First record of the red alga Incendia (Peyssonneliales) for Micronesia, including the description of eight new species

The first records of the red algal genus Incendia are reported from five Micronesian islands. The distribution range of Incendia crenata is expanded to include the islands of Kosrae and Pohnpei in Micronesia. Additionally, eight new species are described based on morphological and molecular analyses: Incendia chamoruensis sp. nov., I. dixonii sp. nov., I. fragilis sp. nov., I. orotensis sp. nov., I. gordonii sp. nov., I. lobbanii sp. nov., I. micronesica sp. nov., and I. tsudae sp. nov. While each of the newly described species exhibits the diagnostic features of the genus Incendia, they are distinguished from their congeners by a combination of unique anatomical characters and pronounced genetic divergence. The description of eight new species represents an 80% increase in the global species richness of Incendia. These additions bring the total number of species in the Tropical Northwestern Pacific to 14 out of the 18 known globally. This provisionally establishes this marine province as the primary diversity hotspot for the genus and suggests that peyssonnelioid biodiversity remains substantially underestimated, particularly in tropical regions.