Mediaster Stimpson, 1857

Mah, Christopher L., 2025, New Australian deep-sea Goniasteridae (Asteroidea; Valvatacea), Memoirs of Museum Victoria 84, pp. 49-88 : 76

Mediaster Stimpson, 1857 .

Mediaster . Stimpson, 1857: 530; Sladen, 1889: 263; Perrier, 1894: 377; 1896: 45; Verrill, 1899: 178; Fisher, 1911: 196; Verrill, 1914: 295; 1915: 108; Fisher, 1919: 255; Macan, 1938: 369; H.L. Clark, 1946: 83; Bernasconi, 1963: 11; 1964: 253; Halpern, 1970: 202; 1970b: 45; Clark and Downey, 1992: 251; Mah, 2018: 53.

Diagnosis. (Based on Mah, 2018). Body stellate, tabulate abactinal plates displaying internally radiating ossicles from base of each plate. Abactinal tabulae plates with granules or spinelets. Abactinal plates in most, extending to arm tip, but exceptionally with distalmost superomarginals abutting. Abactinal, marginal, actinal surface covered by granules.

Comments. Mediaster is widely occurring and includes 1 fossil and 18 living, totalling 19 species present in the Atlantic (n=2), Pacific (n=10), Indian Oceans (n=5), 1 from South Africa and one species present in both the Indian and Pacific oceans. Most species occur across a broad depth range from intertidal to 1829 m (e.g. Mah, 2016). Mah (2018) described 3 deep-sea species from the Indian Ocean. Rowe and Gates (1995) listed 3 species recorded from Australian waters, M. arcuatus ( Sladen, 1889) , M. australiensis H.L. Clark, 1916 , and M. praestans Livingstone, 1933 .