A new mesophotic species Platoma piiahiluum sp. nov . (Schizymeniaceae) from the Papahānaumokuākea Marine National Monument, Hawaiʻi, USA

Researchers have discovered a new species of red algae, Platoma piiahiluum, endemic to the mesophotic coral ecosystems of Papahānaumokuākea Marine National Monument. This species, distinguished by its transparent, non-branching thalli and unique mitochondrial genome structure—featuring a stem-loop and inversion—was identified through phylogenetic, genomic, and morphological analyses. The study, utilizing plastid (rbcL) and mitochondrial (COI) markers, along with full-genome sequencing, confirms P. piiahiluum as the second known species of Platoma in Hawaiʻi, with the first, P. ardreanum, inhabiting shallow waters. This finding underscores the high endemic diversity in Hawaiian mesophotic zones and highlights the ecological significance of uninhabited islands within Papahānaumokuākea.

Allsopp, K. R., Cabrera, F. P., Kosaki, R. K., Hauk, B. B., Wagner, D., Matadobra, S. J., & Sherwood, A. R. (2025). A new mesophotic species Platoma piiahiluum sp. nov . (Schizymeniaceae) from the Papahānaumokuākea Marine National Monument, Hawaiʻi, USA. Phycologia, 64(2), 108–117. https://doi.org/10.1080/00318884.2025.2484035