seastar Porania antarctica glabra

Porania antarctica glabra is found throughout Antarctica and the Antarctic Peninsula, South Shetland Islands, South Sandwich Islands, South Georgia Island, Shag Rocks, Kerguelen Island, Heard Island, Bouvet Island, Marion Island, possibly the Indian Ocean, and off Chile and Argentina from 0 to 3,200 meters depth [1,2,3,5,6]. P. antarctica glabra has a high inflated smooth disc, short arms tapering rapidly to blunt tips, and is concave between arms [3]. P. antarctica glabra has been collected at sizes up to 9.7 centimeters in radius from its center to the tip of an arm [2,3]. Color varies and has been recorded as red purple, brick red, reddish orange, dark orange, bluish white, purplish white, bluish-grey, yellowish white, grey, pale orange, and pale red [3,5,6].

Porania antarctica glabra is a ciliary-mucous feeder consuming the small organisms, diatoms, and detritus that shower down on its back by passing them along to its mouth [1,3].

P. antarctica glabra occasionally is an active predator on larger prey and is a scavenger [1].

Adult Porania antarctica glabra do not have well developed dorsal spines or tubercles as does Porania antarctica [1,3,4,7,8]. Porania antarctica glabra does not have marginal spines on the distal parts of its arms [7]. However this distinction is not so distinct in some specimens and juvenile Porania antarctica glabra may have small tubercular spines that disappear with age [4,5]. Porania antarctica glabra may be a synonym of Porania antarctica or a forma; there are at least two other distinct forms or subspecies [4,7].

1: Adaptations within Antarctic Ecosystems : Proceedings of the Third SCAR Symposium on Antarctic Biology. GA Llano, ed. Washington: Smithsonian Institution, 1977. pp.293-326; 2: Fauna der Antarktis. J Sieg & JW Wagele, eds. Berlin: P Parey, 1990; 3: The Fauna of the Ross Sea, Part 3, Asteroidea. HES Clark. New Zealand Department of Scientific and Industrial Research Bulletin 151, New Zealand Oceanographic Institute Memoir 21, 1963; 4: AM Clark. B.A.N.Z. Antarctic Research Expedition 1929-1931. Reports, Series B (Zoology and Botany) Volume 9, Asteroidea. Adelaide : BANZAR Expedition Committee, 1962; 5: Discovery Reports 20:69-306 and plates, 1940; 6: Equinodermos Antarticos. II. Asteroideos. 5. Asteroideos de la Extremidad Norte de la Peninsula Antartica. I Bernasconi. Revista del Museo Argentino de Ciencias Naturales "Bernardino Rivadavia" e Instituto Nacional de Investigacion de las Ciencias Naturales. Zoologia (aka Ciencias Zoologicas) 9(10):211-281 and plates, 1970 ; 7: Asteroidea with a Survey of the Asteroidea of the Chilean Shelf. FJ Madsen. Lunds Universitets Arsskrift. Ny Foljd, Avd. 2. Bd 52. Nr 2. Kungliga Fysiografiska Sallskapet Handlingar. Ny Foljd, Bd 67, Nr 2. Reports of the Lund University Chile Expedition 1948-49. Number 24. Lund: CWK Gleerup, 1956; 8: Memoirs of Museum Victoria 57(2):167-223, 1998

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