Lineaperpetua gen. nov.: a new diatom genus in the Thalassiosirales supported by morphology and molecular data

Based on a combination of morphology and molecular data of ribosomal DNA genes, a new diatom genus Lineaperpetua gen. nov. Yu, You, Kociolek & Wang is described. The features that help define Lineaperpetua at the level of genus include: a tangentially undulated valve face; continuous cribra areolae on the valve interior consisting of pores arranged as strips; single rimoportula located inside the ring of marginal fultoportulae. Additionally, phylogenetic analysis based on nuclear small subunit (SSU) rDNA sequences and nuclear large subunit (LSU) rDNA gene placed the three strains of L. lacustris in a single, monophyletic clade at a considerable sequence distance from the other genera ( Thalassiosira , Conticribra , Planktoniella , Shinodiscus , and other genera) belonging to Thalassiosirales. Despite the similarities with some species of Thalassiosira , Conticribra , and Spicaticribra , the suite of features found in Lineaperpetua differentiate it from these other genera. These molecular data and morphological characters suggest an affinity of the new genus to the Thalassiosiraceae.