ABSTRACT
Over 1100 species of echinoderms are now known to occur in Australian waters. A tropical element accounts for at least two thirds of this number. Analysis of 460 non-endemic, tropical species shows at least six different distribution patterns. Some 35% of these species have an Indo-west Pacifid distribution; about 31% are distributed only through the East Indian region; approximately 16% are shared with the East Indian region and Indian Ocean while 11% are shared with the East Indian region and the west Pacific; 4% and 2% are shared with the Indian Ocean and west Pacific respectively. These patterns of distribution can best be explained as the result primarily of vicariance rather than as a direct result of dispersalism.
