ARE THERE PHYSIOLOGICAL AND BIOCHEMICAL ADAPTATIONS OF METABOLISM IN DEEP-SEA ANIMALS

From the earliest observations of deep-sea animals, it was obvious tha t they differed in many ways from shallower-living relatives. Over the years, there has been speculation that deep-sea animals have unusuall y low rates of biological activity; numerous adaptive scenarios explai ning this have been offered. However, these speculations and scenarios have rarely been tested due to the difficulty of data collection and the inevitable confounding of a number of major variables which covary with depth. In recent years, study of the metabolic properties of ani mals of several phyla from widely differing deep-sea habitats, includi ng the hydrothermal vents, has made it possible, using comparative app roaches, to test hypotheses concerning the metabolic adaptations of de ep-sea animals.