Systematic studies of the Antarctic species of the Phyllophoraceae (Gigartinales, Rhodophyta) based on rbcL sequence analysis

The taxonomic placement of four antarctic species of the marine red algal
family Phyllophoraceae (Gigartinales) is assessed within a preliminary
molecular phylogeny of the family based on direct sequence analysis of the
chloroplast gene rbcL. Parsimony analysis of rbcL sequence indicates that
Gymnogongrus antarcticus and Gymnogongrus turquetii cluster in a clade
consisting predominantly of southern hemisphere species currently placed in
Gymnogongrus and Ahnfeltiopsis, whereas Phyllophora ahnfeltioides and
Phyllophora antarctica cluster in a separate clade that is widely divergent
from the northern hemisphere Phyllophora clade. Result from molecular and
morphological data challenge the current taxonommic concept that type of life
history is a phylogenetically valid criterion for recognition of genera in the
Phyllophoraceae.