Mallomonas rimosa sp. nov. (Synurales, Chrysophyceae)—a rare tropical species from Vietnam

Abstract

A new species, Mallomonas rimosa sp. nov., is described from Vietnam based on silica-scale morphology observed using scanning and transmission electron microscopy. Mallomonas rimosa belongs to section Torquatae and is most similar to M. eoa, M. prora, M. serrata, M. scrobiculata, M. pumilio var. dispersa, M. caverna, and M. lanalhuensis. The main distinctive features of scales of the newly described species are the shield ornamentation with small, circular, and evenly spaced pits and the single row of papillae on each side of the anterior flange. Mallomonas rimosa was found in water bodies with acidic conditions, low mineralization, and high temperature.