Do fish ever get thirsty?
Sam Saghir-Pashley from Bedfordshire (Age 5-14)
Filed under: age 5-14, Animals Big Questions, Answered Big Questions, Biology Big Questions, Dinah Barry's Big Answers, Mike McDermott's Big Answers
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Do fish ever get thirsty?
Sam Saghir-Pashley from Bedfordshire (Age 5-14)
Filed under: age 5-14, Animals Big Questions, Answered Big Questions, Biology Big Questions, Dinah Barry's Big Answers, Mike McDermott's Big Answers
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The answer is no. Fish have plenty of water to quench their thirst
Fish in fresh water have to get rid of all the water that diffuses into their bodies so they certainly never feel thirsty. Although their skins are fairly waterproof, their gills are not and water moves into their bodies because fresh water is more watery than the fluids inside the fish.
Most marine fish however lose water through their gills because the sea is salty so it is less watery than theri body fluids. They swallow water to replace what they lose. Because the water is salty they have to remove and excrete the salt so I expect that if the sea were to become saltier, they could get thirsty.
Fish-like sharks are different. Water doesn’t diffuse into their bodies because their bodies are equally watery to the sea. Again I think they might have a problem if the got saltier.
It’s a matter of osmoconformers and osmoregulators, the former adopt the ionic balance of their environment, the later regulate their internal environment so that it is best for them.
The main ions involved are sodium(Na) which is positively charged and Chlorine (Cl) which is negatively charged. Freshwarter fish take in water by osmosiss and lose salts to the environment, so produce copious amounts of dilute urine and actively pump in Na ions, the Cl ions are taken in passively due to their association with the Na ions. The opposite is true for marine fish, who actively drink water and then excreate the salts. But the short answer is fish do not get thirsty.
yes they do because some live in salt water and its makes them lose moisture, which makes them feel de-hydrated and they will have to drink to live!xoxo