Diversity, species concepts and phylogenetic relationships of some marine algae in a perspective of Biodiscovery
B. J. Moniz, Monica
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The overall goal was to investigate the genetic diversity, phylogenetic relationships and taxonomy of some groups of marine algae of particular interest from a taxonomic and biogeographic point of view in a perspective of biodiscovery. The order Prasiolales was chosen because its evolutionary history and classification are still in need of clarification. The results add substantial taxonomic and biogeographic coverage to previous studies and other molecular markers (rbcL, psaB and tufA). Two new species were described: Rosenvingiella tasmanica M.B.J.Moniz, Rindi & Guiry from Tasmania and Prasiola glacialis M.B.J.Moniz, Rindi, Novis, Broady & Guiry from Antarctica. Some records reassessed: samples previously classified as R. polyrhiza (Rosenvinge) P.C.from Australia was referred to R. constricta (Setchell & N.L.Gardner) P.C.Silva and samples formerly classified as Prasiola crispa (Lightfoot) Kützing are P. borealis M.Reed. Antarctic cryptic species that were previously confused P. crispa include genuine P. crispa, P. antarctica Kützing resurrected as an independent species and the new species P. glacialis. Marine samples of Prasiola from North Atlantic and the northwestern Pacific were sequenced to help clarifying species circumscriptions in this group. Results support the conspecificity of P. stipitata Suhr ex Jessen and P. meridionalis Setchell & N.L.Gardner. To further understand the origin of bioactives produced by sponges their symbionts, eukaryotes associated with the sponge Haliclona indistincta investigated using morphological observations and next generation sequencing (NGS). Morphological investigation revealed the presence of 66 algal species, mostly filamentous, which colonized the surface of the sponge and did not penetrate deeply into it. In the course of one year, this community varied on temporal scales of season and sampling date. In the NGS study, focus was given to the eukaryotic diversity associated with the sponge often ignored in similar studies. Data shows a high biodiversity of operational taxonomic units (OTUs) often represented by unique sequences. Possible fungal and dinoflagellate symbionts were present but diatoms were underrepresented compared to seawater perhaps due to active protection by the sponge. Divergence in the sponge rRNA 18S gene suggests the presence of multiple copies.