ULVARIA (ULVALES, CHLOROPHYTA) IN EASTERN AUSTRALIA - MORPHOLOGY, ANATOMY AND ONTOGENY COMPARED WITH MOLECULAR-DATA

On the basis of morphology, anatomy, reproduction, and ontogeny of bot h field collected and laboratory cultivated material, all sheet-like a nd fully monostromatic green algae from warm temperate waters of easte rn Australia are referred to the genus Ulvaria Ruprecht. Specimens fro m this region are historically referred to Ulvaria oxysperma (Kuetzing ) Bliding, but few morphological and anatomical features are reliable in establishing species identity. Specimens throughout the region are perennial and exhibit great plasticity with continuous and often large ranges of microscopic and macroscopic features apparent within and be tween collection sites, and even within individual thalli. Detailed st udy of the ultrastructure of the pyrenoid does not provide taxonomical ly unequivocal information. Analyses of ITS sequence data indicate two groups in the isolates examined. Comparison with published ITS sequen ce supports the placement of both groups in Ulvaria, and not Monostrom a Thuret, though only one of these groups may correspond to Ulvaria ox ysperma. Restriction endonuclease analyses of the internal transcribed spacer regions of the ribosomal DNA support this conclusion, and such analyses may offer a fast and inexpensive alternative to sequencing i n some cases. Further investigation is required to ascertain the natur e of the taxonomic relationships between the two groups of isolates.