A new crustose brown alga, Endoplura geojensis sp. nov. (Ralfsiales, Phaeophyceae) from Korea based on molecular and morphological analyses

Endoplura , a genus of crustose brown algae, has consisted of five species: E. aurea , E. gyeokpoensis , E. jejuensis , E. koreana , and E. limpeticola . The genus is characterized by intercalary plurangial reproductive structures, which are made up of 2–4 separate parallel filaments that end in 2–5 sterile cells, as well as by cells containing numerous chloroplasts. In this study, phylogenetic analyses of the concatenated rbc L and COI-5P dataset revealed six well-supported lineages within Endoplura . The specimens from Korea formed a distinct and strongly supported clade (BPP, 1.0/BS, 100) representing the new species. This clade was designated as Endoplura geojensis sp. nov., resolved as the sister clade of E. gyeokpoensis , with low support. Genetic distances between E. geojensis sp. nov. and its congeners ranged from 2.6 % to 8.4 % for rbc L and 10.9 %–13.7 % for COI-5P. E. geojensis sp. nov. is characterized by small, yellowish to dark brown crustose thalli up to 1.5 cm in size, a tuft of hairs emerging from the mid to apical cells of erect filaments, plurangia composed of 2–5 separate parallel reproductive filaments ending in 2–3 sterile cells, and unangia associated with paraphyses and soral filaments.