Morpho-molecular description of the new sand-dwelling dinoflagellate genus Aliferia gen. nov. (Dinophyceae) from the Sea of Japan, including two new species

ABSTRACT Two new marine sand-dwelling dinoflagellate species from subtidal sand collected in Peter the Great Bay, Sea of Japan, were described by morphological and molecular methods. Both species were slightly flattened dorsoventrally or laterally, roughly oval in shape, with small epitheca and large hypotheca, with ascending cingulum, and sulcus covered by a wide list of the first postcingular plate. The species differed in the thecal ornamentation, the number of epithecal plates, the shape of the left sulcal list and the shape of the fifth postcingular plate. Phylogenetic reconstructions based on LSU rDNA sequences of the two new species and their morphological characters confirmed their monophyly and justified the establishment of a new genus, Aliferia gen. nov., with Al. nikselinii sp. nov. and Al. kharlamenkoi sp. nov. The new genus was characterized by dorsoventrally or laterally flattened cells with small epitheca and large hypotheca, ascending cingulum, shifted or not shifted sulcus covered by a wide list on the left side, and with one or two ventral spines. Thecal tabulation: APC 3′ 2a 6–7′′ 2? or 3c 5s 5′′′ 1′′′′. Distance-based analyses indicated Diplopsalidoideae as the closest phylogroup to Aliferia. Seven phylogroups of the Amphidiniopsis complex, Herdmania, the Protoperidinium complex, and Archaeperidinium (Clade ‘Y’) were grouped with the highest support values, and Aliferia formed an independent branch basal to members of Clade ‘Y’. The genus Aliferia showed morphological similarity to both sand-dwelling (Amphidiniopsis and Herdmania) and planktonic (Diplopsalidoideae) species. The morphology and phylogeny of Aliferia suggested complex taxonomic relationships between the planktonic and benthic genera.