técnica de estudio microestructural, no destructiva, que permite estudiar la anatomía interna y externa de muestras biológicas, y realizar su reconstrucción a través de un modelo virtual en tres dimensiones. En los últimos años esta técnica está aportando avances significativos en el conocimiento anatómico de diversos invertebrados marinos. En este trabajo se estudia la anatomía externa e interna de Laubieriopsis cabiochi (Amoureux, 1982) (Annelida, Fauveliopsidae) y paralelamente se valora la calidad de las imágenes de μCT frente a las obtenidas en estudios previos mediante métodos histológicos clásicos. [Abstract] Micro-computed tomography (micro-CT or μCT) is a microstructural, non-destructive, technique that allows the study of the external and internal anatomy of biological samples, and then allows for their reconstruction through 3D-virtual models. In the last years, this technique is providing significant advances in the knowledge of the anatomy of several marine invertebrate taxa. In this paper, we study the external and internal anatomy of Laubieriopsis cabiochi (Amoureux, 1982) (Annelida, Fauveliopsidae), comparing the quality of μCT images against those shown in previous works and obtained by classic histological methods. Ministerio de Economía y Competitividad; CGL2014-53332-C5-3-P

Background The overall anatomy of the genus Syllis (Annelida: Syllidae) has been largely studied; however, an integrative approach considering different anatomical techniques has never been considered. Here, we use micro-computed X-ray tomography (micro-CT) to examine the internal anatomy of Syllis gracilis Grube, 1840, along with other widely available techniques. Methods We studied the anatomy of the marine annelid S. gracilis through an integrative approach, including micro-CT along with stereo and light compound microscopy (STM, LCM), scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM) and histological sectioning (HIS). In this manner, we evaluated the applicability of micro-CT for the examination of annelid anatomy by testing whether the images obtained make it possible to visualize the main body structures, in comparison with other current techniques, of the various elements of its internal anatomy. Results Overall external and internal body elements are clearly shown by the integrative use of all techniques, thus overcoming the limitations of each when studied separately.Any given method shows disparate results, depending on the body part considered. For instance, micro-CT provided good images of the external anatomy, including relevant characters such as the shape, length and number of articles of dorsal parapodial cirri. However, it is especially useful for the examination of internal anatomy, thus allowing for 3D visualization of the natural spatial arrangement of the different organs. The features best visualized are those of higher tissue density (i.e., body musculature, anterior parts of the digestive tract), particularly in 3D images of unstained specimens, whereas less electrodense tissues (i.e., the peritoneal lining of septa and nervous system) are less clearly visualized. The use of iodine stain with micro-CT has shown advantages against non-staining for the adequate observation of delicate elements of low density, such as the segmental organs, the connective between the ganglia, the ventral nerve cord and segmental nerves. Discussion Main external anatomical elements of S. gracilis are well shown with micro-CT, but images show lesser optical resolution and contrast when compared to micrographs provided by SEM and CLSM, especially for fine structural features of chaetae. Comparison of micro-CT and HIS images revealed the utility and reliability of the former to show the presence, shape and spatial disposition of most internal body organs; the resolution of micro-CT images at a cellular level is, however, much lower than that of HIS, which makes both techniques complementary.

Background The overall anatomy of the genus Syllis (Annelida: Syllidae) has been largely studied; however, an integrative approach considering different anatomical techniques has never been considered. Here, we use micro-computed X-ray tomography (micro-CT) to examine the internal anatomy of Syllis gracilis Grube, 1840, along with other widely available techniques. Methods We studied the anatomy of the marine annelid S. gracilis through an integrative approach, including micro-CT along with stereo and light compound microscopy (STM, LCM), scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM) and histological sectioning (HIS). In this manner, we evaluated the applicability of micro-CT for the examination of annelid anatomy by testing whether the images obtained make it possible to visualize the main body structures, in comparison with other current techniques, of the various elements of its internal anatomy. Results Overall external and internal body elements are clearly shown by the integrative use of all techniques, thus overcoming the limitations of each when studied separately.Any given method shows disparate results, depending on the body part considered. For instance, micro-CT provided good images of the external anatomy, including relevant characters such as the shape, length and number of articles of dorsal parapodial cirri. However, it is especially useful for the examination of internal anatomy, thus allowing for 3D visualization of the natural spatial arrangement of the different organs. The features best visualized are those of higher tissue density (i.e., body musculature, anterior parts of the digestive tract), particularly in 3D images of unstained specimens, whereas less electrodense tissues (i.e., the peritoneal lining of septa and nervous system) are less clearly visualized. The use of iodine stain with micro-CT has shown advantages against non-staining for the adequate observation of delicate elements of low density, such as the segmental organs, the connective between the ganglia, the ventral nerve cord and segmental nerves. Discussion Main external anatomical elements of S. gracilis are well shown with micro-CT, but images show lesser optical resolution and contrast when compared to micrographs provided by SEM and CLSM, especially for fine structural features of chaetae. Comparison of micro-CT and HIS images revealed the utility and reliability of the former to show the presence, shape and spatial disposition of most internal body organs; the resolution of micro-CT images at a cellular level is, however, much lower than that of HIS, which makes both techniques complementary.

Regeneration, the ability to restore body parts after an injury or an amputation, is a widespread but highly variable and complex phenomenon in animals. While having fascinating scientists for centuries, fundamental questions about the cellular basis of animal regeneration as well as its evolutionary history remain largely unanswered. We study regeneration of the marine annelid Platynereis dumerilii, an emerging comparative developmental biology model, which, like many other annelids, displays important regenerative abilities. If the posterior part of the body is amputated, P. dumerilii worms are able to regenerate the posteriormost differentiated part of the body and stem cell-rich growth zone that allows to make new segments which replace the amputated ones. We show that posterior regeneration is a rapid process that follows a well reproducible paths and timeline, going through specific stages that we thoroughly defined. Wound healing is achieved by one day post-amputation and a regeneration blastema forms one day later. At this time point, some tissue specification already occurs, and a functional posterior growth zone is re-established as early as three days after amputation. Regeneration is only influenced in a minor manner by worm size and position of the amputation site along the antero-posterior axis of the worm and regenerative abilities persist upon repeated amputations without important alterations of the process. We also show that intense cell proliferation occurs during regeneration and that cell divisions are strictly required for regeneration to normally proceed. Finally, through several 5-ethynyl-2’-deoxyuridine (EdU) pulse and chase experiments, we provide evidence in favor of a local origin of the blastema, whose constituting cells mostly derive from the segment immediately abutting the amputation plane. The detailed characterization of P. dumerilii posterior body regeneration presented in this article provides the foundation for future mechanistic and comparative studies of regeneration in this species.

Based on specimens collected during several sampling programmes mainly in the northern North Sea, Scotland, a new species of the genus Terebellides (Polychaeta; Trichobranchidae) was found and described herein as Terebellides shetlandica spec. nov. The new species is primarily characterised by the presence of a long pointed posterior filament in the ventral branchial lobes. The species is compared with other Terebellides species described or reported from North Atlantic waters, and an updated key to the Terebellides species of the North East Atlantic and Mediterranean Sea is provided. The presence of copepods of the genus Melinnacheres attached to the thorax of this species is reported. Morphology of T. shetlandica spec. nov. was also studied with SEM and micro-CT. Branchial characters used in the taxonomy of the genus are reviewed and four general branchial types are defined.

We investigate mitochondrial (COI, 16S rDNA) and nuclear (ITS2, 28S rDNA) genetic structure of North East Atlantic lineages of Terebellides, a genus of sedentary annelids mainly inhabiting continental shelf and slope sediments. We demonstrate the presence of more than 25 species of which only seven are formally described. Species boundaries are determined with molecular data using a broad range of analytical methods. Many of the new species are common and wide spread, and the majority of the species are found in sympatry with several other species in the complex. Being one of the most regularly encountered annelid taxa in the North East Atlantic, it is more likely to find an undescribed species of Terebellides than a described one. © 2018 Nygren et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Terebellides stroemiiSars, 1835, the type species of the genus, was originally described from the south-west coast of Norway. Over the past 170 plus years this species has been reported from around the world often without a detailed description; in some cases, schematic illustrations of the anterior end with the distinctive branchiae were given. Identifications were likely based mainly on the branchiae consisting of 4–5 lobes but recent work has shown that this character alone has led to misidentifications and confusion of a number of morphologically similar species. Michael Sars (1835) did not designate type specimens for this species. In order to provide an accurate definition of the genus it is necessary to redescribe and characterize the type species including the designation of a neotype. This will provide a baseline against which the potentially undescribed sibling species in the area can be compared and fully described. A large collection of specimens identified asT. stroemiifrom locations along the coasts of Norway was studied in the Natural History Museum, University of Oslo. This has prompted us to locate material collected by M. Sars (1835) from the vicinity of the type locality and to designate a neotype and provide a comprehensive description of the type species of the genus.

During the Capbreton cruises (1987–1990), samples of bathyal benthic macrofauna were taken at 37 stations situated along the continental slope (480–1113 m depth) of the Capbreton Canyon (Bay of Biscay, north-east Atlantic). Ten species of polychaetes belonging to six genera (Melinna, Eclysippe, Amphicteis,Anobothrus, GlyphanostomumandTanseimaruana) of the family Ampharetidae Malmgren, 1866 were collected at 13 of these stations. Most of these species are reported for the first time in the area.Amphicteisaff.wesenbergaeis reported for the first time after its recent description and a new species belonging to the genusGlyphanostomumis here described. Moreover, the finding ofMelinna monoceroidesrepresents the northernmost record of the species;Tanseimaruana vestisis recorded for the second time from the East Atlantic after its recent finding in Icelandic waters;Anobothrusaff.gracilisis reported for the second time from the Iberian Peninsula, representing, the southernmost record of the species in the Atlantic Ocean. The potential identification of two fragments of an Ampharetinae indet asAnobothrus laubieri, a deep water Arctic species, is discussed.

[Abstract] The present paper reports on some morphological and biological features of the scale-worm Laetmonice producta producta Grube, 1877 (Polychaeta: Aphroditidae) in the northwestern sector of Antarctica. A total of 114 specimens were collected during the 2003 and 2006 cruises of the BENTART project on the shelf and upper slope of the Antarctic Peninsula and the Bellingshausen Sea. Specimens were collected using an Agassiz trawl at 22 stations covering a depth ranging from 115 to 1431 m. Bathymetric distribution, abundance and sizes, diet, presence of endosymbionts and epibionts, and some observations related to parapodial structure and chaetal types are discussed in relation to taxonomy and environmental characteristics and compared to previous data. Ministerio de Ciencia y Tecnología; REN2001-1074/ANT Ministerio de Ciencia y Tecnología; CGL2004-01856

Knowledge about the taxonomy and distribution of the monogeneric polychaete family Longosomatidae Hartman, 1944 is limited in all parts of the world. A new species of the genus Heterospio Ehlers, 1874 (Annelida, Longosomatidae) is described from the Indian Ocean. Heterospio indica sp. nov. is mainly characterised by the conspicuous fl attening of the distal half of capillary chaetae located in anterior elongated segments. Several body characters of high taxonomic relevance in the genus are examined under the SEM and discussed. The 18S SSU rDNA and COI genes were sequenced and represent the fi rst sequencing of a species of Heterospio, and the sequences have been deposited in GenBank Ministerio de Economía y Competitividad; CGL2014-53332-C5-3-P

28 páginas, 8 figuras, 2 tablas., The study of material collected during routine monitoring surveys dealing with oil extraction and aquaculture in waters off Myanmar (North Andaman Sea) and in the Gulf of Thailand, respectively, allowed us to analyse the taxonomy and diversity of the polychaete genus Terebellides (Annelida). Three species were found, namely Terebellides cf. woolawa, Terebellides hutchingsae spec. nov. (a new species fully described and illustrated), and Terebellides sp. (likely a new species, but with only one available specimen). The new species is characterised by the combination of some branchial (number, fusion and relative length of lobes and papillation of lamellae), and thoracic (lateral lobes and relative length of notopodia) characters and is compared with all species described or reported in the SW Indo-Pacific area, as well as with those sharing similar morphological characteristics all around the world. The taxonomic relevance of the relative length of branchial lobes and different types of ciliature in branchial lamellae for species discrimination in the genus is discussed. A key to all Terebellides species described in SE Indo-Pacific waters is presented., The study has been financed by the research projects ``Fauna Ibérica: Polychaeta VI: Palpata, Canalipalpata I'' (CGL2014-53332-C5-3-P) and ``MarSymBiomics'' (CTM2013-43287-P), funded by the Ministerio de Economía y Competitividad of Spain, as well as by the Consolidated Research Group on Marine Benthic Ecology (2014SGR120), funded by the Generalitat de Catalunya, and the research contract between the CEAB (CSIC) and the French company Créocéan.

Based on specimens collected during several sampling programmes along the Iranian coast, Persian Gulf, a new species of the genus Terebellides (Polychaeta, Trichobranchidae) is herein described as Terebellides persiae spec. nov. The new species is primarily characterised by the presence of a large dorsal thoracic hump in larger specimens and ciliated papillae on the branchial lamellae. The new species is compared with other taxa belonging to Terebellides described or reported with any of both characters. SEM and micro-CT have been used to study T. persiae spec. nov. and provide several new details on external characters and internal organs, respectively. A key for the identification of the species of Terebellides with dorsal hump is provided.

The family Oweniidae Rioja, 1917 is a small group of broadly distributed polychaetes whose relationships and position in the annelid tree are still poorly understood. A comprehensive revision of the group with reconsideration of character homologies and terminology under a phylogenetic framework was needed. We investigated the relationships of members of Oweniidae and other polychaetes by performing maximum parsimony analyses of 18 oweniid species of the five recognized genera to date and members of the families Siboglinidae, Sabellidae, Spionidae, Magelonidae, and Chaetopteridae. Phylogenetic hypotheses confirmed the monophyly of Oweniidae and suggested sister-group relationships with Magelonidae, although weakly supported. Analyses also recovered Owenia and Myriowenia as monophyletic and allowed recognition of Myrioglobula as a junior synonym of Myriochele based on the presence of acicular chaetae and the shape of the head. Implied weighting analyses supported these findings and recovered Galathowenia australis as sister group of Myriochele. The presence of acicular chaetae justifies the consideration of this species as belonging to Myriochele. Nomenclatural changes are proposed for those species previously considered as members of Myrioglobula, and these are: Myriochele antarcticacomb. nov., Myriochele japonicacomb. nov., Myriochele islandicacomb. nov., Myriochele malmgrenicomb. nov., and Myriochele australiscomb. nov. After analyses and definition of generic diagnostic features, other new combinations include Galathowenia eurystomacomb. nov. and Galathowenia haplosomacomb. nov., previously considered as members of Myriochele. Taxonomic revision of Australian collections revealed the presence of Myriochele heruensis Gibbs, 1971, which is herein redescribed, and allowed the description of four new species: Galathowenia annae sp. nov., Galathowenia arafurensissp. nov., Galathowenia quelissp. nov., and Myriochele australiensissp. nov., mostly from the east coast of Australia, in addition to the three recently well-documented species of Owenia. Australian species have been described, illustrated, and compared in detail with similar taxa. Distribution patterns and ecological notes have also been given. Keys to oweniid genera and Australian species are provided. © 2012 The Linnean Society of London, Zoological Journal of the Linnean Society, 2012, 166, 236–278.

Based on material collected during the BIOICE project off Iceland, the taxonomy and distribution of eight species of polychaetous annelids belonging to the genus Ampharete (Polychaeta: Ampharetidae) are reviewed. Five of these species were previously reported in the area: Ampharete acutifrons, Ampharete borealis, Ampharete finmarchica, Ampharete octocirrata and Ampharete petersenae; two are new to Icelandic waters: Ampharete baltica and Ampharete lindstroemi; and one is new to science: Ampharete villenai sp. nov. A. petersenae was found for the first time after the original description and is redescribed. A. villenai sp. nov. is primarily characterized by the size, shape and disposition of the paleae, a special kind of chaetae located on the first body chaetiger. Several body characters of high taxonomic relevance in Ampharetidae are reviewed under the SEM. The distribution of each species off the coast of Iceland and a key to all species recorded in European Boreo-Arctic waters is provided.

[Abstract] The deep-sea genus Axiokebuita (Annelida, Scalibregmatidae) has hitherto been considered to contain two species, Axiokebuita minuta (Hartman, 1967) and Axiokebuita millsi Pocklington and Fournier, 1987, each rarely recorded in the literature and both supposedly having bipolar distributions. From the study of some types, other museum collection material, plus newly collected specimens from the slope depths of the Bellingshausen Sea and off the Antarctic Peninsula (Antarctica), Iceland and Iberian Peninsula, as well as from hydrothermal vents of the southeastern Pacific Ocean, the taxonomic history of the genus is revisited. Based on the results of this study, the features traditionally used to distinguish between the two species are actually the same in both. Therefore, A. millsi is proposed to be synonymised with A. minuta, which is redescribed and considered the only valid species of the genus, leaving Axiokebuita monotypic. Two previously unnoticed body sensory structures, i.e. a ciliated neck organ and a prostomial depression, were observed under scanning electron microscopy. United States. National Science Foundation; OCE- 0241613 United States. National Science Foundation; OCE-0350554 Ministerio de Educación y Ciencia; GLC2004–01856/ANT

Based on material collected during the BIOICE project off Iceland, four species of polychaetous annelids belonging to the genus Amphicteis Grube, 1850 (Polychaeta: Ampharetidae) were found: Amphicteis gunneri, Amphicteis ninonae, Amphicteis vestis and Amphicteis wesenbergae sp. nov. The differences between A. gunneriand A. ninonae, two species usually confused in the literature, are reviewed. Amphicteis vestis is described from newly collected material and its taxonomy in relation to other ampharetid taxa with modified notopodia is discussed. Amphicteis wesenbergae sp. nov. is described; the new species is characterized by the presence of long, slender and evenly tapered paleae, and long dorsal cirri on thoracic and abdominal neuropodia. Several body characters with high value in Amphicteis taxonomy, particularly the dorsolateral protrusions of abdominal chaetigers called rudimentary notopodia, are reviewed using scanning electron microscopy. A key to species of the genus Amphicteis described or reported in European Boreo-Arctic waters is provided. European Commission; DK-TAF-3118 European Commission; SE-TAF-4599

El conocimiento sobre los Sphaerodoridae (Annelida, Polychaeta) es todavia insuficiente en muchas partes del planeta, incluyendo los fondos del sistema marino profundo de la peninsula Iberica. El estudio de las muestras recogidas entre 100 y 2000 m de profundidad durante varias campanas oceanograficas en el Margen Continental de Galicia (NW peninsula Iberica) entre 2003 y 2009 ha mostrado la presencia de seis especies de poliquetos pertenecientes a la familia Sphaerodoridae. Dos de estas especies son mencionadas por primera vez desde su descripcion original: Sphaerodoropsis sibuetae Desbruyeres, 1980 y S. amoureuxi Aguirrezabalaga & Ceberio, 2005; estos registros extienden la distribucion conocida de ambas especies hacia el Oeste en el Oceano Atlantico. Asimismo, se mencionan todas las especies encontradas aportando datos sobre su distribucion y ecologia, y se incluye una clave con todas las especies conocidas de la peninsula Iberica.

The structure and spatial distribution of the macrofauna community of the Bellingshausen Sea in the western sector of Antarctica was studied during the ‘BENTART–06’ oceanographic expedition. This is one of the least explored Antarctic seas. A total of 20 box cores were sampled at 11 stations ranging from 157 to 3,304 m depth, using an USNEL-type box corer (BC) dredge. Representatives of 25 higher taxa of invertebrates were collected. Deeper sampling sites were less rich in taxa (4–7 taxa), whereas the figures were higher at shallower sites (up to 17 taxa). Faunal density on the sea bottom revealed a horizontal spatial gradient from the western sites with extremely low figures (90 indiv./m2) towards the eastern ones with the highest figures (1,360 indiv./m2) close to the Antarctic Peninsula. Several abiotic factors (depth, redox, organic matter, carbonates and particle size of surficial sediments) were measured simultaneously on the sea floor to characterise the substrate preferences of the fauna. Positive correlations were found between the faunal distribution and a combination of depth, redox values, and organic matter content of sediments. This indicates decreasing availability of food in the deeper bottoms of the Bellingshausen Sea with a prevalence of depauperated bottoms dominated almost exclusively by a foraminiferans community., Sí

A new species of Synelmis (Annelida: Polychaeta: Pilargidae), Synelmis urgorrii sp. nov., is described from the continental slope off north-western Spain. The new species is characterized by having antennae, peristomial cirri and parapodial cirri cirriform, lateral antennae located in the proximal third of the prostomium, notospines starting on chaetigers 7–11, well-developed neuropodial lobe and asymmetrical furcate chaetae, those of anterior chaetigers distinctly spinulated.

From the study of the material collected during the Polychaete Workshop held in Lizard Island (Great Barrier Reef, Australia) in August 2013, six species belonging to the genus Armandia (Polychaeta, Opheliidae) are newly described. Armandia bifida n. sp. is characterised by the bifid shape of the prechaetal lobe in CH1-CH3, A. dolio n. sp. by the barrel-shaped anal (=pygidial) tube (=funnel), A. filibranchia n. sp. by the extremely long and thin branchiae, A. laminosa n. sp. by the foliose shape and large size of the prechaetal lobe in CH1-CH3, A. paraintermedia n. sp. by the squared-shaped anal tube and size and shape of anal cirri, and A. tubulata n. sp. by the tubular shape of the anal tube. All species are fully described and illustrated, and compared with similar species. Several body characters of taxonomic relevance (e.g., anal tube and parapodia shape) are studied based on SEM micrographs. A key of the Armandia species hitherto described or reported in South-East Asia and Australasia is provided based on features of the anal tube.

Study of the Oweniidae specimens (Annelida; Polychaeta) from Lizard Island (Great Barrier Reef, Australia) stored at the Australian Museum, Sydney and newly collected in August 2013 revealed the presence of three species, namely Galathowenia quelis Capa et al., 2012 and two new species belonging to the genus Owenia Delle Chiaje, 1844. Owenia dichotoma n. sp. is characterised by a very short branchial crown of about 1/3 of thoracic length which bears short, dichotomously-branched tentacles provided with the major division close to the base of the crown. Owenia picta n. sp. is characterised by a long branchial crown of about 4/5 of thoracic length provided with no major divisions, ventral pigmentation on thorax and the presence of deep ventro-lateral groove on the first thoracic chaetiger. A key of Owenia species hitherto described or reported in South East Asia and Australasia regions is provided based on characters of the branchial crown.

A new species of the genus Orbiniella Day, 1954 (Polychaeta: Orbiniidae), collected during the BIOICE programme on sedimentary bottoms off Iceland, is described. Orbiniella petersenae sp. nov. is a shelf and slope species (107 to 1,915 m) chiefly characterized by having notopodial postchaetal papilla from first chaetiger, long crenulated capillary chaetae and several acicular chaetae on each parapodial rami, and pygidium with four lobes. External micromorphology and gross internal anatomy were studied using, respectively, SEM and micro-CT; this is the first time these techniques are used for any species in this genus. A key to all species of this genus worldwide is provided.

Based on material collected during the BIOICE project off Iceland, the taxonomy and distribution of six species of polychaetous annelids belonging to the family Oweniidae are reviewed. Three species were previously reported in the area: Owenia fusiformis Delle Chiaje, Myriochele heeri Malmgren and Galathowenia oculata (Zaks); two are new to Icelandic waters: G. fragilis (Nilsen & Holthe) and Myriochele danielsseni Hansen, and one is new to science: Myrioglobula islandica, which is described and compared with Myrioglobula antarctica Hartman and Myrioglobula japonica Imajima & Morita. Several body characters with a high taxonomic value in oweniids were reviewed under the scanning electron microscope. In G. fragilis, the presence of an anteroventral structure, possibly related to tube construction, is presented, as well as its original description, proposed to be emended, due to the confirmation of a hook-shaped variability over the length of the body. The distribution of each species off Iceland was evaluated and two patterns were defined: O. cf. fusiformis and G. oculata were mainly found in sublittoral (

Among the benthic lithological samples collected during the Spanish Antarctic survey GEBRAP 1996–97 in the Bransfield Strait, two new oweniid (Annelida, Polychaeta, Oweniidae) species were collected: Myriochele riojai n. sp. and Myriochele robusta n. sp. Myriochele riojai is closely related to M. heeri Malmgren, 1867 but differs in body size, number and distribution of the notosetae and in the position of elongated abdominal body segments. Myriochele robusta differs from all known species of the genus owing to its possession of a biramous setiger between two uniramous setigers in the anterior (thoracic) body region. A key to oweniid species recorded in Antarctic waters is provided.