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Buccinidae—like other canivorous and predatory molluscs—are generally considered to be occasional visitors or rare colonizers in deep-sea biogenic habitats. However, casual observations during tropical deep-sea cruises suggest that associations between buccinids and sunken wood, in particular, are not fortuitous. Enigmatocolus monnieri has been found to co-occur in Madagascar with bathymodiolines, vesicomyids and solemyids, indicating the presence of seeps, and species of Thermosipho gen. nov. have been sampled by submersibles and remotely operated vehicles, exclusively from hydrothermal vents. A molecular phylogeny (based on CO1, 12S and 28S genes) reveals that buccinid genera potentially associated with sunken wood (Eosipho, Gaillea gen. nov., Calagrassor gen. nov., and Manaria) are closely related to taxa from vents (Thermosipho gen. nov.) and seeps (Enigmaticolus). The anatomy of several dissected species did not reveal any special trait that could be interpreted as a special adaptation to biogenic substrates. Buccinids from sunken wood are most diverse in the Indo-Pacific centre of marine biodiversity, the ‘Coral Triangle’, at depths between 100 and 1000 m, with numerous species still undescribed.

The Terebridae are a diverse family of tropical and subtropical marine gastropods that use a complex and modular venom apparatus to produce toxins that capture polychaete and enteropneust preys. The complexity of the terebrid venom apparatus suggests that venom apparatus development in the Terebridae could be linked to the diversification of the group and can be analyzed within a molecular phylogenetic scaffold to better understand terebrid evolution. Presented here is a molecular phylogeny of 89 terebrid species belonging to 12 of the 15 currently accepted genera, based on Bayesian inference and Maximum Likelihood analyses of amplicons of 3 mitochondrial (COI, 16S and 12S) and one nuclear (28S) genes. The evolution of the anatomy of the terebrid venom apparatus was assessed by mapping traits of six related characters: proboscis, venom gland, odontophore, accessory proboscis structure, radula, and salivary glands. A novel result concerning terebrid phylogeny was the discovery of a previously unrecognized lineage, which includes species of Euterebra and Duplicaria. The non-monophyly of most terebrid genera analyzed indicates that the current genus-level classification of the group is plagued with homoplasy and requires further taxonomic investigations. Foregut anatomy in the family Terebridae reveals an inordinate diversity of features that covers the range of variability within the entire superfamily Conoidea, and that hypodermic radulae have likely evolved independently on at least three occasions. These findings illustrate that terebrid venom apparatus evolution is not perfunctory, and involves independent and numerous changes of central features in the foregut anatomy. The multiple emergence of hypodermic marginal radular teeth in terebrids are presumably associated with variable functionalities, suggesting that terebrids have adapted to dietary changes that may have resulted from predator–prey relationships. The anatomical and phylogenetic results presented serve as a starting point to advance investigations about the role of predator–prey interactions in the diversification of the Terebridae and the impact on their peptide toxins, which are promising bioactive compounds for biomedical research and therapeutic drug development.

During a broad molecular taxonomic and phylogenetic survey of the gastropod superfamily Conoidea, 80 specimens of several species of the genus Gemmuloborsonia were sequenced for the cytochrome c oxidase subunit I gene. The genus, originally established for fossil species from the Plio-Pleistocene of the Philippines, now includes living species from bathyal depths of the Indo-Pacific Oceans. The molecular data demonstrated the presence of five separate entities, while only four ‘morphospecies’ could be isolated by visual examination. The two largest groups, representing separate species from the molecular data, were impossible to distinguish with certainty using shell or anatomical characters. To examine shell morphology in more detail the shape of the last whorl was analysed by Fourier analysis, and the Fourier coordinates were used in canonical variate analysis. The majority of the specimens were separated into two groups, but 21.6% of the specimens were impossible to distinguish by morphological characters. One of these two forms was attributed to the known species Gemmuloborsonia moosai Sysoev & Bouchet, 1996, while the other is described as a new species Gemmuloborsonia clandestina. Bathytoma colorata Sysoev & Bouchet, 2001 is transferred to Gemmuloborsonia on the basis of molecular analysis and radular morphology. Another species, represented in our material by a single specimen, remains undescribed.