seastar Diplasterias brucei

Diplasterias brucei is found throughout Antarctica and the Antarctic Peninsula, South Shetland Islands, South Orkney Islands, South Sandwich Islands, and South Georgia Island (six-rayed forma) from 0 to 752 meters depth [3,6,7,8,9,10]. The disc of D. brucei is small and convex; its arms taper gradually to blunt tips [7].



Diplasterias brucei has been collected at sizes up to 23.7 centimeters in radius from its center to the tip of an arm [6,7,10].


Here is a juvenile Diplasterias brucei.

D. brucei color can be light blue-green on top with white spines and a whitish border to the disc and arms with the arm tips blood-red; other recorded colors are pale grey to blue-grey, pale orange or pale blue-grey with a red eye spot at each arm tip, light brown, creamy white with red blotches [7,10].


As shown here, Diplasterias brucei specializes on molluscan prey; it is a significant predator of the bivalve mollusc Limatula hodgsoni which can comprise almost all of its diet [2,3]. D. brucei also eats the muricid gastropod Trophon longstaffi, and is a scavenger on dead material [2,3].


Here is Diplasterias brucei on anchor ice.

D. brucei is a prey item for the anemone Urticinopsis antarctica [2].


Here Diplasterias brucei is humped up and brooding its young in a pocket formed by the underside of its body [1]. Ripe females have been observed year round [5].


Closer view of the eggs being brooded by Diplasterias brucei, as seen from its underside, the ventral side of the seastar.

Brood protection occurs quite commonly among Antarctic marine invertebrates [4].


Yolky eggs of Diplasterias brucei.

Brood protection helps larvae avoid the stresses of the environment and predation [4]. Brooding helps larvae avoid the dangers of being eaten if the larvae were planktonic in a strong seasonal planktonic cycle as seen in Antarctic waters [4].

1: Ecological Monographs 44(1):105-128, 1974; 2: Antarctic Ecology, Volume 1. MW Holdgate, ed. NY: Academic Press, 1970. pp244-258; 3: Adaptations within Antarctic Ecosystems : Proceedings of the Third SCAR Symposium on Antarctic Biology. George A. Llano, ed. Washington : Smithsonian Institution ; Houston, Tex. : distributed by Gulf Pub. Co., 1977. pp.293-326; 4: Adaptations within Antarctic Ecosystems : Proceedings of the Third SCAR Symposium on Antarctic Biology. George A. Llano, ed. Washington : Smithsonian Institution ; Houston, Tex. : distributed by Gulf Pub. Co., 1977. pp.135-157; 5: Marine Biology 104: 41-46, 1990; 6: Fauna der Antarktis. J Sieg & JW Wagele, eds. Berlin : P. Parey, 1990; 7: 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; 8: 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; 9: Discovery Reports 20:69-306 and plates, 1940; 10: 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

Text ©Peter Brueggeman. Photographs ©Paul Cziko, M Dale Stokes & Norbert Wu. Photographs may not be used in any form without the express written permission of Paul Cziko, M Dale Stokes & Norbert Wu. Norbert Wu no longer grants permission for uncompensated use of his photos under any circumstances whatsoever; want more info?