March is becoming seaweed month, and this year we go underwater at the Houtman Abrolhos Islands to view one of the most spectacular of the seaweeds. Asteromenia exanimans has a sparkling iridescent thallus that hides its identity as a red seaweed. Small plants are somewhat mushroom-shaped, with a central stalk and horizontal blade, but they grow to become star-shaped and often occur in groups.
When the genus Asteromenia was first described it was thought to include only one widespread species, but subsequent studies have recognised six additional species, of which three can be found in Western Australia. The epithet ‘exanimans’ was coined by Canadian phycologist Gary Saunders and refers to him being left ‘breathless’ when he first viewed the species while diving at the Abrolhos.
Photo: A. Gunness