NON-GENICULATE SPECIES OF CORALLINACEAE (CORALLINALES, RHODOPHYTA) IN SHARK BAY, WESTERN-AUSTRALIA - BIODIVERSITY, SALINITY TOLERANCES AND BIOGEOGRAPHIC AFFINITIES

At least 10 species of non-geniculate Corallinaceae (Corallinales, Rhodophyta) occur in Shark Bay, Western Australia. None are new to science, but seven are newly recorded for Shark Bay. Pertinent remarks are provided for each species along with references to detailed morphological/anatomical accounts and data on geographic distribution and substratum range. Within the natural salinity gradient in Shark Bay, four species (Hydrolithon cymodoceae, H. farinosum, Pneophyllum caulerpae, P. fragile) were found at salinity levels > 50 parts per thousand, four (Lithophyllum bermudense, L. pustulatum, Mesophyllum engelhartii, Neogoniolithon brassica-floridum) occurred in metasaline waters (39-50 parts per thousand) and two (Hydrolithon onkodes, Lithophyllum chamberlainianum) occurred only at oceanic salinities (37-38 parts per thousand). All 10 species found in Shark Bay also occur in southern Australia, suggesting that in terms of Corallinaceae lacking genicula, the subtropically situated Shark Bay shows temperate biogeographic affinities. This is in agreement with the reported affinities of Shark Bay seagrasses and their epiphytes but contrasts with the reported tropical affinities of benthic macroalgal species recorded from the bay.