Karin Meißner

Spionidae (Annelida: ‘Polychaeta’: Canalipalpata) from Lizard Island, Great Barrier Reef, Australia: the genera Malacoceros , Scolelepis , Spio , Microspio , and Spiophanes

Seven species belonging to the spionid genera Malacoceros, Scolelepis, Spio, Microspio, and Spiophanes were found during the polychaete workshop on Lizard Island in August 2013. One species is new to science and named Scolelepis inversa n. sp., another Scolelepis species is probably also a new species but was represented in our samples by only a single specimen and not formally described. All other species have been reported previously from Australia. Species diagnoses of all species found during the workshop and of Scolelepis balihaiensis Hartmann-Schröder, 1979, Microspio microcera (Dorsey, 1977) and M. minuta (Hartmann-Schröder, 1962) have been critically reviewed and amended based on the study of type material. The potential synonymy of Microspio minuta (Hartmann-Schröder, 1962) and M. microcera (Dorsey, 1977) is discussed. The new combination Spio jirkovi (Sikorski, 1992) proposed by Sikorski (2013) is returned to Malacoceros. We added DNA barcodes for five species collected in the Lizard Island area to public databases which will be useful in future phylogenetic and phylogeographic studies. For Microspio we provide the first sequence data for this genus.

Histological and ultrastructural reconstruction of ventral epidermal glands of Spio (Polychaeta, Spionidae, Annelida)

With present study, we confirm that the ventral structures on anterior and middle chaetigers of two species of Spio are special kind of intraepidermal multicellular glands. The general anatomy and coherence morphology of these ventral epidermal glands (VEGs) were 3D-reconstructed based on semithin section series. Specific anatomical characters were explored using electron microscopy, such as scanning electron microscopy for characterization of gland pores and transmission electron microscopy for investigation into cytoanatomical details. The VEGs are tubular or acinar; their pores are spherical or lens-shaped. The glands consist of three cell types: secretory cells, sheath cells and canal cells, forming and strengthening the short gland duct and the pore region. The secretory cells are tightly packed into a single-layered, curved glandular epithelium. Secretory cells are separated from each other by thin projections of interstitial sheath cells. The apices of the secretory and sheath cells surround a tubular or vase-shaped extracellular space, the reservoir. The reservoir is traversed by microvilli of the secretory and sheath cells. Two sorts of microvilli characterize the apex of secretory cells: slender, elongated ones located at the periphery (outer microvilli), and shorter but thicker ones, arranged in a distinct collar in the centre (inner microvilli). Secretion, encased in regular secretory granules and discharged only at the apex’ centre, is guided through the space enclosed by the collar of inner microvilli. Though also consisting of numerous cells, the VEGs of Spio spp. are not comparable to parapodial glands described in other spionid taxa since they remain in a strictly intraepidermal position, are distant from parapodia and contain sheath cells. Nonetheless, the VEGs are very helpful for taxonomic work on representatives of the genus Spio and closely related genera.

A contribution to the taxonomy of Spio (Spionidae, Polychaeta, Annelida) occurring in the North and Baltic Seas, with a key to species recorded in this area

In order to resolve taxonomic problems known from literature and diagnostic practices, Spio species currently recognised in the North Sea and the Baltic Sea have been re-examined. Spio species recorded in the area of interest are S. decoratus, Spio cf. filicornis, S. goniocephala, S. martinensis, and S. armata. Spio decoratus is restricted to the North Sea, whereas S. armata occurs only in the Baltic Sea. Revised descriptions with illustrations and notes on the distributions, as well as remarks on size-dependent differences of characters, are presented for all species. Specimens of Spio from the North and Baltic Seas, which are assigned to S. filicornis based on current taxonomic literature, exhibit significant morphological differences, and are here regarded as two different species. A definite assignment of specimens from the two morphological distinct groups to one of the known Spio species was impossible based on the material available. The significance of diagnostic characters used for the identification of Spio spp. is discussed. An identification key to Spio species found in the investigation area is provided.

Redescription of P. dorsipapillatus (von Marenzeller, 1893) and additional comments on the other species in the genus Pholoides Pruvot, 1895 (Polychaeta: Sigalionidae)

Pholoides Pruvot, 1895 is a species-poor genus of small scale-bearing polychaetes. Pholoides species are restricted to the continental shelf, living in sandy and muddy substrates, or on hard bottoms. During the DIVA 3 expedition grab samples were taken on four seamounts of the Meteor Seamount complex. One of the most common polychaetes in these samples was P. dorsipapillatus (von Marenzeller, 1893). Based on this material a comparison with the type material is undertaken leading to a re-description of P. dorsipapillatus. Diagnostic characters of all accepted Pholoides species were evaluated using light, scanning electron and confocal laser scanning microscopy. CLSM in particular proved to be an excellent tool for investigating these small species, and especially the type material. Blossom-like sensory buds, found at certain appendages of P. dorsipapillatus, could be an important diagnostic character to distinguish P. dorsipapillatus from other Pholoides species. Sequence information on three different gene fragments, the mitochondrial COI and 16S and the nuclear H3a, were obtained, and could serve for future phylogenetic and phylogeographic studies.

Description of a new species of Sabellidae (Polychaeta, Annelida) from fresh and brackish waters in Europe, with some remarks on the branchial crown of Laonome

In 2009, a hitherto unknown Laonome species was found in the Canal Ghent-Terneuzen in the Netherlands and subsequently in other Dutch rivers, canals and estuaries. A few years later, more unknown Laonome specimens were found in the eastern part of the Baltic Sea and in the Don River estuary, Sea of Azov. Initially, it was assumed that these specimens could represent Laonome calida Capa, 2007, originally described from Australia. In the present study we examine all these unknown European Laonome specimens and compare these specimens with the type material of L. calida from Australia. This lead to two main results: First, all specimens from Europe have the same diagnostic characters and therefore belong to one species. This finding was also supported by the results of a correspondence analysis, and genetic analyses using four different DNA sequences (COI, 16S, 28S). Second, it turned out that the type material of L. calida contains two morphologically distinct groups of specimens. The holotype and 7 paratypes are similar to each other but differ significantly from the other also similar 16 paratypes, and from all European specimens. On the basis of these observations, the Laonome specimens from European waters are described here as L. xeprovala sp. nov. We also provide the characters of the branchial crown of three Laonome species for a prospective revision of this genus.

Preface—biodiversity of Icelandic waters

This special issue focuses on the biodiversity of Icelandic waters and on the outcome of the IceAGE (Icelandic Animals: Genetics and Ecology) project. It presents international efforts to deepen our understanding of deep-water ecosystems and biodiversity patterns found in the region. The IceAGE project is a successor of BIOFAR and BIOICE studies that explored the biodiversity found on the continental shelves around the Faroe Islands and Iceland, respectively. In contrast, IceAGE is exploring the diversity of animals that live on the deep continental slope and in abyssal waters around Iceland. Information on the development of the IceAGE project, the geologic setting, and other scientific background is provided in detail in Brix et al. (2014a). Although the project encompasses basic questions about deep-sea biodiversity and correlation between genetic, morphological, and environmental patterns, several larger issues are central to the project. Namely, deep waters around Iceland include boreal, subarctic, and Arctic zones that hold discrete bodies of water. This allows for comparative studies of deep-sea ecosystems. How much variation exists between basins in the deep sea? Is there gene flow between deep-sea basins? Do we see the same patterns in the deep sea and the continental shelf? Importantly, the IceAGE project and its predecessors, BIOFAR and BIOICE, offer unprecedented baseline data for twomajor societal issues facing current and future generations. One is the impact of climate change on the deep sea. The northern Atlantic region around Iceland has long been known to be a critical region for regulation of the global thermohaline circulation. Recent reports have shown that human-mediated global climate change is already producing measurable changes in the circulation patterns in this region (Jochumsen et al. 2016). One of these largest changes concerns the formation of cold deep water (Lohmann and Gerdes 1998; Meehl et al. 2007; Winton 1997). With the loss of Arctic sea ice deepwater formation has slowed, presumably impacting the flow and chemistry moving along the study region. The second societal issue is deep-sea mining. There has been growing international interest in deep-sea resource extraction and mining operations are about to begin in some areas (Halfar and Fujita 2007; Mengerink et al. 2014; Nagender Nath and Sharma 2000). These operations, in particular, are targeting mid-ocean ridges and other geothermally active areas. The ridges around Iceland include such areas, e.g., the Reykjanes Ridge with hydrothermal vent sites. The extent of damage and loss of ecosystem services caused by mining activities cannot be adequately evaluated without baseline data. This special issue embedded in a topical collection of articles presents international efforts to collect and analyze biodiversity from the region that can enhance our understanding of deep-water ecosystems around Iceland. From the beginning in 2011, the IceAGE project relied on an international group of scientists who pursued the pre-determined objectives. One of the main tasks was the geoand time-referenced collection of marine invertebrates together with information on environmental parameters from different habitats around Iceland. In contrast to earlier projects, sampling was extended to deep waters north and south of Iceland, and specimens were no longer exclusively fixed in formalin but also in 96% ethanol. This allowed the use of a larger range of methods, as for example molecular methods (Riehl et al. 2014) in addition to various classical methods. This article is part of the Topical Collection on Biodiversity of Icelandic Waters by Karin Meißner, Saskia Brix, Ken M. Halanych and Anna Jazdzewska.

Diversity and phylogenetic relationships of North Atlantic Laonice Malmgren, 1867 (Spionidae, Annelida) including the description of a novel species

Spionid polychaetes are dominant members of many marine soft-bottom communities. As such, understanding their diversity and evolutionary history is of general interest. One spionid group in particular, Laonice, is known from the North Atlantic with several species occurring in deeper waters. We explored, as part of the IceAGE project, the biodiversity and evolution of Laonice using both morphology and mitochondrial cytochrome c oxidase subunit I (COI) gene data. Our data confirm the existence of at least seven lineages of Laonice in waters surrounding Iceland. Additionally, our sampling suggests species distributions of Laonice are similar to previous reports for other annelids, in that warmer waters south of Iceland appear to harbor more species, but further work is needed to clarify distribution patterns. Although our analysis was hampered by quality of preservation of animals from deep water, we recovered several species that were previously known to science (e.g., Laonice blakei, Laonice sarsi, Laonice cf. norgensis, and Laonice cirrata) and one new species. Laonice plumisetosa sp. nov. is characterized by having u-shaped nuchal organs not exceeding chaetiger 1 and the presence of stout capillaries with plush-like texture in parapodia of anterior chaetigers. Uncorrected genetic distances and phylogenetic analyses of COI data confirm these Laonice lineages are distinct. However, L. cirrata is composed of three subclades suggesting unrecognized diversity within this species. In the present paper, we aim to provide a preliminary phylogeny for Laonice and discuss our results in relation to the recently proposed subgenera for Laonice.

New records of Spio symphyta and Spio martinensis (‘Polychaeta’: Canalipalpata: Spionidae) from Arcachon Bay (France), NE Atlantic

This paper presents new records of Spio symphyta Meißner et al., 2011 and Spio martinensis Mesnil, 1896 (‘Polychaeta’: Canalipalpata: Spionidae) from Arcachon Bay (southern Bay of Biscay). For both species the new records represent an extension of their known distributional range. The two species have probably been present in Arcachon Bay for several years but were confused with other species of the genus Spio. Spio symphyta was identified at five locations in Arcachon Bay in 2009 and 2013 and S. martinensis at three stations in 2012 and 2013. A detailed and illustrated description of specimens from Arcachon Bay is provided. Important characters of Spio spp. occurring in the area are compared.