Diversity of the bladed Bangiales along the Peruvian coast and the description of new species of Porphyra and Pyropia

ABSTRACT This study provides a taxonomic evaluation of the bladed Bangiales along the Peruvian coast furthering understanding of the diversity and taxonomy of these seaweeds, focusing on the economically important genera Porphyra and Pyropia. Based on new collections (114 specimens across 1,778 km; 7–17°S), we applied morphological–anatomical and molecular analyses, including species delimitation methods (ABGD and GMYC), to identify three new species. Phylogenetic analyses of rbcL and COI markers, combined with morphological data, confirmed the presence of three Pyropia species: P. orbicularis, P. suborbiculata, and the newly described Pyropia humboldtii sp. nov.; and three Porphyra species: P. acletoi sp. nov. P. tavari sp. nov. and Porphyra sp. CHF (an undescribed genetic species). Pyropia humboldtii sp. nov. with eight haplotypes, exhibited a wide latitudinal distribution from Casma, Ancash (9°S) in Peru to Coquimbo (30°S) in Chile. It displayed considerable frond variability, with colours ranging from light purple to greenish and brownish, and fronds predominantly lanceolate or lobed. The two new Porphyra species showed limited genetic variability: Porphyra acletoi sp. nov. was restricted to the central Peruvian coast (9–11°S), while Porphyra tavari sp. nov. had a distribution range from Malabrigo, La Libertad (7°S) to Pucusana, Lima (12°S). This systematic revision refines our understanding of Bangiales diversity and distribution along the Peruvian coast. It challenges previous morphological identifications by reassigning specimens formerly attributed to Porphyra columbina and P. pseudolanceolata to newly described species: Pyropia humboldtii, Porphyra acletoi, and Porphyra tavari.