sea butterfly or pteropod Clione antarctica

Clione antarctica is found throughout Antarctic and subantarctic waters and can be found northward to about 36 degrees in some areas [5,8]. In McMurdo Sound, C. antarctica is commonly found near the undersurface of the sea ice and is sparse in water deeper than twenty meters [5]. Localized population density down to twenty meters depth may be as high as 300 per cubic meter [7].

Click on the image at left to see a Quicktime mov video clip of Clione antarctica swimming. C. antarctica is a free-swimming shell-less pteropod mollusc up to 4.2 centimeters long [5]. C. antarctica swims with less than two wing strokes per second and orients itself head up [5].


Clione antarctica deposits a free-floating, gelatinous egg mass, with spawning taking place from November through January [5].

In Antarctic waters, C. antarctica eats a planktonic shelled pteropod mollusc Limacina helicina which it extracts from its shell; further north, it feeds on L. retroversa as well [5].

The medusa Diplulmaris antarctica eats C. antarctica [2,3].

A hyperiid amphipod Hyperiella dilatata grabs Clione antarctica from the water and holds it to itself as a chemical defense against predation [1,4,7]. Predatory fish won't eat the amphipod/C. antarctica combination or C. antarctica itself which has a chemical, pteroenone, which deters feeding [1,4,6,7]. The prey species Limacina helicina of C. antarctica doesn't have pteroenone so it appears that C. antarctica synthesizes it as part of its metabolic processes [6,7].

Taxonomic Note: van der Spoel's classic pteropod work arranged C. antarctica under subspecies or formas of C. limacina [9]. Later it was reestablished to C. antarctica [5]

1: Journal of Organic Chemistry 60(3):780-782, 1995: 2: Pelagic Scyphomedusae (Scyphozoa: Coronatae and Semaeostomeae) of the Southern Ocean. Ronald J. Larson. Washington, DC : American Geophysical Union, 1986; 3: Polar Biology 11(1):19-25, 1990; 4: Nature 346(6283):462-464, 1990; 5: American Malacological Bulletin 8(1):67-75, 1990; 6: Antarctic Journal of the United States 29(5):151-153, 1994; 7: Marine Biology 122:271-277, 1995; 8: Journal of Molluscan Studies 64(3):345-354, 1998; 9: Pseudothecosomata, Gymnosomata and Heteropoda (Gastropoda). S van der Spoel. Utrecht : Bohn, Scheltema & Holkema, 1976

Text ©Peter Brueggeman. Photographs ©M Dale Stokes. Video ©Paul Cziko. Photographs & video may not be used in any form without the express written permission of Paul Cziko & M Dale Stokes.