The marine waters of the Houtman Abrolhos, an island chain off the coast of Western Australia, has been recorded as containing 172 species of echinoderm in ?? genera. This extremely high diversity has been attributed to a combination of factors, namely: the position of the Houtman Abrolhos within a biotone between temperate and tropical waters; the wide variety of habitats; and the Leeuwin Current, which both transports tropical species southwards, and keeps the reef warm enough for them to survive. This is a list of echinoderms of the Houtman Abrolhos:

Crinoidea

Asteroidea

Ophiuroidea

Echinoidea

Holothuroidea