Jaw morphology and function in Drilonereis cf. filum (Oenonidae, Annelida).

Representatives of the extant family Oenonidae (Annelida, Eunicida) have a prionognath jaw apparatus, with maxillae having forceps-like elements, a number of asymmetrical dentate plates and long slender carriers, which is characteristic of some fossil forms known from the Paleozoic epoch. Therefore, data on the fine structure and functional morphology of Oenonidae jaws are helpful for the interpretation of fossil materials. The fine structure of the jaw apparatus and the ventral pharyngeal organ is studied in one species of the Oenonidae (Annelida)-Drilonereis cf. filum. The material was collected in the soft bottom of Marseille Bay (Mediterranean) and examined with the help of TEM and histological techniques. A three-dimensional (3D) reconstruction was made from a complete series of semithin sections. The entire jaw apparatus is about 500 µm in length; it includes ventral mandibles and four pairs of maxillae, connected with long paired dorsal carriers and an unpaired ventral carrier. While retracted, it reaches the VIII-XI chaetigers. The most solid part of the maxillary apparatus, that is, maxillae I and II, are 2.5-5 µm thick. The plate consists of a monolithic array of merged scleroprotein granules in which perforations, that is, spaces remaining from microvilli, are visible; the basal part of the maxillary plate is a layer of loosely arranged collagen fibers penetrated with microvilli and has no signs of sclerotization. A study of the jaws of Drilonereis cf. filum showed the presence of common jaw patterns in Eunicida order. Like the jaws of Dorvilleidae, Eunicidae, Onuphidae, and Lumbrineridae, the jaws of Drilonereis are formed at the basis of a typical annelid cuticle's transformation with epi- and basicuticular layers, and its impregnation by merging scleroprotein granules. Through the nature of sclerotization, the jaws of D. cf. filum are similar to those of Dorvilleidae, Histriobdellidae, and the juvenile jaws of Mooreonuphis stigmatis (Onuphidae). Analysis of the 3D-reconstructions of the D. cf. filum jaw apparatus shows that the MxI of this species, and probably of other Oenonidae with dorsal and ventral carriers, can make grasping motions by fixing the joint of the right and left MxI in the two-door hinge type. In general, the overall structure of the jaw apparatus of D. cf. filum and the mechanics of its work shows greater similarity with that of Dorvilleidae than with the jaw apparatus of extant Labidognatha and Simmetrognatha (Onuphidae, Eunicidae, Lumbrineridae). The need for compactization of the jaw apparatus when moving in dense sediment or in the burrows is probably one of the factors determining its structure.

Annelids of the eastern Australian abyss collected by the 2017 RV 'Investigator' voyage.

In Australia, the deep-water (bathyal and abyssal) benthic invertebrate fauna is poorly known in comparison with that of shallow (subtidal and shelf) habitats. Benthic fauna from the deep eastern Australian margin was sampled systematically for the first time during 2017 RV 'Investigator' voyage 'Sampling the Abyss'. Box core, Brenke sledge, and beam trawl samples were collected at one-degree intervals from Tasmania, 42°S, to southern Queensland, 24°S, from 900 to 4800 m depth. Annelids collected were identified by taxonomic experts on individual families around the world. A complete list of all identified species is presented, accompanied with brief morphological diagnoses, taxonomic remarks, and colour images. A total of more than 6000 annelid specimens consisting of 50 families (47 Polychaeta, one Echiura, two Sipuncula) and 214 species were recovered. Twenty-seven species were given valid names, 45 were assigned the qualifier cf., 87 the qualifier sp., and 55 species were considered new to science. Geographical ranges of 16 morphospecies extended along the eastern Australian margin to the Great Australian Bight, South Australia; however, these ranges need to be confirmed with genetic data. This work providing critical baseline biodiversity data on an important group of benthic invertebrates from a virtually unknown region of the world's ocean will act as a springboard for future taxonomic and biogeographic studies in the area.

Microbial associations of shallow-water Mediterranean marine cave Solenogastres (Mollusca).

The first cave-dwelling Solenogastres-marine shell-less worm-like mollusks-were sampled from Mediterranean marine caves floor silt in the Marseille area. The mollusks were 1.5 mm in length, had a transparent body with shiny spicules and appear to represent a new Tegulaherpia species. Electron microscopy revealed a high number of microbial cells, located on the surface of the spicules as well as in the cuticle of Tegulaherpia sp. The observed microbial cells varied in morphology and were unequally distributed through the cuticle, reaching a highest density on the dorsal and lateral sides and being practically absent on the ventral side. Next Generation Sequencing (NGS) of V4 region of 16S rRNA gene amplicons, obtained from the DNA samples of whole bodies of Tegulaherpia sp. revealed three dominating microorganisms, two of which were bacteria of Bacteroidetes and Nitrospirae phyla, while the third one represented archaea of Thaumarchaeota phylum. The Operational Taxonomic Unit (OTU), affiliated with Bacteroidetes was an uncultured bacteria of the family Saprospiraceae (93-95% of Bacteroidetes and 25-44% of the total community, depending on sample), OTU, affiliated with Nitrospirae belonged to the genus Nitrospira (8-30% of the community), while the thaumarchaeal OTU was classified as Candidatus Nitrosopumilus (11-15% of the community). Members of these three microbial taxa are known to form associations with various marine animals such as sponges or snails where they contribute to nitrogen metabolism or the decomposition of biopolymers. A similar role is assumed to be played by the microorganisms associated with Tegulaherpia sp.

Review of Orbiniidae (Annelida, Sedentaria) from Australia.

The present study is a review of all known Australian and New Zealand orbiniid species with their redescription based mainly on the collection of the Australian Museum (Sydney). A total of 28 species were examined: seven species of Scoloplos, three species of Leitoscoloplos, five species of Leodamas, three species of Naineris, two species of Orbinia, three species of Phylo, one species of Proscoloplos, and four species of Protoariciella. Leodamas australiensis (Hartmann-Schröder, 1979) is the new combination. Illustrated descriptions and an identification key for Australian and New Zealand orbiniids are provided.

Revision of Fauveliopsidae Hartman, 1971 (Annelida, Sedentaria).

Abyssal polychaetes are usually difficult to be identified because they are small, their body patterns differ from their shallow water relatives, their delicate bodies are often damaged during sampling and sieving, and their taxonomy is in need of revision. Members of the family Fauveliopsidae Hartman, 1971 are widespread in deep ocean basins and they follow the above statements. In this contribution, we present a revision of all available type and non-type material for the family. Our objective is to provide keys to identify genera and species, as well as standardized diagnoses, and illustrations for most species, excluding those described since 2011, or where type material was not available. One genus, Riseriopsis n. gen., is proposed and four species are newly described. The Fauveliopsidae now includes 24 species in three genera: Fauveliopsis McIntosh, 1922 (13 species), Laubieriopsis Petersen, 2000 (8 species), and Riseriopsis n. gen. (3 species). Fauveliopsis includes species usually living inside gastropod or scaphopod shells or foraminiferan tubes, Laubieriopsis and Riseriopsis include species commonly regarded as free living, although some species of the latter have very long bodies and have been found inside soft tubes. Fauveliopsis includes: F. adriatica Katzmann Laubier, 1974, F. armata Fauchald Hancock, 1981, F. brattegardi Fauchald, 1972a, F. brevipodus Hartman, 1971, F. challengeriae McIntosh, 1922, F. glabra (Hartman in Hartman Barnard, 1960), F. jameoaquensis Núñez in Núñez, Ocaña Brito, 1997, F. levensteinae n. sp., F. magalhaesi n. sp., F. magna Fauchald Hancock, 1981, F. olgae Hartmann-Schröder, 1983, F. rugosa Fauchald, 1972b, and F. scabra Hartman Fauchald, 1971. Laubieriopsis includes: L. arenicola (Riser, 1987), L. blakei n. sp., L. brevis (Hartman, 1965), L. cabiochi (Amoureux, 1982), L. fauchaldi (Katzmann Laubier, 1974) n. comb., L. hartmanae (Levenstein, 1970) reinst., L. norvegica Zhadan Atroshchenko, 2012, and L. petersenae Magalhães, Bailey-Brock Rizzo, 2014. Riseriopsis includes: R. arabica (Hartman, 1976) n. comb., R. confusa (Thiel, Purschke Böggemann, 2011) n. comb., and R. santosae n. sp. Keywords. Deep-sea species, taxonomy, genital papillae, genera, species  Introduction The family-group name Fauveliopsidae was established by Hartman (1971) and derived from Fauveliopsis McIntosh, 1922. The genus-group name was dedicated to Pierre Fauvel, famous French polychaetologist, and the type species, F. challengeriae McIntosh, 1922, was described based on specimens collected during the HMS Challenger expedition. The phylogenetic affinities of fauveliopsids are unsettled in part due to the fact that only a few species have been included in past analyses; after the analysis of morphological and molecular characters (Zrzavý et al. 2009, figure 6), Fauveliopsidae groups with Cossuridae and Paraonidae, as a sister group to what has been regarded as Cirratuliformia (Cirratulidae, Acrocirridae, Flabelligeridae).            This family includes benthic species that are rarely abundant, and they tend to prefer silty bottoms. Most species have been described from deep-sea locations including trenchs (Menzies George 1967); however, a few shallow water species were described from the Canary Islands (5 m), New Zealand (20 m), and the Adriatic Sea (60 m). Members of the family are free living or find shelter in tubes of cemented silt grains (Blake Petersen 2000, Petersen 2000); they can also be found inside scaphopod, or gastropod mollusk shells, or inside tubular foraminiferans (Bathysiphon Sars, 1872). It should be noted, however, that typical Bathysiphon tests include sponge spicules, and that Psammosiphonella Avnimelech, 1952 was proposed for those agglutinated foraminiferans whose tests do not include sponge spicules; this latter genus has been regarded as distinct (Rögl 1995; Kaminski 2004; Kaminski et al. 2009). This is relevant because at least in some cases, as we show below, fauveliopsid tubes have a complex organization, such that other interpretations might be involved. Another interesting issue is that Malecki (1973) regarded these foraminiferan tests (Bathysiphon and Psammosiphonella) as polychaete tubes, because they lack the characteristic basal embryonic chamber, proloculus, which define foraminiferans. This idea was not followed and the above genera are still regarded as foraminiferans (Kaminski 2004).            Fauveliopsid bodies are subcylindrical, wider medially, or club-shaped; in the latter, the anterior region is the narrower one. Parapodia are displaced dorsally with notopodia being clearly dorsolateral, whereas neuropodia are lateral and chaetae are directed anteriorly, usually along anterior region, and it is related to free living species. The combination of a usually posterior wider region and the parapodial disposition, together with the presence of some anal papillae has made it difficult to assess body polarity and for some descriptions the body ends were incorrectly characterized (Laubier 1972:698; Hartman 1976:236, Fig. 12a). There are four morphological traits of typical polychaete body patterns that can explain this difficulty: 1) anterior region is wider than the rest of the body; 2) segments are less clear cut anteriorly; 3) chaetal bundles are displaced to the anterior border of each chaetiger, being displaced to the median region and eventually towards the posterior region in median to posterior chaetigers; and 4) chaetae are directed anteriorly in a few anterior chaetigers, and towards the posterior region in the rest of the body.            Surprisingly, these patterns are reversed among fauveliopsids because many have evolved to live within tubes, bending their bodies obliquely or ventrally, and by directing their chaetal bundles anteriorly (originally noticed by McIntosh 1922:6). These modifications could provide better anchoring for chaetae and parapodia. Inside gastropod shells, there are different conditions for what lies dorsally or ventrally; this might have selected for body modifications. For example, parapodia become dorsally displaced and this would enlarge ventral and lateral surface areas to be in close contact with the shell.            Katzmann Laubier (1974:10, Fig. 3C) showed that in some fauveliopsids the narrower region is exposed through the shell aperture. Blake Petersen (2000) clarified the body end confusion, standardized concepts about morphological features, and redescribed some species. However, earlier descriptions deserve re-evaluation because of a potential confusion of body ends. Riser (1987) provided some histological details and indicated that stomach contents consisted of foraminiferans and silt, whereas Purschke (1997) made SEM illustrations of nuchal organs.            Hartman (1971:1411) proposed Fauveliopsidae to include four genera that she regarded as flabelligerid-like: Bruunilla Hartman, 1971, Fauveliopsis, Flabelligella Hartman, 1965, and Flota Hartman, 1967. In a subsequent publication, Hartman (1974:199, 235) apparently changed her perspective and transferred Fauveliopsis to the Flabelligeridae; however, in a posthumous publication (Hartman 1978:175) she used the family as originally proposed.            The composition of the Fauveliopsidae has been modified over the years, with Orensanz (1974) transferring Flabelligella to Acrocirridae, Pettibone (1979) indicating that Bruunilla belongs in Polynoidae, and Buzhinskaja (1996) proposing an independent family for Flota. For the latter genus group name, Salazar-Vallejo Zhadan (2007) regarded it as a junior synonym of Buskiella McIntosh, 1885. The family was thus restricted to Fauveliopsis but it now also includes Laubieriopsis Petersen, 2000 and Riseriopsis n. gen.            Three major publications have addressed identification problems in Fauveliopsis. Katzmann Laubier (1974) prepared a key to species based upon the number of chaetigers, integument features and type of chaetae throughout body. Amoureux (1982) compiled the known species and pointed out their number of chaetigers. Hartmann-Schröder (1983) had a different approach and relied more on chaetal patterns than on number of chaetigers.            Because body ends were confused in some of the original descriptions, the species deserve reinterpretation. In order to standardize the morphological features, the diagnoses below combine these approaches and additional observations based upon specimens with some remarks about the match between previous descriptions and these standardized diagnoses, as made elsewhere for tropical American species (Salazar-Vallejo 2009).            In this contribution, we have dealt with all material available of fauveliopsid genera and species. We propose a new genus, Riseriopsis n. gen., to include two species of Fauveliopsis provided with long, posteriorly swollen bodies, with long segments along median region, and two known species are newly combined. Further, four species are newly described, and another one, Laubieriopsis hartmanae (Levenstein, 1970), is redescribed and reinstated.

Sternaspidae (Annelida, Sedentaria) from Vietnam with description of three new species and clarification of some morphological features.

Five sternaspid species were found near Vietnam shores: Sternaspis britayevi sp. nov., S. costata von Marenzeller, 1879, S. nana sp. nov., S. papillosa sp. nov., and S. spinosa Sluiter 1882. Sternaspis britayevi is described from the shallow water in Vietnam inhabiting soft bottoms; it resembles S. spinosa described from Java and S. thorsoni Sendall & Salazar-Vallejo, 2013 described from the Persian Gulf, but differs in having a medially projected and markedly ribbed fan of the ventro-caudal shield and nearly parallel, distally widened and rounded branchial plates. Sternaspis nana sp. nov. is described from Nha Trang Bay; it differs from the other known species by the combination of the following characters: small size, evenly distributed micropapillae and regular rows of long cirriform papillae; posterior chaetal fascicles consisting of single thick chaeta; a ventral shield with smooth integument, without ribs and usually without concentric lines. Sternaspis papillosa sp. nov. is also described from Nha Trang Bay; it resembles S. africana Augener, 1918 and S. andamanensis Sendall & Salazar-Vallejo, 2013 by having similar ventro-caudal shields but differs by body papillation and details of the ventro-caudal shield. Based upon observations of different species some morphological features are clarified: 1) notochaetae are present in introvert chaetigers as delicate capillaries; 2) peg-chaetae are really a dense group of more than 100 thin individual chaetae, embedded in a fibrous matrix, and covered by a common sheath; 3) the pharynx is an eversible, lobed, axial non-muscular proboscis with a ciliated surface; 4) the body cavity is divided by three septa in the anterior body region, and there are no other septa; and 5) an eversible anal peduncle is confirmed, as has been shown by early taxonomists.

Orbiniidae (Annelida: Errantia) from Lizard Island, Great Barrier Reef, Australia with notes on orbiniid phylogeny.

The fauna of Orbiniidae (Annelida: Errantia) from the Lizard Island has been studied. Five species were found and each was redescribed and illustrated using light microscopy and SEM. Scoloplos acutissimus Hartmann-Schröder, 1991 and Scoloplos dayi Hartmann-Schröder, 1980 collected for the first time since their original descriptions and confirmed through re-examination of their type materials. Molecular analyses were carried out using nuclear 18S rDNA and mitochondrial 16S rDNA and CO1 gene sequences with evolutionary distances and the Neighbor-Joining Method. The molecular analyses did not support the monophyly of the genera Scoloplos, Leitoscoloplos, Leodamas, and Naineris, and its results are incongruent with morphological data.

A new species of Fauveliopsidae (Annelida) from the North Sea.

A new species of the genus Laubieriopsis Petersen, 2000 is described based on 28 specimens collected in the north-east part of the North Sea. It is characterized by fixed number of chaetigers (22), paired genital papillae, bidentate neurochaeta of chaetigers 1-4, the absence of acicular chaetae on chaetigers 5-21 and, on the last chaetiger, one acicular and three capillary chaetae enlarged and directed backward. The present study brings the number of known species of Laubieriopsis to five and the number of Northeast Atlantic species of this genus to two.