To re-evaluate the relationships of the major bivalve lineages, we amassed detailed morpho-anatomical, ultrastructural and molecular sequence data for a targeted selection of exemplar bivalves spanning the phylogenetic diversity of the class. We included molecular data for 103 bivalve species (up to five markers) and also analysed a subset of taxa with four additional nuclear protein-encoding genes. Novel as well as historically employed morphological characters were explored, and we systematically disassembled widely used descriptors such as gill and stomach ‘types’. Phylogenetic analyses, conducted using parsimony direct optimisation and probabilistic methods on static alignments (maximum likelihood and Bayesian inference) of the molecular data, both alone and in combination with morphological characters, offer a robust test of bivalve relationships. A calibrated phylogeny also provided insights into the tempo of bivalve evolution. Finally, an analysis of the informativeness of morphological characters showed that sperm ultrastructure characters are among the best morphological features to diagnose bivalve clades, followed by characters of the shell, including its microstructure. Our study found support for monophyly of most broadly recognised higher bivalve taxa, although support was not uniform for Protobranchia. However, monophyly of the bivalves with protobranchiate gills was the best-supported hypothesis with incremental morphological and/or molecular sequence data. Autobranchia, Pteriomorphia, Heteroconchia, Palaeoheterodonta, Archiheterodonta, Euheterodonta, Anomalodesmata and Imparidentia new clade ( = Euheterodonta excluding Anomalodesmata) were recovered across analyses, irrespective of data treatment or analytical framework. Another clade supported by our analyses but not formally recognised in the literature includes Palaeoheterodonta and Archiheterodonta, which emerged under multiple analytical conditions. The origin and diversification of each of these major clades is Cambrian or Ordovician, except for Archiheterodonta, which diverged from Palaeoheterodonta during the Cambrian, but diversified during the Mesozoic. Although the radiation of some lineages was shifted towards the Palaeozoic (Pteriomorphia, Anomalodesmata), or presented a gap between origin and diversification (Archiheterodonta, Unionida), Imparidentia showed steady diversification through the Palaeozoic and Mesozoic. Finally, a classification system with six major monophyletic lineages is proposed to comprise modern Bivalvia: Protobranchia, Pteriomorphia, Palaeoheterodonta, Archiheterodonta, Anomalodesmata and Imparidentia.

MAINBAZA

Galeommatoidea are bivalves with small (usually 1–15 mm), fragile, sometimes vestigial, shells, occurring free-living or in association with other benthic invertebrates from the intertidal to depths in excess of 7,000 m. They are the most diverse but least studied and most underrepresented group of bivalves in biodiversity surveys and museum collections. The majority of commensal species of Galeommatoidea have dull, frequently uncoloured, unsculptured shells, but free-living species have papillate, sometimes coloured, mantles; they can be gregarious, and superficially resemble crawling gastropods. Many species of Galeommatoidea remain to be discovered, and we argue that future descriptions of free-living new species should ideally include photos of living animals, while many of the historically known species described based on their shells will probably be best treated as nomina dubia.

KAVIENG 2014, KOUMAC 2.1, KOUMAC 2.2, KOUMAC 2.3, PANGLAO 2004, PAPUA NIUGINI, SANTO 2006, ???msg.security.private???

The neogastropod family Columbellidae is a highly successful group of small, primarily epibenthic marine snails distributed worldwide and most abundant in the tropics. The great diversity of the group makes them attractive for studying evolutionary shifts in gastropod anatomy, morphology, ecology and diversity. The existing classification of the family has been based to a large degree on the morphology of the shell and radula. Indeed, membership in the family is traditionally confirmed using the unique morphology of the radula. To reconstruct columbellid phylogeny and assess monophyly of the group, we assembled a multilocus dataset including five mitochondrial and nuclear genes, for 70 species in 31 genera. Phylogenetic analyses using Bayesian inference and maximum likelihood are not well enough resolved to support a subfamilial classification, but do support the monophyly of the family and of several well-defined genera and supra-generic groupings. Two of the most diverse nominal genera, Mitrella and Anachis, are supported as highly polyphyletic. Overall, the resulting topologies indicate that the generic and subfamilial classification is in need of extensive revision but that phylogenomic data are needed to resolve columbellid relationships.

ATIMO VATAE, AURORA 2007, INHACA 2011, KARUBENTHOS 2012, MAINBAZA, MIRIKY, PANGLAO 2004, PAPUA NIUGINI, ???msg.security.private???, SALOMON 2, SALOMONBOA 3, SANTO 2006

Background:  Planaxis sulcatus has been touted as a textbook example of poecilogony, with members of this wideranging Indo-Pacific marine gastropod said to produce free-swimming veligers as well as brooded juveniles. A recent paper by Wiggering et al. (BMC Evol Biol 20:76, 2020) assessed a mitochondrial gene phylogeny based on partial COI and 16S rRNA sequences for 31 individuals supplemented by observations from the brood pouch of 64 mostly unsequenced individuals. ABGD and bGYMC supported three reciprocally monophyletic clades, with two distributed in the Indo-Pacific, and one restricted to the northern Indian Ocean and Red Sea. Given an apparent lack of correlation between clade membership and morphological differentiation or mode of development, the reported 3.08% maximum K2P model-corrected genetic divergence in COI among all specimens was concluded to represent population structuring. Hence, the hypothesis that phylogenetic structure is evidence of cryptic species was rejected and P. sulcatus was concluded to represent a case of geographic poecilogony. Results:  Our goal was to reassess the case for poecilogony in Planaxis sulcatus with a larger molecular dataset and expanded geographic coverage. We sequenced an additional 55 individuals and included published and unpublished sequence data from other sources, including from Wiggering et al. Our dataset comprised 108 individuals (88 COI, 81 16S rRNA) and included nine countries unrepresented in the previous study. The expanded molecular dataset yielded a maximum K2P model-corrected genetic divergence among all sequenced specimens of 12.09%. The value of 3.08% erroneously reported by Wiggering et al. is the prior maximal distance value that yields a single-species partition in ABGD, and not the maximum K2P intraspecific divergence that can be calculated for the dataset. The bGMYC analysis recognized between two and six subdivisions, while the best-scoring ASAP partitions recognized two, four, or five subdivisions, not all of which were robustly supported in Bayesian and maximum likelihood phylogenetic analyses of the concatenated and single gene datasets. These hypotheses yielded maximum intra-clade genetic distances in COI of 2.56–6.19%, which are more consistent with hypothesized species-level thresholds for marine caenogastropods. Conclusions:  Based on our analyses of a more comprehensive dataset, we conclude that the evidence marshalled by Wiggering et al. in support of Planaxis sulcatus comprising a single widespread, highly variable species with geographic poecilogony is unconvincing and requires further investigation in an integrative taxonomic framework.

ATIMO VATAE, INHACA 2011, KAVIENG 2014, KOUMAC 2.1, SANTO 2006

Aim: The unique biodiversity in the Red Sea is the result of complex ecological and evolutionary processes driven by Pleistocene climatic change. Here we investigate the species diversity, phylogenetic relationships and phylogeographical patterns of giant clams in the Western Indian Ocean (WIO) and the Red Sea to explore scenarios of marine speciation in this under-studied region.

ATIMO VATAE, INHACA 2011, KAVIENG 2014, PANGLAO 2004, PAPUA NIUGINI

The tropical deep-water Cominellinae commonly assigned to the genera Manaria E. A. Smith, 1906 and Eosipho Thiele, 1929 are revised. While the taxonomic details at the generic level were discussed by Kantor et al. (2013), the species level is discussed here. Twentyone new species are described: Manaria astrolabis n. sp. (French Polynesia), M. borbonica n. sp. (Réunion), M. circumsonaxa n. sp. (Papua New Guinea and the Solomons), M. corindoni n. sp. (Indonesia), M. corporosis n. sp. (the Solomons, Vanuatu, Coral Sea and New Caledonia), M. explicibilis n. sp. (Papua New Guinea and the Solomons), M. excalibur n. sp. (Indonesia and Western Australia), M. fluentisona n. sp. (the Solomons, Fiji, Wallis and Tonga), M. hadorni n. sp. (Papua New Guinea and New Caledonia), M. indomaris n. sp. (India), M. loculosa n. sp. (Fiji), M. lozoueti n. sp. (North Fiji Basin), M. terryni n. sp. (Mozambique Channel), M. tongaensis n. sp. (Tonga), M. tyrotarichoides n. sp. (Mozambique Channel), Calagrassor bacciballus n. sp. (Philippines), C. delicatus n. sp. (New Zealand), C. hespericus n. sp. (Mozambique), C. pidginoides n. sp. (Philippines, Papua New Guinea, the Solomons and Vanuatu), Enigmaticolus marshalli n. sp. (Kermadec Ridge, Monowai Caldera), and E. voluptarius n. sp. (New Caledonia). Considerable range extensions are recorded: Manaria kuroharai Azuma, 1960 is recorded from the Solomons, New Caledonia, Vanuatu and Tonga; M. brevicaudata (Schepman, 1911) is recorded from Taiwan, the Philippines, the Solomons and Fiji; and Calagrassor poppei (Fraussen, 2001) is recorded from Indonesia and the Solomons. Lathyrus jonkeri Koperberg, 1931, a fossil described from Indonesia, is recorded from the Recent fauna of Indonesia, Philippines and Fiji and is redescribed and placed in Manaria. Sipho jonkeri Koperberg, 1931, another fossil described from Indonesia in the same work, is a secondary homonym of Manaria jonkeri (Koperberg, 1931) and is renamed Manaria koperbergae nom. nov.

AURORA 2007, BATHUS 1, BATHUS 2, BATHUS 3, BATHUS 4, BENTHAUS, BERYX 11, BIOCAL, BIOGEOCAL, ???msg.security.private???, BIOPAPUA, BOA0, BOA1, BORDAU 1, BORDAU 2, CHALCAL 1, CONCALIS, CORAIL 2, CORINDON 2, ???msg.security.private???, ???msg.security.private???, ???msg.security.private???, EBISCO, HALIPRO 1, KARUBAR, MAINBAZA, MIRIKY, MUSORSTOM 10, MUSORSTOM 2, MUSORSTOM 3, MUSORSTOM 4, MUSORSTOM 5, MUSORSTOM 6, MUSORSTOM 7, MUSORSTOM 8, PANGLAO 2005, SALOMON 1, SALOMON 2, SALOMONBOA 3, SANTO 2006, SMIB 4, SMIB 5, SMIB 6, SMIB 8, TAIWAN 2000, TAIWAN 2001, TAIWAN 2002, TAIWAN 2004, TARASOC, TERRASSES, VOLSMAR

Extracting DNA from gastropods presents particular difficulties due to the capacity of the living animal to retract into the shell, resulting in poor penetration of the ethanol into the tissues. Because the shell is essential to establish the link between sequences and traditional taxonomic identity, cracking the shell to facilitate fixation is not ideal. Several methods are currently in routine use to overcome this difficulty, including chemical relaxation, drilling the shell and boiling. Most of these methods are time-consuming, may be safety hazards and constitute a bottleneck in the preparation of large numbers of specimens in the field. We have experimented with a method traditionally used to clean shells that involves placing the living gastropods in a microwave (MW) oven; the electromagnetic radiation very quickly heats both the animal and the water trapped inside the shell, resulting in separation of the muscles that anchor the animal to the shell. Done properly, the body can be removed intact from the shell and the shell voucher is preserved undamaged. To test the method, the bodies of live-collected specimens from two gastropod species were separated from their shell by microwaving and by anesthetizing/drilling. After identical extraction and PCR procedures, the gels showed no difference in DNA quantity or quality, and the resulting sequences are identical within species. The method was then implemented on a large scale during expeditions, resulting in higher percentage of DNA extraction success. The MWs are also effective for quickly and easily removing other molluscs from their shells, that is, bivalves and scaphopods. Workflows implementing the MW technique show a three- to fivefold increase in productivity compared with other methods.

ATIMO VATAE, AURORA 2007, KARUBENTHOS 2012, PANGLAO 2004, PANGLAO 2005, PAPUA NIUGINI, SANTO 2006, ???msg.security.private???

AbstractTarget‐capture approaches have facilitated a rapid growth in the field of phylogenomics but few probe sets exist for molluscs, an exceptionally rich phylum with unparalleled ecological and morphological diversity. We designed and tested the first universal probe set using Phyluce to capture ultraconserved elements (UCEs) and exon loci from the Subclass Caenogastropoda ‐ one of six major lineages of gastropods. The probe set consists of 29,441 probes designed to target 1142 UCE loci and 1933 exon loci (3075 total). In silico analyses of our probe set yielded an average of 2110 loci from genomes and 1389 loci from transcriptomes of diverse caenogastropods, from which an average of 1669 and 849 loci were retained respectively after screening to remove those that matched multiple contigs. Phylogenetic analyses of the loci extracted from transcriptomes produced well‐supported trees very similar to those published based on transcriptomic analyses. Phylogenetic relationships estimated from loci extracted from genomes recover similar phylogenetic relationships, and indicate that the loci targeted with this probe set are informative for resolving deep phylogenetic relationships. An in vitro analysis of the probe set with the Epitoniidae, a diverse caenogastropod family of uncertain affinity and with poorly resolved evolutionary relationships, recovered a total of 2850 loci. Although preliminary, the analysis of loci captured by our probe set for a small number of epitoniid taxa produced a well‐resolved tree indicating that this probe set is also able to resolve relationships at shallower hierarchical scales. Together, the in silico and in vitro analyses indicate that target‐capture enrichment with this probe set is a useful tool for reconstructing phylogenetic relationships across taxonomic levels and evolutionary time scales.

ATIMO VATAE, CORSICABENTHOS 2, KANACONO, KANADEEP 2, KARUBENTHOS 2, KAVIENG 2014, KOUMAC 2.1, KOUMAC 2.3, MADEEP, MADIBENTHOS, SPANBIOS, ZhongSha 2015

Reconstructing historical biogeography of the marine realm is complicated by indistinct barriers and, over deeper time scales, a dynamic landscape shaped by plate tectonics. Here we present the most extensive examination of model-based historical biogeography among marine invertebrates to date. We conducted the largest phylogenetic and molecular clock analyses to date for the bivalve family Cardiidae (cockles and giant clams) with three unlinked loci for 110 species representing 37 of the 50 genera. Ancestral ranges were reconstructed using the dispersal–extinction–cladogenesis (DEC) method with a time-stratified paleogeographic model wherein dispersal rates varied with shifting tectonics. Results were compared to previous classifications and the extensive paleontological record. Six of the eight prior subfamily groupings were found to be para- or polyphyletic. Cardiidae originated and subsequently diversified in the tropical Indo-Pacific starting in the Late Triassic. Eastern Atlantic species were mainly derived from the tropical Indo-Mediterranean region via the Tethys Sea. In contrast, the western Atlantic fauna was derived from Indo-Pacific clades. Our phylogenetic results demonstrated greater concordance with geography than did previous phylogenies based on morphology. Time-stratifying the DEC reconstruction improved the fit and was highly consistent with paleo-ocean currents and paleogeography. Lastly, combining molecular phylogenetics with a rich and well-documented fossil record allowed us to test the accuracy and precision of biogeographic range reconstructions.

CONCALIS, ???msg.security.private???, EBISCO, MAINBAZA, MIRIKY, PANGLAO 2004, PANGLAO 2005, SALOMON 2, SANTO 2006, TERRASSES

Abstract Eyes within the marine gastropod superfamily Stromboidea range widely in size, from 0.2 to 2.3 mm—the largest eyes known in any gastropod. Despite this interesting variation, the underlying evolutionary pressures remain unknown. Here, we use the wealth of material available in museum collections to explore the evolution of stromboid eye size and structure. Our results suggest that depth is a key light-limiting factor in stromboid eye evolution; here, increasing water depth is correlated with increasing aperture width relative to lens diameter, and therefore an increasing investment in sensitivity in dim light environments. In the major clade containing all large-eyed stromboid families, species observed active during the day and the night had wider eye apertures relative to lens sizes than species observed active during the day only, thereby prioritizing sensitivity over resolution. Species with no consistent diel activity pattern also had smaller body sizes than exclusively day-active species, which may suggest that smaller animals are more vulnerable to shell-crushing predators, and avoid the higher predation pressure experienced by animals active during the day. Within the same major clade, ancestral state reconstruction suggests that absolute eye size increased above 1 mm twice. The unresolved position of Varicospira, however, weakens this hypothesis and further work with additional markers is needed to confirm this result.

ATIMO VATAE, CONCALIS, EXBODI, INHACA 2011, KAVIENG 2014, KOUMAC 2.3, MADIBENTHOS, MIRIKY, PAPUA NIUGINI

Members of the gastropod superfamily Stromboidea (Littorinimorpha) are characterised by their elaborate shell morphologies, distinctive mode of locomotion, and often large and colourful eyes. This iconic group comprises over 130 species, including many large and charismatic species. The family Strombidae is of particular interest, largely due to its commercial importance and wide distribution in tropical and subtropical waters. Although a few strombid mitochondrial genomes have been sequenced, data for the other four Recent families in Strom­ boidea are lacking. In this study we report seven new stromboid mitogenomes obtained from transcriptomic and genomic data, with taxonomic representation from each Recent stromboid family, including the first mitoge­ nomes for Aporrhaidae, Rostellariidae, Seraphsidae and Struthiolariidae. We also report a new mitogenome for the family Xenophoridae. We use these data, along with published sequences, to investigate the relationships among these and other caenogastropod groups. All analyses undertaken in this study support monophyly of Stromboidea as redefined here to include Xenophoridae, a finding consistent with morphological and behav­ ioural data. Consistent with previous morphological and molecular analyses, including those based on mitoge­ nomes, monophyly of Hypsogastropoda is confirmed but monophyly of Littorinimorpha is again rejected.

KAVIENG 2014, KOUMAC 2.1, MADIBENTHOS, MIRIKY, PAPUA NIUGINI

Abstract The superfamily Stromboidea is a clade of morphologically distinctive gastropods which include the iconic Strombidae, or ‘true conchs’. In this study, we present the most taxonomically extensive phylogeny of the superfamily to date, using fossil calibrations to produce a chronogram and extant geographical distributions to reconstruct ancestral ranges. From these results, we confirm the monophyly of all stromboidean families; however, six genera are not monophyletic using current generic assignments (Strombidae: Lentigo , Canarium , Dolomena , Doxander ; Xenophoridae: Onustus , Xenophora ). Within Strombidae, analyses resolve an Indo‐West Pacific (IWP) clade sister to an East Pacific/Atlantic clade, together sister to a second, larger IWP clade. Our results also indicate two pulses of strombid diversification within the Miocene, and a Tethyan/IWP origin for Strombidae—both supported by the fossil record. However, conflicts between divergence time estimates and the fossil record warrant further exploration. Species delimitation analyses using the COI barcoding gene support several taxonomic changes. We synonymise Euprotomus aurora with Euprotomus bulla , Strombus alatus with Strombus pugilis , Dolomena abbotti with Dolomena labiosa , and Dolomena operosa with Dolomena vittata . We identified cryptic species complexes within Terebellum terebellum , Lambis lambis , “Canarium” wilsonorum , Dolomena turturella and Maculastrombus mutabilis . We reinstate Rimellopsis laurenti as a species (previously synonymised with R. powisii ) and recognise Harpago chiragra rugosus and Lambis truncata sowerbyi valid at the rank of species. Finally, we establish several new combinations to render Lentigo , Dolomena , and Canarium monophyletic: Lentigo thersites , Dolomena robusta , Dolomena epidromis , Dolomena turturella , Dolomena taeniata , Dolomena vanikorensis , D. vittata , “Canarium” wilsonorum , Hawaiistrombus scalariformis , Maculastrombus mutabilis , Maculastrombus microurceus .

ATIMO VATAE, AURORA 2007, CONCALIS, CORSICABENTHOS 3, ???msg.security.private???, EXBODI, GUYANE 2014, ILES DU SALUT, INHACA 2011, KANACONO, KARUBENTHOS 2, KARUBENTHOS 2012, KAVIENG 2014, KOUMAC 2.1, MADEEP, MADIBENTHOS, MIRIKY, PANGLAO 2004, PAPUA NIUGINI, SANTO 2006, Tuhaa Pae 2013

The hyperdiverse group of venomous Conoidea has eluded attempts to construct a robust and stable classification owing to the absence of a robust and stable phylogenetic framework. New molecular data have greatly enhanced our understanding of conoidean evolution, allowing the construction of a new family-level classification. This expanding framework has also allowed the discovery of several independent lineages that merit recognition at familial rank. One of these, based on seven specimens collected over more than 20 years from deep waters off New Caledonia, represents a unique, monotypic lineage closely related to Mitromorphidae, which we here name as the new family Bouchetispiridae. This new lineage bears a unique combination of teleoconch, protoconch and anatomical characters previously unknown within the Conoidea, including a translucent, fusiform shell with sculpture of strong axial ribs crossed by spiral cords, a multispiral protoconch of only 2.5 whorls with punctate sculpture, hypodermic marginal teeth and a multilayered venom bulb with two layers of muscle separated by connective tissue. This lineage may represent the sole survivor of a previously more diverse clade, or is simply one of many unique taxa that have arisen among the isolated sea mounts off New Caledonia.

AURORA 2007, BIOCAL, EBISCO, NORFOLK 2, PANGLAO 2004, PANGLAO 2005, SALOMON 2, SANTO 2006, TERRASSES

ATIMO VATAE, AURORA 2007, MAINBAZA, PANGLAO 2004, PANGLAO 2005, RAPA 2002, SALOMON 2, SANTO 2006

AURORA 2007, BIOPAPUA, BOA1, CONCALIS, SALOMON 1, SALOMON 2, SALOMONBOA 3, SANTO 2006, TAIWAN 2000

Donacidae is a commercially important family of heterodont bivalves and one of the few bivalve lineages that has successfully colonised brackish and fresh waters. However, to date, no phylogenetic hypothesis exists for this widely distributed group. Here we turn to molecular data from the nuclear and mitochondrial genomes and combine these with the extensive fossil record of donacids to propose an evolutionary hypothesis for the family. Our analyses strongly support the monophyly of Donacidae, including Galatea, Iphigenia and ‘Plebidonax’ deltoides, but render Donax paraphyletic. The subgenus Latona is therefore elevated to genus to accommodate a clade of Indo-Pacific species, while retaining Donax for a clade of mostly Atlantic and American Pacific species, and a few Indo-Pacific species. This latter clade is sister group to Galatea + Iphigenia. The diversification of Donacidae seems to be tightly connected to the opening of the North and South Atlantic Oceans in the Cretaceous, and to the closing of the Tethys Ocean during the Oligocene. Taxonomic actions: Latona columbella (Lamarck, 1818) comb. nov., L. deltoides (Lamarck, 1818) comb. nov., L. dysoni (Reeve, 1854) comb. nov., L. madagascariensis (W. Wood, 1828) comb. nov., L. semisulcata semigranosa (Dunker, 1877) comb. nov., L. spinosa (Gmelin, 1791) comb. nov., L. sordida (Hanley, 1845) comb. nov., L. siliqua (Römer, 1870) comb. nov., L.trifasciata (Linnaeus, 1758) comb. nov. and L. victoris (Fischer-Piette, 1942) comb. nov.Key

ATIMO VATAE, INHACA 2011, KAVIENG 2014, PANGLAO 2004, PAPUA NIUGINI, SANTO 2006

BATHUS 1, BATHUS 2, BATHUS 3, BATHUS 4, BERYX 11, BIOCAL, BIOGEOCAL, CALSUB, CHALCAL 1, CHALCAL 2, CONCALIS, EBISCO, HALIPRO 2, LAGON, LIFOU 2000, LITHIST, MD32 (REUNION), MUSORSTOM 4, MUSORSTOM 5, MUSORSTOM 6, NORFOLK 1, NORFOLK 2, PALEO-SURPRISE, SMIB 2, SMIB 3, SMIB 4, SMIB 8, TERRASSES, VAUBAN 1978-1979, VOLSMAR

MAINBAZA

Identifying life stages of species with complex life histories is problematic as species are often only known and/or described from a single stage. DNA barcoding has been touted as an important tool for linking life-history stages of the same species. To test the current efficacy of DNA barcodes for identifying unknown mollusk life stages, 24 marine gastropod egg capsules were collected off the Philippines in deep water and sequenced for partial fragments of the COI, 16S and 12S mitochondrial genes. Two egg capsules of known shallow-water Mediterranean species were used to calibrate the method. These sequences were compared to those available in GenBank and the Barcode of Life Database ( BOLD). Using COI sequences alone, only a single Mediterranean egg capsule was identified to species, and a single Philippine egg capsule was identified tentatively to genus; all other COI sequences recovered matches between 76% and 90% with sequences from BOLD and GenBank. Similarity-based identification using all three markers confirmed the Mediterranean specimens' identifications. A phylogenetic approach was also implemented to confirm similarity-based identifications and provide a higher-taxonomic identification when species-level identifications were not possible. Comparison of available GenBank sequences to the diversity curve of a well-sampled coral reef habitat in New Caledonia highlights the poor taxonomic coverage achieved at present in existing genetic databases, emphasizing the need to develop DNA barcoding projects for megadiverse and often taxonomically challenging groups such as mollusks, to fully realize its potential as an identification and discovery tool.

AURORA 2007

AURORA 2007, BATHUS 1, BATHUS 2, BATHUS 4, BIOCAL, BOA0, BOA1, HALIPRO 1, MUSORSTOM 10, PANGLAO 2005, SALOMON 1, SALOMON 2, SALOMONBOA 3, SMIB 8

Scallops (Pectinidae) are one of the most diverse families of bivalves and have been a model system in evolutionary biology. However, in order to understand phenotypic evolution, the Pectinidae needs to be placed in a deeper phylogenetic framework within the superfamily Pectinoidea. We reconstructed a molecular phylogeny for 60 species from four of the five extant families within the Pectinoidea using a five gene dataset (12S, 16S, 18S, 28S rRNAs and histone H3). Our analyses give consistent support for the non-monophyly of the Propeamussiidae, with a subset of species as the sister group to the Pectinidae, the Propeamussiidae type species as sister to the Spondylidae, and the majority of propeamussiid taxa sister to the Spondylidae + Pr. dalli. This topology represents a previously undescribed relationship of pectinoidean families. Our results suggest a single origin for eyes within the superfamily and likely multiple instances of loss for these characters. However, it is now evident that reconstructing the evolutionary relationships of Pectinoidea will require a more comprehensive taxonomic sampling of the Propeamussiidae sensu lato.

ATIMO VATAE, AURORA 2007, EBISCO, MAINBAZA, MIRIKY, PANGLAO 2004, SALOMON 2, TARASOC

Cerithium koperbergi is a rare gastropod of the family Cerithiidae from the tropical Indo-West Pacific. The species has a small, unusual shell and often inhabits deeper water, fore-reef habitats that are atypical for the genus. Anatomical investigations reveal that it possesses a combination of features heretofore considered diagnostic of two main cerithiid subfamilies: Cerithiinae and Bittiinae. While the shell is bittiine, the animal lacks mesopodial pedal glands and possesses a seminal receptacle (vs. a spermatophore bursa) in the lateral lamina of the oviduct, which are considered to be cerithiine features. Re-evaluation of the anatomy of Bittium reticulatum, the type species of Bittium, indicates the defining anatomical difference in oviduct anatomy between the two subfamilies does not stand up to closer scrutiny. Partial mitochondrial cytochrome c oxidase I (COI) sequences support the interpretation that C. koperbergi is a species complex around the western Pacific rim comprising three divergent mitochondrial lineages. Bayesian analysis of partial mitochondrial COI and 16S rRNA sequences confirm the placement of the C. koperbergi complex within a monophyletic Bittiinae, despite the apparent absence of a unifying anatomical feature. Species in the C. koperbergi complex are here united in Pictorium nov. gen. and two species are described as new. It is hypothesized that features of the midgut may be diagnostic of the Bittiinae, but more comparative data are needed.

ATIMO VATAE, LIFOU 2000, PANGLAO 2004, PANGLAO 2005, SALOMON 1, SANTO 2006

The genus Clea from SE Asia is from one of only two unrelated families among the megadiverse predatory marine Neogastropoda to have successfully conquered continental waters. While little is known about their anatomy, life history and ecology, interest has grown exponentially in recent years owing to their increasing popularity as aquarium pets. However, the systematic affinities of the genus and the validity of the included species have not been robustly explored. Differences in shell, operculum and radula characters support separation of Clea as presently defined into two distinct genera: Clea, for the type species Clea nigricans and its allies, and Anentome for Clea helena and allies. A five-gene mitochondrial (COI, 16S, 12S) and nuclear (H3, 28S) gene dataset confirms the placement of Anentome as a somewhat isolated offshoot of the family Nassariidae and sister to the estuarine Nassodonta. Anatomical data corroborate this grouping and, in conjunction with their phylogenetic placement, support their recognition as a new subfamily, the Anentominae. The assassin snail Anentome helena, a popular import through the aquarium trade so named for their voracious appetite for other snails, is found to comprise a complex of at least four species. None of these likely represents true Anentome helena described from Java, including a specimen purchased through the aquarium trade under this name in the US and one that was recently found introduced in Singapore, both of which were supported as conspecific with a species from Thailand. The introduction of Anentome “helena” through the aquarium trade constitutes a significant threat to native aquatic snail faunas which are often already highly imperiled. Comprehensive systematic revision of this previously unrecognized species complex is urgently needed to facilitate communication and manage this emerging threat.

ATIMO VATAE, BIOPAPUA, EXBODI, INHACA 2011, KARUBENTHOS 2012, MAINBAZA, PANGLAO 2004, ???msg.security.private???, SANTO 2006

A new genus, Limatium gen. n., and two new species, L. pagodula sp. n. and L. aureum sp. n. are described, found on outer slopes of barrier reefs and fringing reefs in the South Pacific. They are rare for cerithiids, which typically occur in large populations. The two new species are represented by 108 specimens sampled over a period of 30 years, only 16 of which were collected alive. Three subadults from the Philippines and Vanuatu likely represent a third species. In addition to their rarity, Limatium species are atypical for cerithiids in their smooth, polished, honey to golden brown shells with distinctive white fascioles extending suture to suture. The radula presents a unique morphology that does not readily suggest an affinity to any of the cerithiid subfamilies. Two live-collected specimens, one of each species and designated as holotypes, were preserved in 95% ethanol and sequenced. Bayesian analysis of partial COI and 16S rDNA sequences demonstrates a placement in the Bittiinae, further extending our morphological concept of the subfamily.

ATIMO VATAE, BATHUS 1, BENTHAUS, BORDAU 2, CORAIL 2, EBISCO, INHACA 2011, LAGON, LIFOU 2000, MONTROUZIER, MUSORSTOM 3, PANGLAO 2004, RAPA 2002, SANTO 2006, Tuhaa Pae 2013, ???msg.security.private???

The Tonnoidea is a moderately diverse group of large, predatory gastropods with ∼360 valid species. Known for their ability to secrete sulfuric acid, they use it to prey on a diversity of invertebrates, primarily echinoderms. Tonnoideans currently are classified in seven accepted families: the comparatively well known, shallow water Bursidae, Cassidae, Personidae, Ranellidae, and Tonnidae, and the lesser-known, deep water Laubierinidae and Pisanianuridae. We assembled a mitochondrial and nuclear gene (COI, 16S, 12S, 28S) dataset for ∼80 species and 38 genera currently recognized as valid. Bayesian analysis of the concatenated dataset recovered a monophyletic Tonnoidea, with Ficus as its sister group. Unexpectedly, Thalassocyon, currently classified in the Ficidae, was nested within the ingroup as the sister group to Distorsionella. Among currently recognized families, Tonnidae, Cassidae, Bursidae and Personidae were supported as monophyletic but the Ranellidae and Ranellinae were not, with Cymatiinae, Ranella and Charonia supported as three unrelated clades. The Laubierinidae and Pisanianuridae together form a monophyletic group. Although not all currently accepted genera have been included in the analysis, the new phylogeny is sufficiently robust and stable to the inclusion/exclusion of nonconserved regions to establish a revised family-level classification with nine families: Bursidae, Cassidae, Charoniidae, Cymatiidae, Laubierinidae, Personidae, Ranellidae, Thalassocyonidae and Tonnidae. The results reveal that many genera as presently circumscribed are para- or polyphyletic and, in some cases support the rescue of several genus-group names from synonymy (Austrosassia, Austrotriton, Laminilabrum, Lampadopsis, Personella, Proxicharonia, Tritonoranella) or conversely, support their synonymization (Biplex with Gyrineum). Several species complexes are also revealed that merit further investigation (e.g., Personidae: Distorsio decipiens, D. reticularis; Bursidae: Bursa tuberosissima; Cassidae: Echinophoria wyvillei, Galeodea bituminata, and Semicassis bisulcata). Consequently, despite their teleplanic larvae, the apparently circumglobal distribution of some tonnoidean species is the result of excessive synonymy. The superfamily is estimated to have diverged during the early Jurassic (∼186 Ma), with most families originating during a narrow ∼20 My window in Albian-Aptian times as part of the Mesozoic Marine Revolution.

ATIMO VATAE, AURORA 2007, CONCALIS, EBISCO, GUYANE 2014, INHACA 2011, KARUBENTHOS 2, KARUBENTHOS 2012, MAINBAZA, MIRIKY, NORFOLK 2, PAKAIHI I TE MOANA, PANGLAO 2004, PANGLAO 2005, SALOMON 2, SANTO 2006, TAIWAN 2004, TERRASSES, ???msg.security.private???, ZhongSha 2015

The cerithioid Supplanaxis nucleus (Bruguière, 1789) is widespread in the Caribbean, where it lives in often dense aggregates on hard surfaces in the middle-high intertidal. Molecular evidence shows that it comprises two species that are in fact morphologically diagnosable. We fix the nomenclature of Supplanaxis nucleus by designating a sequenced neotype from Bruguière’s historical locality of Barbados, and identify the second, cryptic species as S. nancyae (Petuch, 2013). The two live syntopically across the Caribbean and form a closely related species group with the Panamic S. planicostatus (G.B. Sowerby I, 1825). Planaxis nucleola Mörch, 1876, described from St Croix, in the Virgin Islands, never again recorded in the literature but listed as a synonym of S. nucleus in taxonomic authority lists, is recognized as a valid species of Hinea Gray, 1847. Proplanaxis Thiele, 1929 and Supplanaxis Thiele, 1929, are synonyms and the latter is given precedence over the former.

KARUBENTHOS 2012

Carnivory is unusual among bivalve molluscs and is limited to a few families in the distantly related orders Pectinida, Mytilida and Anomalodesmata. Despite the significance of dietary shifts in the evolution of the bivalves, the anatomy of the alimentary system, and of the gastric chamber in particular, has been described in detail for only a few carnivorous species. Here we describe the anatomy of the gastric chamber in a pectinid, Propeamussium jeffreysii, and an anomalodesmatan, Bathyneaera demistriata, expanding the known morphological disparity of the alimentary system in both groups. We found the stomachs of both to be modified to varying degrees for a carnivorous habit, with thickened, muscular walls, extensive cuticular linings, and reduced sorting areas and gastric chamber compartments (i.e. the dorsal hood, the left pouch and the food-sorting caecum). Despite some superficial similarity, each retains distinct hallmarks of their ancestry among filter-feeding relatives, allowing precise homology assessment of individual characters to differentiate between them. In addition, we found that the gastric chamber of P. jeffreysii represents an intermediate morphology between previously described P. lucidum and filter-feeding pectinids. Consequently, variation in the anatomy of the gastric chamber in Pectinida parallels a previously identified trend towards greater specialization for carnivory in the Anomalodesmata. Our results indicate that the current classification scheme of stomach types does not reflect phylogenetic affinity across the Bivalvia and highlight the need for accurate homology assessment of individual characters of the gastric chamber for inferring evolutionary relationships.

MAINBAZA

Elaphriella n. gen. is a new genus of small to fairly large (up to 18 mm) solariellids superficially resembling the genus Archiminolia Iredale, 1929. The latter differs, among others, by a much thicker columella, spiral cords or grooves that often continue on the body whorl and spiral cords inside the umbilicus. The two genera form distinct clades in a molecular phylogeny of the family Solariellidae. Seven new species are described, all from deep water (300-900 meters) in the South and West Pacific: Elaphriella cantharos n. sp., E. eukhonikhe n. sp., E. paulinae n. sp., E. wareni n. sp., E. dikhonikhe n. sp., E. helios n. sp. and E. leia n. sp.

BATHUS 4, BENTHAUS, BIOPAPUA, BOA1, EBISCO, KARUBAR, MUSORSTOM 10, MUSORSTOM 7, PANGLAO 2005, SALOMON 1, SALOMON 2, SALOMONBOA 3, TARASOC, TERRASSES