Osmoregulation in Fish Essay

Osmosis in the movement of pee molecules by dint of a selectively porous membrane. It occurs from a region of high wet minginess to a region of low water concentration. The control of water balance in animals is known as osmoregulation. Osmoregulation is a homeostatic mechanism. The personate fluids of a common common salt water slant are hypotonic (higher in water concentration) compared with the surrounding sea water the sea water is consequently hypertonic. Because of this they constantly lose water by osmosis through its selectively permeable gill and gut membranes. To replace its loses and maintain its water balance, the fish drinks the sea water.The chloride secretory cells in the gills of the fish actively secrete the excess salt gained from drinking the sea water back out into the sea by an energy requiring process known as active transport, against a concentration gradient. The kidneys of salt water fish just now contain a a couple of(prenominal) small glomer uli, which results in a low filtration rate of blood and only a small volume of urine being formed. In addition, salt water fish convert their nitrogenous waste to a non-toxic form, trimethylamine oxide, which requires borderline amount of water for its removal.Over millions of years of evolution, clear water fish have adapted to carry out osmoregulation. The body fluids of a fresh water fish are hypertonic compared with the surrounding water and consequently they constantly gain water by osmosis. Fresh water fish gain water through the lining of their stomach and their gut the aforesaid(prenominal) as salt water fish. In order to maintain a water balance, fresh water fish have to constantly swallow excess water. Their kidneys possess a number of adaptations which make the constant inhalation of water easy to cope with their kidneys possess many large glomeruli allowing fast filtration of the blood and the tubules reabsorb mineral salts from the glomerular filtrate back into the bloodstream, resulting in a large volume of very dilute urine. Using chloride secretory cells in their gills, fresh water fish area able to actively uptake mineral salts from the water which are lost in the urine.