Epipyxis fenheensis sp. nov., a new species of the genus Epipyxis (Chrysophyceae)

The genus Epipyxis, belonging to the family Dinobryaceae, has been documented to have only sporadic occurrences in freshwater habitats. However, the species diversity of this genus remains largely unexplored due to the scarcity of available molecular sequences. This limitation has significantly hindered a comprehensive understanding of both the species diversity and evolutionary relationships of the genus Epipyxis.

In this study, a new species Epipyxis fenheensis sp. nov. was described from Shanxi Province, China, based on detailed morphological observations and phylogenetic analyses. This species was characterized by a tube-like lorica, a spindle protoplast, two heterokont flagella, and oval or elliptic scales. In addition, phylogenetic analysis based on multi-genes (SSU, LSU, and rbc L) indicated that strain SX 231009 was closely related to E. pulchra.

Given its distinct morphological characteristics and independent phylogenetic position, we propose the designation of this strain as a new species, E. fenheensis sp. nov. The results of this study significantly expand the known diversity of the genus Epipyxis and provide valuable insights into the regional biodiversity and evolutionary history of freshwater chrysophytes.