Public parks in the city of Rio de Janeiro, southeast Brazil, and the risk of parasitosis transmission by freshwater gastropods.

Urban parks are not only important for the wellbeing of the human population, but are also widely considered to be potentially important sites for the conservation of biodiversity. However, they may offer risk parasitic infections, such as schistosomiasis and fascioliasis, which are both transmitted by freshwater snails. The present study investigated the occurrence of freshwater gastropods in urban parks of the Brazilian city of Rio de Janeiro, and their possible infection by helminths of medical-veterinary importance. Gastropods were collected from six parks (2021 - 2022) and examined for the presence of larval helminths. In all, 12 gastropod species from different families were collected: Ampullariidae, Assimineidae, Burnupidae, Lymnaeidae, Physidae, Planorbidae, Succineidae, and Thiaridae. The parasitological examination revealed cercaria of three types in five snail species, with the Pleurolophocerca cercariae type in Melanoides tuberculata (the most abundant species), Echinostoma cercariae in Physella acuta and Pomacea maculata, and Virgulate cercariae, in Pomacea sp. and Pomacea maculata. None of the Biomphalaria tenagophila and Pseudosuccinea columella (the most frequent species) specimens were parasitized by Schistosoma mansoni or Fasciola hepatica, respectively. Even so, some parks may represent a considerable potential risk for transmission of both Schistosoma mansoni and Fasciola hepatica, given the presence of these gastropod vectors and the frequent contact of visitors with the waterbodies.

Assessing the role of taxonomic impediment in the knowledge on geographic distribution of Physidae (Gastropoda: Hygrophila) in South America, using an intensive-data approach.

There is a marked disparity in the state of knowledge of Holartic x Neotropical species of the freshwater snail family Physidae; the incipiency of data on Neotropical physids reflecting the lower number of dedicated specialists. The gaps in the knowledge on Neotropical physids have led to historical uncertainty about species validity. Revisiting the species is essential to reduce taxonomic impediment and delineating their probable distribution is the first step to attain this purpose. We aimed at critically analyze occurrence records of South American physids, compiled through an intensive search in the literature, biodiversity and molecular databases. We present a provisional characterization of the distribution of this family in South America, considering the probable versus the poorly documented distribution of the species. The critical underrepresentation of South American physids in collections, molecular databases and literature reinforces the role of taxonomic impediment in delaying the advance of the knowledge on species diversity. Malacological collections represented the main source of records, evidencing the relevance of unpublished data associated to specimens to assess distributional information on neglected groups. As most of the species are represented by shells, the reassessment of species identity and distribution must be done, using molecular and anatomical criteria for species delimitation.

Whole Genome Duplication and Gene Evolution in the Hyperdiverse Venomous Gastropods.

The diversity of venomous organisms and the toxins they produce have been increasingly investigated, but taxonomic bias remains important. Neogastropods, a group of marine predators representing almost 22% of the known gastropod diversity, evolved a wide range of feeding strategies, including the production of toxins to subdue their preys. However, whether the diversity of these compounds is at the origin of the hyperdiversification of the group and how genome evolution may correlate with both the compounds and species diversities remain understudied. Among the available gastropods genomes, only eight, with uneven quality assemblies, belong to neogastropods. Here, we generated chromosome-level assemblies of two species belonging to the Tonnoidea and Muricoidea superfamilies (Monoplex corrugatus and Stramonita haemastoma). The two obtained high-quality genomes had 3 and 2.2 Gb, respectively, and 92-89% of the total assembly conformed 35 pseudochromosomes in each species. Through the analysis of syntenic blocks, Hox gene cluster duplication, and synonymous substitutions distribution pattern, we inferred the occurrence of a whole genome duplication event in both genomes. As these species are known to release venom, toxins were annotated in both genomes, but few of them were found in homologous chromosomes. A comparison of the expression of ohnolog genes (using transcriptomes from osphradium and salivary glands in S. haemastoma), where both copies were differentially expressed, showed that most of them had similar expression profiles. The high quality of these genomes makes them valuable reference in their respective taxa, facilitating the identification of genome-level processes at the origin of their evolutionary success.

Taxonomic insights and evolutionary history in East Asian terrestrial slugs of the genus Meghimatium.

East Asia, specifically the Japanese Archipelago, is a biodiversity hotspot of both vertebrates and invertebrates. Mollusks represent a burst of species diversity in this region due to the effects of biotic and abiotic factors on their morphological traits, such as shell shape and size. However, the evolutionary history of terrestrial slugs in East Asia remains unknown. In the present study, we investigated the molecular phylogeny of terrestrial slugs of the genus Meghimatium. This genus includes three described and eight undescribed species, and our study used all except for two. Based on phylogeny and the species delimitation tests, the genus Meghimatium was split into many putative species, suggesting higher species diversity than previously thought based on morphological and anatomical studies and that almost undescribed species may be inappropriate. Therefore, morphological traits, such as body size and colour, conventionally considered for classification may easily vary or be similar across geographic region. Moreover, the divergence time of this genus is almost concordant with the geographical time scale of the formation of the Japanese mainland. Our findings suggest that molecular phylogenetics helps classify Japanese Meghimatium slugs, but comprehensive taxonomic revisions using multi-locus analyses are needed.

Flow cytometric characterization of the hemocytes of sea hares from tidal pools in Jeju Island off the south coast of Korea.

The members in the family Aplysidae known as sea hares play a crucial role as a grazer in small tidal pools or shallow subtidal hard bottoms. Like other marine gastropods, hemocyte types and functions of sea hares are limitedly known. This study identified and characterized the hemocytes of common Aplysia species Aplysia kurodai, A. juliana, and A. oculifera in rocky tidal pools in Jeju Island off the south coast of Korea using flow cytometry and light microscopy. The flow cytometry identified three different hemocytes in the hemolymph of the three sea hare species: granulocytes, hyalinocytes, and blast-like cells. The granulocytes exhibited pseudopodia on the cell surface and granules in the cytoplasm. Morphology of the hyalinocyte was similar to that of the granulocytes, while they lack cytoplasmic granules. The blast-like cells were small and round, with very thin cytoplasm. The hyalinocytes were the most abundant in the hemolymph, accounting for 89.8-92.6% of the total hemocytes. Flow cytometry indicated that the granulocytes and blast-like cells were less than 5.6% and 5.4% of the total hemocyte populations. Flow cytometry also revealed that the granulocytes and hyalinocytes are engaged in cellular defensive activities such as intra-cellular lysosomal content, phagocytosis, and ROS production. The mean lysosomal contents of the granulocytes (0.4 × 105-0.2 × 105 A U.) were 2-3 times higher than that of hyalinocytes (0.2 × 105-0.6 × 105 A U.). In addition, the ROS production of the granulocytes (0.98 × 106-1.95 × 106 A U.) was about twice higher than that of the hyalinocytes (0.62 × 106-1.14 × 106 A U.). Of the three species of sea hares, the granulocytes showed comparatively higher phagocytosis capacity (70.4-92.3%) than that of the hyalinocytes (34.8-46.0%). Flow cytometry and microscopy indicated that the hemocyte types and their functions were identical, regardless of the species.

Onset of Late Cretaceous diversification in Europe's freshwater gastropod fauna links to global climatic and biotic events.

The Mesozoic rise of the European freshwater gastropod fauna is still poorly understood. Compared to the well documented Cenozoic history, little is known about the patterns and processes underlying the early diversification preceding their extinction crisis at the K-Pg boundary. We assess what is probably a first pulse of diversification of the Cenozoic-type fauna in the Late Cretaceous along with the potential abiotic and biotic controls for shifts in species diversification. We find strong support that the increase in the speciation rate in the Santonian (~ 85 Myr ago) is linked to a global sea level rise, which caused extensive flooding of continental areas and the formation of vast brackish-water ecosystems. The following decline of the speciation rate coincides with a rise in diversity and reflects increasing interspecific competition. The peak in the speciation rate postdates the Cenomanian-Turonian Thermal Maximum, which probably limited the potential for diversification among freshwater gastropods due to ecological constraints. The peak coincides moreover with the end phase of the Cretaceous Terrestrial Revolution, which sparked the radiation of angiosperms. The expansion and diversification of flowering plants, being an important food source for freshwater gastropods today, could have formed a necessary basis for gastropod diversification.

Genetic diversity and structure of Oncomelania hupensis hupensis in two eco-epidemiological settings as revealed by the mitochondrial COX1 gene sequences.

BACKGROUND: Oncomelania hupensis hupensis is the only intermediate host of Schistosoma japonicum, the causative agent of schistosomiasis in China and is therefore of significant medical and veterinary health importance. Although tremendous progress has been achieved, there remains an understudied area of approximately 2.06 billion m2 of potential snail habitats. This area could be further increased by annual flooding. Therefore, an understanding of population genetics of snails in these areas may be useful for future monitoring and control activities. METHODS AND RESULTS: We sampled snails from Hexian (HX), Zongyang (ZY) and Shitai (ST) in Anhui (schistosomiasis transmission control), and from Hengtang (HT), Taicang (TC), Dongsan (DS) and Xisan (XS) in Jiangsu (schistosomiasis transmission interrupted), downstream of Anhui. ST, DS and XS are classified as hilly and mountainous areas, and HX, ZY, TC and HT as lake and marshland areas. The mitochondrial cytochrome c oxidase subunit I gene were sequenced. Out of 115 snails analyzed, 29 haplotypes were identified. We observed 56 (8.72%) polymorphic sites consisting of 51 transitions, four transversions and one multiple mutational change. The overall haplotype and nucleotide diversity were 0.899 and 0.01569, respectively. Snail populations in Anhui had higher genetic diversity than in Jiangsu. 73.32% of total variation was distributed among sites and 26.68% within sites. Snails were significantly separated according to eco-epidemiological settings in both network and phylogenetic analyses. CONCLUSION: Our results could provide important guidance towards assessing coevolutionary interactions of snails with S. japonicum, as well as for future molluscan host monitoring and control activities.

Effects of low pH on the coral reef cryptic invertebrate communities near CO2 vents in Papua New Guinea.

Small cryptic invertebrates (the cryptofauna) are extremely abundant, ecologically important, and species rich on coral reefs. Ongoing ocean acidification is likely to have both direct effects on the biology of these organisms, as well as indirect effects through cascading impacts on their habitats and trophic relationships. Naturally acidified habitats have been important model systems for studying these complex interactions because entire communities that are adapted to these environmental conditions can be analyzed. However, few studies have examined the cryptofauna because they are difficult to census quantitatively in topographically complex habitats and are challenging to identify. We addressed these challenges by using Autonomous Reef Monitoring Structures (ARMS) for sampling reef-dwelling invertebrates >2 mm in size and by using DNA barcoding for taxonomic identifications. The study took place in Papua New Guinea at two reef localities, each with three sites at varying distances from carbon dioxide seeps, thereby sampling across a natural gradient in acidification. We observed sharp overall declines in both the abundance (34-56%) and diversity (42-45%) of organisms in ARMS under the lowest pH conditions sampled (7.64-7.75). However, the overall abundance of gastropods increased slightly in lower pH conditions, and crustacean and gastropod families exhibited varying patterns. There was also variability in response between the two localities, despite their close proximity, as one control pH site displayed unusually low diversity and abundances for all invertebrate groups. The data illustrate the complexity of responses of the reef fauna to pH conditions, and the role of additional factors that influence the diversity and abundance of cryptic reef invertebrates.

A molecular phylogeny of Thuridilla Bergh, 1872 sea slugs (Gastropoda, Sacoglossa) reveals a case of flamboyant and cryptic radiation in the marine realm.

The genus Thuridilla Bergh, 1872 comprises mostly tropical sap-sucking sea slugs species with flamboyantly coloured forms. However, the potential for cryptic or pseudocryptic species masked by convergent or polymorphic colour patterns has not been tested using molecular characters. In this study, we sampled 20 of the 23 recognized worldwide species and performed the most comprehensive molecular phylogenetic analysis of the genus to date using a multi-locus approach combining two mitochondrial (cytochrome c oxidase subunit I, 16S rRNA) and two nuclear (Histone H3, 28S rRNA) genes using maximum likelihood, maximum-parsimony and Bayesian criteria. Three molecular species delimitation methods (ABGD, GMYC, bPTP) and the morphology of radular teeth were additionally used to aid in species delimitation. Our analyses supported 35 species within Thuridilla, of which more than one-third (13) are part of a single radiation here named the Thuridilla gracilis (Risbec, 1928) species-complex. This complex includes T. gracilis, T. splendens (Baba, 1949), T. bayeri (Er. Marcus, 1965), and T. ratna (Er. Marcus, 1965), plus nine additional undescribed species. All 13 species are distinguishable by radular characters, external morphology and their DNA. The detection of this radiation led diversity of Thuridilla to be underestimated by about 25% and provides a new comparative system for studying the role of colour patterns in marine diversification.

Molecular Identification of the Human Pathogen Amphimerus sp. in the Freshwater Snail Aroapyrgus sp. in Ecuador.

Here, we report for the first time the snail intermediate host for the Amphimerus liver fluke, a foodborne trematodiasis. In Ecuador, Amphimerus of the Opisthorchiidae family, infects humans, cats, and dogs, in the tropical Pacific-coast region. Opisthorchiidae comprising also Clonorchis sinensis, Opisthorchis sp., and Metorchis sp., have complex life cycles involving a definitive and two intermediate hosts. We identified morphologically and investigated the presence and prevalence of Amphimerus cercaria and DNA in freshwater snails collected in a human-amphimeriasis endemic region in Ecuador, extracted DNA from snail tissue and emerged cercariae, performed real-time polymerase chain reaction (PCR) with the newly developed primers and probe amplifying the Amphimerus ribosomal internal transcribed spacer 2 (ITS2) region, and sequenced the amplified DNA fragment. We collected 2,800 snails, characterized four species Aroapyrgus sp., Melanoides tuberculata, Biomphalaria cousini, and Aplexa marmorata, isolated three cercariae morphotypes. Of the 640 snails analyzed by qPCR, only Aroapyrgus and one of the three cercariae resulted positive, at a 15% infection prevalence. Polymerase chain reaction revealed that the Aroapyrgus snail and cercaria-morphotype-3 corresponded to Amphimerus, but not to C. sinensis, Fasciola hepatica, or Paragonimus mexicanus. The sequence of amplified DNA product matched that of human-isolated Amphimerus. This finding constitutes the first documentation that Aroapyrgus sp. is the first intermediate host for the Amphimerus sp. that infect humans in Ecuador. The ITS2-gene PCR and sequencing analysis demonstrated a high prevalence of snail infection and proved useful for detecting the infection in snails, which findings can help the establishment of suitable control programs against transmission in any endemic region of interest.

Origin and significance of two pairs of head tentacles in the radiation of euthyneuran sea slugs and land snails.

The gastropod infraclass Euthyneura comprises at least 30,000 species of snails and slugs, including nudibranch sea slugs, sea hares and garden snails, that flourish in various environments on earth. A unique morphological feature of Euthyneura is the presence of two pairs of sensory head tentacles with different shapes and functions: the anterior labial tentacles and the posterior rhinophores or eyestalks. Here we combine molecular phylogenetic and microanatomical evidence that suggests the two pairs of head tentacles have originated by splitting of the original single tentacle pair (with two parallel nerve cords in each tentacle) as seen in many other gastropods. Minute deep-sea snails of Tjaernoeia and Parvaplustrum, which in our phylogeny belonged to the euthyneurans' sister group (new infraclass Mesoneura), have tentacles that are split along much of their lengths but associated nerves and epidermal sense organs are not as specialized as in Euthyneura. We suggest that further elaboration of cephalic sense organs in Euthyneura closely coincided with their ecological radiation and drastic modification of body plans. The monotypic family Parvaplustridae nov., superfamily Tjaernoeioidea nov. (Tjaernoeiidae + Parvaplustridae), and new major clade Tetratentaculata nov. (Mesoneura nov. + Euthyneura) are also proposed based on their phylogenetic relationships and shared morphological traits.

The effect of biologically active compounds in the mucus of slugs Limax maximus and Arion rufus on human skin cells.

Molluscs are one of the sources of biologically active substances, which are now intensively studied, especially for their anti-cancer properties. Malignant melanoma originates from melanocytes, develops very quickly and is associated with poor prognosis. Therefore, the aim of the study was to assess the properties of biologically active compounds in sterile mucus isolated from slugs Limax maximus and Arion rufus. Tested mucus were isolated using the new self-developed method which is safe for the environment and the animal donors. The impact of the mucus on human keratinocytes CCD 1106 KERTr and malignant melanoma cells A-375 was examined using MTT assay and SRB assay, which allowed us to determine the cell metabolic activity and cell number after treating them with slug mucus isolated from Limax maximus and Arion rufus decreased human keratinocytes and melanoma cells metabolic activity as well as manifested properties of reducing the number of cells in both tested cell lines, and therefore can be a source of biologically active substances with anticancer potential.

The multilevel organismal diversity approach deciphers difficult to distinguish nudibranch species complex.

Species identification is a key procedure for broad-scoped ecological, phylogeographic and evolutionary studies. However, to perform a taxonomic study in the molecular era is a complicated task that has many pitfalls. In the present study we use particular examples of common but difficult to distinguish European species within the genus of Polycera (Nudibranchia, Mollusca) to discuss the general issues of the "cryptic species" problem that has broad biological and interdisciplinary importance and can significantly impede ecological, evolutionary, and other biodiversity-related research. The largest dataset of molecular and morphological information for European nudibranchs ever applied encompasses a wide geographical area and shapes a robust framework in this study. Four species are recognized in the species complex, including a new one. It is shown that a lack of appropriate taxonomic analysis led recently to considerable errors in species identity assessment of this complex. Chromatic polymorphism for each species is mapped in a periodic-like framework and combined with statistical analysis of the diagnostic features that considerably facilitates identification of particular species in the complex for biologists and practitioners. The present study evidently shows that "cryptic" and "non-cryptic" components are present within the same species. Therefore, this species complex is well suited for the exploring and testing of general biological problems. One of the main conclusions of this study is that division of biological diversity into "cryptic" and "non-cryptic" components is counterproductive. We propose that the central biological phenomenon of a species can instead be universally designated as multilevel organismal diversity thereby provide a practical set of methods for its investigation.

Evolution and biomineralization of pteropod shells.

Shelled pteropods, known as sea butterflies, are a group of small gastropods that spend their entire lives swimming and drifting in the open ocean. They build thin shells of aragonite, a metastable polymorph of calcium carbonate. Pteropod shells have been shown to experience dissolution and reduced thickness with a decrease in pH and therefore represent valuable bioindicators to monitor the impacts of ocean acidification. Over the past decades, several studies have highlighted the striking diversity of shell microstructures in pteropods, with exceptional mechanical properties, but their evolution and future in acidified waters remains uncertain. Here, we revisit the body-of-work on pteropod biomineralization, focusing on shell microstructures and their evolution. The evolutionary history of pteropods was recently resolved, and thus it is timely to examine their shell microstructures in such context. We analyse new images of shells from fossils and recent species providing a comprehensive overview of their structural diversity. Pteropod shells are made of the crossed lamellar and prismatic microstructures common in molluscs, but also of curved nanofibers which are proposed to form a helical three-dimensional structure. Our analyses suggest that the curved fibres emerged before the split between coiled and uncoiled pteropods and that they form incomplete to multiple helical turns. The curved fibres are seen as an important trait in the adaptation to a planktonic lifestyle, giving maximum strength and flexibility to the pteropod thin and lightweight shells. Finally, we also elucidate on the candidate biomineralization genes underpinning the shell diversity in these important indicators of ocean health.

Phylogeography and molecular species delimitation reveal cryptic diversity in Potamolithus (Caenogastropoda: Tateidae) of the southwest basin of the Andes.

The species of the genus Potamolithus inhabiting the southwestern basin of the Andes are difficult to distinguish due to small size and similar shell morphology. Only Potamolithus australis and Potamolithus santiagensis have been traditionally recognized in this region, but the occurrence of several morphologically similar undescribed populations could increase the regional richness. Here we delimit described and potentially undescribed cryptic species of the genus using partial sequences of the mitochondrial cytochrome c oxidase subunit I (COI) gene. Network analysis and diversity indices inferred six highly differentiated haplogroups, many of them sympatric and widespread in the study area. Phylogeographic analyses suggest a scenario of recent diversification and the occurrence of multiple refuges during the successive Pleistocene glaciations. Phylogenetic analysis also recovered six major clades that showed no relationship with physiography. Species delimitation analyses consistently recognized three or four candidate species apart from P. australis and P. santiagensis. Divergence times indicate that speciation of Chilean Potamolithus began at the end of the Pliocene, probably driven by climatic rather than geographic events. Considering the high inter- and intra-basin genetic diversity, conservation efforts should be focused on protecting sympatric taxa in the basins with the highest species richness.

The Mitridae (Gastropoda: Neogastropoda) of the Miocene Paratethys Sea.

The gastropod family Mitridae in the Miocene Paratethys Sea is revised. In total, 35 species in eight genera are reported. 75% of the species are so far known only from the Paratethys Sea. Biogeographic relations with the adjacent Proto-Mediterranean Sea are moderate and are mainly documented within Cancilla, but nearly absent in the other genera. A slight South-North trend in diversity is observed within the Paratethyan basins, with an outstandingly high diversity of 22 species in the Romanian Faget Basin, but only nine species in the Polish and Ukrainian parts of the Fore-Carpathian Basin. Fraudiziba nov. gen. and Wormsina nov. gen. are introduced as new genera. Twelve species are described as new: Episcomitra antibellardii nov. sp., Episcomitra leopoldiana nov. sp., Episcomitra pseudoincognita nov. sp., Episcomitra missile nov. sp., Episcomitra neubaueri nov. sp., Domiporta amoena nov. sp., Domiporta pulchra nov. sp., Domiporta turpis nov. sp., Nebularia soliphila nov. sp., Cancilla nanostriatula nov. sp., and Cancilla wagreichi nov. sp. Fraudiziba ottomanica nov. sp. is described as new species from the middle Miocene of the Karaman Basin in Turkey. Lectotypes are designated for M. austriaca Csepreghy-Meznerics, 1950, Mitra brusinai Hoernes Auinger, 1880, M. cochlearella Mayer-Eymar, 1890, M. friedbergi Cossmann, 1912, Mitra hoernesi Mayer, 1864, Mitra perangulata Peyrot, 1928, M. praenigra Mayer-Eymar, 1890, and Mitra transsylvanica Hoernes Auinger, 1880. Fraudiziba paratethyca nov. nom. is proposed as new name for Mitra austriaca Csepreghy-Meznerics 1950 [non Mayer-Eymar, 1898].

An overlooked diversity-the Costellariidae (Gastropoda: Neogastropoda) of the Miocene Paratethys Sea.

The Miocene Costellariidae of the Paratethys Sea are revised. In total, 39 species in seven genera are recorded herein, documenting an unexpected diversity of these marine gastropods. The α-diversities of up to 14 species and basin-scale γ-diversities of up to 28 coeval species reveal the Central Paratethys as a unique diversity hot-spot for Miocene Costellariidae. Palaeobiogeographic relationships with the adjacent Proto-Mediterranean Sea are low at species level, and absent for Eastern Paratethyan and north-eastern Atlantic faunas. Antithala nov. gen. and Fedosovia nov. gen. are described as new genera. Bellardithala nov. nom. is introduced as new name for Micromitra Bellardi (1888) [non Meek, 1873]. Eight species are described as new: Antithala claviformis nov. sp., Antithala filipescui nov. sp., Bellardithala kovaci nov. sp., Bellardithala baluki nov. sp., Bellardithala fedosovi nov. sp., Bellardithala dacica nov. sp., Pusia confunda nov. sp., and Vexillum transalpinum nov. sp. Lectotypes are designated for Mitra badensis Hoernes Auinger, 1880, M. brevior Friedberg, 1911, M. fuchsi Hoernes Auinger, 1880, M. intermittens Hoernes Auinger, 1880, M. januszkiewiczi Friedberg, 1928, M. lapugyensis Hoernes Auinger, 1880, M. laubei Hoernes Auinger, 1880, M. michelottii Hörnes, 1852, M. moravica Hoernes Auinger, 1880, M. neugeboreni Hoernes Auinger, 1880, M. partschi Hörnes, 1852, M. pseudorecticosta Boettger, 1906, M. sturi Hoernes Auinger, 1880, M. szobbiensis Halaváts, 1884.

New species of latest Eocene/earliest Oligocene microgastropods (Heterobranchia: Orbitestellidae and Omalogyridae) from the Gries Ranch Formation, Lewis County, Washington State, USA.

Continued sampling of the latest Eocene to earliest Oligocene Gries Ranch Formation in Lewis County, Washington State, has yielded new heterobranch microgastropod species. Orbitestella kieli sp. nov., is the third fossil species of this genus and family Orbitestellidae from western North America. Two new species of Ammonicera, A. rolani sp. nov. and A. danieli sp. nov., are together only the second fossil record of this genus and the family Omalogyridae from the northeastern Pacific Ocean. New specimens of two previously recorded species, O. palaiopacifica Squires Goedert and A. benhami Squires Goedert, from early Eocene rocks of the Crescent Formation provide new data regarding shell morphology. The fossil record of both Ammonicera and Orbitestella in western North America is restricted to early Eocene to earliest Oligocene age rocks in Washington State.

Resolving phylogenetic and classical nomenclature: A revision of Seraphsidae Jung, 1974 (Gastropoda: Neostromboidae).

This revision demonstrates that an integrated taxonomic approach to classical taxonomic practice can lead to increased internal cladistic resolution within a clade, including the recognition of new taxa at all nomenclatural levels. In particular, this revision has two aims: 1) to complete an α-taxonomic revision of Seraphsidae (Stromboidea); and 2) to resolve the infrafamilial relationships within Seraphsidae using morphological cladistics. An annotated synonymy was generated for each taxon, the precedence of names determined, and revised descriptions formulated. Character sets that reflect the synapomorphies within the major subclades of Seraphsidae were coded and a cladogram generated using maximum likelihood within the tnt program with default settings. Four forms of material and evidence were used in this systematic review: 1) the type material for each taxon; 2) non-type physical material; 3) published images; and 4) literary references for specimen localities without illustration. The current morphologically-based classification of Seraphsidae was found to be sound in terms of current species delimitations. Regardless of this, the use of an integrated taxonomy improved understanding of the internal cladistic relationships within Seraphsidae, which led to higher resolution of the internal cladistic arrangements and taxonomic delimitation. Furthermore, this increased resolution is now reflected in the family nomenclature. Two new subfamilies are proposed, Seraphsinae and Pseudoterebellinae, which are used to distinguish the two clades within Seraphsidae based on form: members of Seraphsinae are involute, while members of Pseudoterebellinae are evolute. Pseudoterebellum is proposed as a new genus to show the discontinuity in the fossil record and highlight the structural differences between it and Terebellum. A new species from Jamaica, Seraphs kaindraperi, is described, being the first record from that location and that geological period and is morphologically distinct from other described taxa. This revision included Mauryna within Seraphsidae on the grounds that it provides a basal link to the Seraphsidae sister taxa Semiterebellum and Terebellopsis, all of which are currently contained within Rostellariidae, and all three clades may in time be brought together under one family. All clades have been constructed to be in compliance with both the ICZN and PhyloCode. It was not possible within the context of this revision to test the results of the α-taxonomic findings against phylogenies generated with molecular data. This was due to the high number of extinct taxa within the Seraphsidae.

A new species of Metaruncina (Gastropoda: Heterobranchia: Runcinida) from Vietnam with a discussion on the so-called rudimentary radula in runcinids.

Marine heterobranch slugs of the order Runcinida comprise 61 species, most of which inhabit the Atlantic Ocean and are referred to the genus Runcina. The Runcinida of the Pacific Ocean have been much less studied to date: only 12 species, from the genera Metaruncina Baba, 1967, Rfemsia Chernyshev, 1999, Runcinida Burn, 1963, Runcinella Odhner, 1924, Pseudoilbia M. C. Miller Rudman, 1968, and Runcina Forbes [in Forbes and Hanley], 1851, have been described from the region. Metaruncina, Rfemsia, and Runcinida are found in the Pacific Ocean only (Baba 1954, 1967; Burn 1963; Gosliner 1991; Chernyshev 1998, 1999, 2005, 2006). The genus Metaruncina, endemic from the Pacific coast of Asia, includes two species: M. setoensis (Baba, 1954) and M. nhatrangensis Chernyshev, 2005. The latter is the only runcinid described from the coastal waters of the South China Sea, where it was found in the bays of Nha Trang and Van Phong (Chernyshev 2005). During subsequent expeditions to the coastal waters of Vietnam, this species was also recorded from off Tho Chu Island (09°19'N, 103°30'E) and off Nam Du Island (09°43' N, 104°23' E). However, in addition to this common species, an undescribed species of Metaruncina was collected. A description of this new species is provided in the present paper. Type material was deposited at the Museum of the A.V. Zhirmunsky National Scientific Center of Marine Biology FEB RAS, Vladivostok, Russia (MIMB).