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

At least 10 species of non-geniculate Corallinaceae (Corallinales, Rho dophyta) occur in Shark Bay, Western Australia. None are new to scienc e, but seven are newly recorded for Shark Bay. Pertinent remarks are p rovided for each species along with references to detailed morphologic al/anatomical accounts and data on geographic distribution and substra tum range. Within the natural salinity gradient in Shark Bay, four spe cies (Hydrolithon cymodoceae, H. farinosum, Pneophyllum caulerpae, P. fragile) were found at salinity levels > 50 parts per thousand, four ( Lithophyllum bermudense, L. pustulatum, Mesophyllum engelhartii, Neogo niolithon brassica-floridum) occurred in metasaline waters (39-50 part s per thousand) and two (Hydrolithon onkodes, Lithophyllum chamberlain ianum) occurred only at oceanic salinities (37-38 parts per thousand). All 10 species found in Shark Bay also occur in southern Australia, s uggesting that in terms of Corallinaceae lacking genicula, the subtrop ically situated Shark Bay shows temperate biogeographic affinities. Th is is in agreement with the reported affinities of Shark Bay seagrasse s and their epiphytes but contrasts with the reported tropical affinit ies of benthic macroalgal species recorded from the bay.