brittle star Ophiurolepis sp., probably Ophiurolepis gelida

Shown here on a lacy bryozoan, this Ophiurolepis sp. is probably Ophiurolepis gelida which is the most common member of the genus in McMurdo Sound [3]. Dorsal photos are inadequate for distinguishing O. gelida from other Ophiurolepis species [3].

Ophiurolepis gelida is found throughout Antarctica and the Antarctic Peninsula, South Shetland Islands, South Sandwich Islands, and Bouvet Island in depths from 40 to 2,725 meters [2,4,5,6,8]. The pentagonal or rounded-pentagonal disc of O. gelida is flattened and up to 2 centimeters in diameter [2]. The arms of O. gelida are long and tapering and reach a length of six centimeters [2,6]. O. gelida is colored orange-brown or yellowish-brown [2].


Ophiurolepis gelida captures prey or feeds by moving surface sediments into small mounds which are partially or completely engulfed; this feeding behavior gathers small organisms as well as eggs and fecal material [1]. O. gelida feeds on diatoms, silicoflagellates, bryozoans, tunicates/ascidians, foraminifera, polychaetes, gastropods, polychaetes, sponges, bivalve molluscs, amphipods, and euphausiid krill [1,9].

Predators of O. gelida include the brittle star Ophiosparte gigas [7].


Some Ophiurolepis species may be parasitized by an epizoic sponge Iophon radiatus [2]. I. radiatus is dark brown, obscures the brittle star's true color, and grows on the disc and arm bases of Ophiurolepis [2]. Presence of I. radiatus is not definitive for identifying O. gelida; some O. gelida lack it and other species of Ophiurolepis have it [2,3,5].


Here is Ophiurolepis gelida next to the seastar Odontaster validus. Maximum age of O. gelida has been estimated at 33 years [9].

1: 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; 2: The Fauna of the Ross Sea, Part 1, Ophiuroidea. HB Fell. New Zealand Department of Scientific and Industrial Research Bulletin 142, New Zealand Oceanographic Institute Memoir 18, 1961; 3: John Dearborn, personal communication, 1999; 4: Fauna der Antarktis. J Sieg & JW Wagele, eds. Berlin : P. Parey, 1990; 5: AFJ Madsen. B.A.N.Z. Antarctic Research Expedition 1929-1931. Reports, Series B (Zoology and Botany) Volume 9, Part 3, Ophiuroidea. Adelaide : BANZAR Expedition Committee, 1967; 6: Equinodermos Antarticos. III. Ofiuroideos. 1. Ofiuroidoes del Extremo Norte de la Peninsula Antartica. I Bernasconi and MM D'Agostino. Revista del Museo Argentino de Ciencias Naturales "Bernardino Rivadavia" e Instituto Nacional de Investigacion de las Ciencias Naturales. Hidrobiologia 4(2):81-133 and plates, 1974; 7: Polar Biology 16(5):309-320, 1996; 8: Tethys 6(3):631-653, 1974; 9: Okologie und Populationsdynamik Antarktischer Ophiuroiden (Echinodermata), Ecology and Population Dynamics of Antarctic Ophiuroids (Echinodermata). C Dahm. Berichte zur Polarforschung, Reports on Polar Research 194, 1996

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