The theory of homeoviscous adaptation of membranes applied to deep-sea animals.

Deep-sea organisms live at high pressure and low temperature. These two factors increase the order of the bilayer in cell membranes, and, on the basis of the homeoviscous theory of membrane adaptation, predictions are made of the fluidity and composition of deep-sea membranes. Some of the predictions have been tested using membranes from deep-sea fish and some of the results are consistent with the theory. The conclusion is that the theory receives general support from the deep sea and, conversely, adaptation of membranes to high pressure can be profitably investigated in a more detailed manner by testing further predictions based on the homeoviscous concept.