Explain the concept of a tolerance range along a tidal gradient and how it governs species distribution.

• A. Species have immersion time and salinity tolerances; distribution along the shore reflects the combination of exposure, evaporation, and salinity stress they can endure.
• B. Tolerance ranges are constant and do not affect distribution.
• C. Only temperature tolerance matters.
• D. Tolerance ranges depend only on predators.

Answer: (A)