AZOOXANTHELLATE SCLERACTINIA (CNIDARIA ANTHOZOA) OF WESTERN AUSTRALIA

WA Museum Records and Supplements | Updated 1 decade ago

Abstract - One hundred five species of azooxanthellate Scleractinia are known from Western Australia. Seventy of these species are reported herein as new records for Western Australia, 57 of which are also new to Australia. Eleven new species are described. The study was based on an examination of approximately 1725 specimens from 333 stations, which resulted in additional records of 98 of the 105 known species. New material was examined from six museums, as well as the historical material of Folkeson (1919) deposited at the Swedish Museum of Natural History.

A majority (69/105 species) of the azooxanthellate species known from Western Australia occur in the tropical region of the Northern Australian Tropical Province (bordered to the south by the Houtrnan Abrolhos Islands and Port Gregory), which can be considered as a southern extension of the larger Indo-West Pacific tropical realm. Nine species are endemic to this region, and the highest latitudinal attrition of species occurs between Cape Jaubert and the Dampier Archipelago. Another 20 species, also known from tropical regions, extend to varying degrees into the Southern Australian Warm Temperate Province. Twelve species are restricted to warm temperate waters of the Southern Australian Warm Temperate Region, most of these species being relatively shallow in depth distribution. A majority of species (53) occur at depths shallower than 200 m, 46 occur exclusively deeper than 200 m (to 1011 m), and 6 species cross the 200 m isobath.

Commensal relationships (galls) with ascothoracidan crustaceans were found with two corals hosts (Madrepora oculata and Deltocyathus magnifieus), and with acrothoracican cirripedes (thecal borings) with six coral hosts: Flabellum politum, Truncatoflabellum folkesoni, T. formosum, T. australiensis, Javania lamprotichum, and Dendrophyllia alcocki.