What property of water allows aquatic organisms to function with far fewer supportive structures (tissues) than terrestrial organisms have?

The property of water that allows aquatic organisms to function with far fewer supportive structures (tissues) than terrestrial organisms have is the viscosity. Viscosity is the tendency of how the fluids flow. The molecules with the lowest viscosity is the liquid with the least complex molecular structure. The structure affects the viscosity of the fluid because they are less compact and can flow freely.