Molecular, Morphological and Chemical Diversity of Two New Species of Antarctic Diatoms, Craspedostauros ineffabilis sp. nov. and Craspedostauros zucchellii sp. nov.

The current study focuses on the biological diversity of two strains Antarctic diatoms (strains IMA082A and IMA088A) collected isolated from Ross Sea (Antarctica) during XXXIV Italian Expedition. Both species presented typical morphological characters genus Craspedostauros: cribrate areolae, “fore-and-aft” chloroplasts a narrow “stauros”. This classification is congruent with molecular phylogeny based concatenated 18S rDNA-rbcL-psbC alignment, which showed that these algae formed monophyletic lineage including six taxonomically accepted Craspedostauros. Since evolution this others raphe-bearing “stauros” particularly challenging their still debated, we tested alternative tree topologies to evaluate relationships among taxa. metabolic fingerprinting approach was implemented for assessment chemical IMA088A. In conclusion, combining (1) traditional features used in identification, (2) phylogenetic analyses small subunit rDNA (18S rDNA), rbcL psbC genes, (3) fingerprint, described IMA088A as Craspedostauros ineffabilis sp. nov. zucchellii new species, respectively.