Red algal diversity in Tunisia revealed using DNA barcoding

Tunisia, located at the hinge between eastern and western Mediterranean, extends over 1670 km of coastline that constitute a transition zone and habitat diversity between the two basins of the Mediterranean. The coasts are characterized by alternating rocky and soft bottom, promoting marine and coastal biodiversity particularly interesting. However, despite some efforts to better study the biodiversity, data are insufficient due to the heterogeneity of the work. Also, species inventory and their identification pose many problems, particularly concerning the phyla reputedly difficult, such as those of algae. The Tunisia Seaweed Project aims to extensively survey the marine algal flora in Tunisia and generate morphological and molecular data for all three major groups of macroalgae present. DNA barcode data were produced for the red algal samples from the cox1 and rbcL genes of the mitochondrion and plastid, respectively. Phylogenetic trees were built from the molecular data produced thus far in order to assess the algal diversity. This approach is a fast-and-friendly tool for the prompt identification of macroalgal taxa even for non-trained taxonomists and resulted in two new report in Tunisia, Grateloupia filicina and the alien species Hypnea cornuta. Furthermore, it highlighted the presence of other Mediterranean taxa whose status should be better investigated (e.g. Halymenia floresii, Palisada sp., Peyssonnelia sp.). Additional molecular studies as well as careful morphological re-examination of preserved samples will be undertaken to clarify the relationships between these and other genera within the red algae in Tunisia and assign proper taxonomic names where necessary.