Bibliographic Detail
Zuccarello, G.C., Sandercock, B. & West, J.A., 2002
Reference:
Zuccarello, G.C., Sandercock, B. & West, J.A. (2002). Diversity within red algal species: variation in world-wide samples of Spyridia filamentosa (Ceramiaceae) and Murrayella periclados (Rhodomelaceae) using DNA markers and breeding studies. European Journal of Phycology 37: 403-418.
Abstract:
Molecular and breeding studies on two pan-tropical marine red algae reveal vastly different levels of genetic variation and
reproductive isolation. Sequenced DNA regions from the nuclear, mitochondrial and plastid genomes (partial LSU rRNA,
cox2-3 spacer, RuBisCo spacer, respectively) revealed high genetic variation among individuals of Spyridia ®lamentosa. An
rbcL analysis shows that Spyridia is a monophyletic genus distinct from other Ceramiaceae sampled, suggesting that the
Ceramiaceae could be paraphyletic. There is complete congruence between all data sets of S. ®lamentosa, showing a wellsupported
phylogeographic pattern with samples from the Paci®c distinct from Atlantic and Indian Ocean samples. One
western Mediterranean sample is associated with Atlantic specimens, while an eastern Mediterranean sample has closer
affinities to Paci®c samples, possibly indicating a recent cryptic introduction into the eastern Mediterranean. Limited
breeding studies imply that these samples are mostly reproductively isolated, whereas a successful cross demonstrated
maternal inheritance of organellar DNA. These data indicate that S. ®lamentosa exists as several cryptic species. Murrayella
periclados exhibits low levels of genetic variation and no phylogeographic structure, and almost complete reproductive
compatibility between isolates. This suggests that all M. periclados samples share a recent common ancestor that may have
dispersed relatively rapidly, or that rates of base pair substitution between these two species vary greatly. Rapid longdistance
dispersal of M. periclados is not indicated by what is known of the biology of M. periclados, especially in
comparison with S. ®lamentosa, which appears to be a much better candidate for long-distance dispersal. These data
demonstrate that red algal morphospecies are not equivalent units of diversity, with implications for our view of red algal
biodiversity and evolution.
