Native or introduced? A re-evaluation of Pyropia species (Bangiales, Rhodophyta) from Brazil based on molecular analyses

The genus Porphyra sensu lato of the Bangiales has been reported from the Brazilian coast since the 19th century. However, a major worldwide taxonomic revision of the Bangiales indicated that the foliose genus present in Brazil was Pyropia and that Porphyra sensu stricto has not been recorded from this region. A revision of the species of Pyropia in Brazil, based on sequence analysis of molecular markers (rbcL and SSU rDNA) and complemented with morphology, revealed the occurrence of five distinct species in Brazil: P. acanthophora, P. spiralis, P. suborbiculata, P. tanegashimensis and P. vietnamensis. Possible events of Pyropia species introduction in Brazil are discussed in the context of phylogenetic analyses. Pyropia acanthophora and P. spiralis, regarded as southwestern Atlantic species, were not closely related in phylogenetic analyses. Pyropia acanthophora grouped with the possibly introduced Indo-Pacific species P. suborbiculata, P. tanegashimensis and P. vietnamensis. Analysis of available COI-5P and UPA sequences indicated that P. acanthophora occurs in the Hawaiian Islands. These results suggest that P. acanthophora, contrary to previous views, may not be endemic to Brazil. Pyropia spiralis, which is supposedly the only native Pyropia species in Brazil, grouped with species from the Mexican Pacific coast, and its origin along the southwestern Atlantic Ocean and Caribbean Sea is discussed.