Pagothenia borchgrevinki lives in the upper six meters of water swimming beneath the sea ice undersurface and entering it to feed and take refuge.
Ice formation decreases with increasing depth due to the effect of pressure on the freezing point.
Shallow water fish have evolved to live in close association with ice. Freezing Avoidance and the Presence of Ice in Shallow Water Antarctic Fishes. B Battaglia, J Valencia and DWH Walton, eds. Cambridge University Press, 1997. Photographs may not be used in any form without the express written permission of Norbert Wu.