Preliminary results on the DNA barcoding identification of the littoral macroalgal flora of Tiskerth islet, Bejaia (Algeria).

Algeria with its large Mediterranean facade, more than 1200 km, is a country deeply influenced by the sea, which implies the existence of thousands of marine species, notably algae, which have a very important biomass. The first studies on algal flora in Algeria date back to the end of the 18th century (e.g. Desfontaines 1798-1799; Montagne 1846), to which in 20th century were added the notable works of J. Feldmann (1931 and following), the inventory of Perret-Boudouresque and Séridi (1989), and, recently, the pubblications of Ould Ahmed et al. (1995), Seridi et al. (2007) and Ould Ahmed et al. (2013). However, these algological works are essentially based on the morphological and anatomical identifications, which have been challenging due to the plasticity of characters. Marine macroalgae can be notoriously difficult to identify owing to their relatively simple morphology and anatomy, convergence, rampant phenotypic plasticity, and alternation of heteromorphic generations (Saunders, 2005). Algal taxonomists have overcome such difficulties using molecular assisted alpha taxonomy (MAAT), a technique that uses differences in gene sequence data to delineate genetic species groups that are subsequently analysed morphologically and assigned to existing species or established as novel taxa (see Manghisi et al. 2019 and references therein). In this regard, our long-term project focuses on the compilation of a DNA barcode-assisted floristic list of macroalgae collected along the Algerian coast. The first collections were carried out on submerged rocks at a depth of 0-3 m in Tiskerth (36.8153 N 4.9778 E), a small islet in the region of Boulimat, Bejaia, Northeastern Algeria, on September 2018. Collected algae were sorted and morphologically identified following Perret-Boudouresque and Séridi (1989). DNA barcoding identification resolved 13 genetic species, highlighting cryptic diversity relative to taxa reported from the Mediterranean versus from other geographical regions with taxonomic and nomenclature updates provided where possible. To ensure an effective monitoring of biodiversity change over time we propose the use of DNA barcode-assisted floristic lists, which are more convenient and accurate than lists devised from traditional approaches, because associated barcode sequences are easily trackable and each specimen is unequivocally linked to a permanent genetic label regardless of any subsequent taxonomic or nomenclature variation. DNA barcoding surveys contribute to new records to DNA libraries of life, increasing our biodiversity knowledge, which is linked to geographical information and is also freely available to the scientific community. Furthermore, in the context of environmental management, the added value of DNA barcode-assisted identifications is that they give objective and verifiable data, an essential strength if we consider that floristic lists are extensively used by ecologists and environmental agencies as the basis for monitoring studies. To the best of our knowledge, this is the first study of the Algerian macroalgal flora using DNA barcoding methods.