DISTRIBUTION OF THE XANTHOPHYLL LOROXANTHIN IN DESMIDS (CHAROPHYCEAE,CHLOROPHYTA)

Forty-seven species of desmids, representing all four families, were e xamined for the presence of the xanthophyll loroxanthin by reverse-pha se high-performance liquid chromatography. In the Desmidiaceae 28 of t he 35 species examined possessed loroxanthin, and in the Mesotneniacea e two of the six examined had loroxanthin, present. All six species of the families Peniaceae and Closteriaceae examined possessed loroxanth in. Although the distribution of boroxanthin appears to be disjunct in the desmids and does not have strict taxonomic significance, it does follow a coherent pattern consistent with current ideas on desmid phyl ogeny. This pattern suggests that loroxanthin synthesis probably evolv ed once in the desmid lineage, with one or more subsequent reversals.