Two decades of monitoring have revealed over 100 species of coral-reef fish expatriating into SE Australian waters to rocky reef habitats (“vagrants”). Recently, we have observed and commenced monitoring new beds of Pocillopoa aliciae, a subtropical hard coral that has rapidly expanded over temperate reef “urchin barrens” in the last few years. We show that an additional 8 species of vagrant fish have now been recorded in Sydney, only on these coral beds, which also support a much greater overall density of vagrant species (and some temperate species) than surrounding rocky reefs. One coral reef fish Thalasssoma lunare occupies the coral beds in extremely high densities, exhibits spawning behaviour and overwinters on the coral habitat. We discuss the expansion of theses coral beds in the Sydney region and implications for reef fish assemblages.