In aquatic many animals, the osmotic concentration of the body fluids change with that of the ambient air, water osmotic concentration. Such animals are called
Those which cannot maintain a constant internal environment are called conformers. An overwhelming majority (99 per cent) of animals and nearly all plants cannot maintain a constant internal environment. Their body temperature changes with the ambient temperature. In aquatic animals, the osmotic concentration of the body fluids change with that of the ambient air, water osmotic concentration. These animals and plants are simply conformers.