What physiological adaptation allows deep-sea fish to survive at high pressures?

Deep-sea fish have evolved specific physiological adaptations to thrive in the extreme conditions of high pressure found in their environment. One critical adaptation is their relatively less rigid bodies and the presence of specialized membranes.

At great depths, the pressure can exceed hundreds of times that at sea level, which would crush many organisms with traditional rigid body structures. Deep-sea fish have adapted by developing flexible, less dense bodies that can withstand these pressures. This flexibility allows their bodies to compress without suffering damage, allowing for the maintenance of physiological functions under duress.

Additionally, specialized membranes within their cells help in coping with the intense pressure by maintaining cellular integrity and functionality. These adaptations are essential for processes like osmoregulation, respiration, and locomotion, which could be severely compromised in a more rigid-bodied organism.

The other options suggest adaptations like thicker scales, more rigid bodies, or increased buoyancy, which are not conducive to the survival in high-pressure environments typical of the deep sea. Increased rigidity could lead to structural failure under pressure, and thicker scales may not provide the necessary flexibility. Increased buoyancy might work in shallower waters but would be detrimental in deep environments where maintaining a neutral buoyancy is critical for energy efficiency. Thus, the combination of a less