Acetabularia caliculus J.V.Lamour.
Voy.Uranie,Bot. 621, Pl. 90, Figs 6-7 (1824)

Conservation Code: Not threatened
Naturalised Status: Native to Western Australia
Name Status: Current

Distribution

Beard’s Provinces: Eremaean Province, South-West Province.

IBRA Regions: Carnarvon, Swan Coastal Plain, Warren.

IBRA Subregions: Cape Range, Perth, Warren, Wooramel.

IMCRA Regions: Abrolhos Islands, Central West Coast, Leeuwin-Naturaliste, Ningaloo, Pilbara (nearshore), Pilbara (offshore), Shark Bay, St Vincent Gulf.

Local Government Areas (LGAs): Ashburton, Carnarvon, Cockburn, Dandaragan, Exmouth, Greater Geraldton, Irwin, Karratha, Mandurah, Manjimup, Murray, Rockingham, Shark Bay.

Scientific Description
John Huisman and Cheryl Parker, Thursday 8 September 2016

Habit and structure. Thallus pale green to white (where calcified), to 3–4 cm tall, with a central slightly calcified stalk (230–250 μm diam.) bearing whorls of colourless hairs and an apical cap (to 8 mm diam.) of 18–34 gametangial rays. Gametangial rays truncate to slightly bilobed, 1.7–3.0 mm long and 375–475 µm wide, laterally coherent and forming a cup. Gametangial cysts spherical, formed in the rays, 170–180 μm diam.

Distribution. Widely distributed in tropical and subtropical seas and extending into warm-temperate latitudes.

Habitat. Usually occurs in dense clusters attached to rock or old bivalve shells in the shallow subtidal, often associated with sandy substrata.

[After Huisman, Algae of Australia: Mar. Benthic Algae of North-western Australia, 1. Green and Brown Algae 158 (2015)]