New Research Project on Lower Heterobranchia gastropods

The Heterobranchia is one of the evolutionary lineages of the Gastropoda molluscs and include the former opisthobranchs (e.g., the sea slugs sensu lato), the pulmonates (e.g., slugs and land snails), and a paraphyletic group of predominantly small shelled forms with 2–3 mm, collectively called the “lower” Heterobranchia, which historically had an uncertain taxonomic position and are the focal group of this project. The diversity of “lower” Heterobranchia gastropods (including the Pyramidelloidea) is poorly understood in general and also in Norway, where nine families of these molluscs are cited. Their small size and similar shells pose enormous challenges when it comes to delimit species and understand their taxonomy. During this project these gastropods will be for the first time studied in Norway based on an integrative approach combining, DNA barcoding, phylogenetics, shell characters, and anatomy.

This initiative is a follow up of our previous funded Artsdatabanken projects on the diversity of sea slugs and relatives in Norway, but for the first time will cover the difficult “lower” Heterobranchia. Still, the remaining groups of the Heterobranchia gastropods (Anaspidea, Cephalaspidea, Nudibranchia, Pleurobrancomorpha, Sacoglossa), will be sampled and studied. Particular emphasis is putted on the exploration of understudied habitats included in the “Norwegian Red List of Nature Types”, such as seagrass meadows, maerl coralline algae, and landlocked fjords (polls).

Specimens will be obtained by boat dredging, grabs, snorkelling and scuba diving by direct picking or scrapping substrates. All species will be photographed alive and DNA barcoded. In the case of potential cryptic species-complexes, additional genetic approaches (multilocus-phylogenetics, species delimitation methods, and haplotype network analyses) together with anatomical studies using scanning electron microscopy will be performed. The project benefits from a network of “citizen scientists” established during our last project and from cooperation with scientists from two national universities and four international institutions.

Scientific risponsable of the project: Prof. Manuel Malaquias (Manuel.Malaquias@uib.no)