Endoplura jejuensis sp. nov. and Endoplura koreana sp. nov. (Ralfsiales, Phaeophyceae) from Korea based on molecular and morphological analyses

The crustose brown algal genus Endoplura has been known as a monotypic genus characterized by its intercalary plurangial reproductive structures composed of 2–4 separate parallel filaments terminated by 2–5 sterile cells and by containing several to many chloroplasts per cell. In this study, Endoplura jejuensis sp. nov. and E. koreana sp. nov. from Korea are newly described based on molecular and morphological analyses. Our phylogenetic analyses of the rbcL gene reveal that E. jejuensis sp. nov. and E. koreana sp. nov. are placed in the same clade with “E. aurea” from Japan with a strong bootstrap supporting value. E. jejuensis is characterized by small and light to dark brown crustose thalli of less than 1 cm diameter, tufts of hairs arising from the basal disc, plurangia composed mostly of two separate parallel reproductive filaments terminated by 2–4 sterile cells, and sessile unangia each with a single paraphysis. E. koreana is distinguished by olive or yellowish-brown crustose thalli of up to 3 cm diameter, tufts of hairs arising from the basal disc, and apical parts of erect filaments, plurangia with 2–5 separate reproductive filaments terminated by 2–8 sterile cells, and sessile unangia with 1–2 paraphyses. Our studies also show that “E. aurea” specimens from Japan may be recognized to be a different species from other Endoplura species.