MOLECULAR SYSTEMATICS OFCERAMIUMANDCENTROCERAS(CERAMIACEAE, RHODOPHYTA) FROM BRAZIL1

Publisher Website
Google Scholar
Abstract
Morphological investigations identified 11CeramiumRoth species, of the 18 previously reported from Brazil. Phylogenetic analyses of sequences of the chloroplast‐encodedrbcL gene confirmed the presence of seven of these species. Three other species are reported from Brazil for the first time.Ceramium affineSetchell & Gardner andC. filiculaHarveyexWomersley were previously known only from the Pacific Ocean (Mexico and Australia, respectively). A new species,C. fujianumBarros‐Barreto et Maggs sp. nov., is described here. Its general habit is similar to that ofC. strictum sensuHarvey from Europe but it has one less periaxial cell thanC. strictum; its cortical filament arrangement is closest toC. deslongchampsiiChauvinexDuby, also from Europe, but whorled tetrasporangia partially covered by cortical cells differ strikingly from the naked protruding tetrasporangia ofC. deslongchampsii.Ceramiumspecies in which each periaxial cell cuts off transversely only a single basipetal cell formed a robust clade. The genusCeramiumas represented in Brazil is not monophyletic with respect toCentrocerasKützing andCorallophilaWeber‐van Bosse;Ceramium nitens, which has axial cells completely covered by rounded cortical cells formed by acropetal and basipetal filaments, did not group with anyCeramiumclade but was weakly allied to a species ofCorallophila. All three BrazilianCentrocerassequences were attributed to a single species,C. clavulatum.