A DNA barcode inventory of the genus Ulva (Chlorophyta) along two Italian regions: updates and considerations

Abstract

The genus Ulva Linnaeus 1753 is well known for its global distribution and containing many taxonomically debated species. Their morphological plasticity and cryptic nature overrepresent and underrepresent, respectively, the biodiversity of these species. The difficulty in morphologically identifying Ulva species has led to the accumulation of many species names that are currently considered synonyms. The correct identification of these species is crucial due to their significant role in marine ecosystems and mariculture. In the last 30 years, several checklists and taxonomic contributions have been made from the Italian coast on Ulva species, almost entirely based on morphological studies and only a few papers with molecular data have been published. In this study, samples deposited at the Institute of Marine Sciences (ISMAR) and Phycological Lab (PHL) herbaria have been reviewed by sequencing the chloroplast-encoded elongation factor Tu (tufA) barcode marker. The results obtained provide an update of the DNA barcode inventory of Ulva species for the Lagoon of Venice and the Strait of Messina, two ecosystems characterized by a high algal biogeographical diversity and continuous introduction due to anthropogenic activities. Here, ten Ulva species were identified based on molecular data. Furthermore, we record the presence of Ulva chaugulei on the coast of Tunisia.