My research is focused on the study of the diversity, systematics, phylogeny, biogeography, and ecology of Heterobranchia gastropods (sea slug and related groups) at a worldwide scale. I use morphological and molecular data to recognize species and reconstruct hypotheses of evolution and relationship at species level (systematics revisions) and between genera and families (higher level phylogenies). Another focal theme of my research interests is the study of biological diversification in the marine realm. Bringing together systematics, phylogeny, ecology, geography, palaeontology and geotectonics, I generate hypotheses to shed light on the patterns and processes of speciation and extinction that lead to present diversity patterns in the oceans. Some of my ongoing projects relate to the study of the diversity of sea slugs and related fauna in the Azores and the biogeographic patterns and colonization processes of these islands; the deep-sea biodiversity of the Azores; and the study of the diversity, biogeography, and speciation of several shallow and deep-sea genera in the world oceans (Haminoea, Scaphander, Smaragdinella), the deep-sea cephalaspid gastropods off Japan and the lower heterobranch and pyramidellidae gastropods of Norway.