Houtman Abrolhos
The Houtman Abrolhos is unusual in having a luxuriant and diverse living coral reef at such a high latitude. 194 species in 50 genera have been recorded there, all but two of which are tropical. This is a surprisingly high coral diversity, considering the high latitude of the reef, and the relatively low diversity of other biota. For a full list, see list of corals of the Houtman Abrolhos.
Houtman Abrolhos
The primary piece of evidence for the claim of Portuguese priority is the 16th century Dieppe maps, some of which are said to show the west coast of Australia, including an island at the position of the Houtman Abrolhos. This island is unlabelled on most of the Dieppe maps, but on Pierre Desceliers' 1550 map, it is labelled "Arenes". In 1895, George Collingridge suggested that "Arenes" was a corruption of "Abrolhos", but this was mocked by Heeres in 1898, and according to J. S. Battye "this suggestion can scarcely be regarded seriously. It certainly does not in any way add to the merit of the Portuguese claim".