Fresh water is any body of water with a low salt concentration. Organisms in fresh water various challenges which includes; Osmotic concentration such that fresh water is permanently dilute and most cells cannot function at this concentration of ions. Varying temperatures, variation in oxygen levels and reproduction and life cycle due to permanence of habitat and physiological difficulty of regulating osmotic concentration in larvae and juveniles.
Mainly because it was extremely hot at the beginning of Earth's time.
Jewiwjwiwjjwiwbwjwiwbwhiwhwhwiwiwbwuwijwhe
Phosphorus Gradpoint<span />
