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380G For Sale $3000 Acrylic tank & stand 300G Petrochromis Trewavasae and Tropheus mpimbwe Red Cheek & Duboisi 180G For Sale $1,100 Oceanic Cherry with Stand, T5HO Lights, (2) Eheim 2262 150G Tropheus Annectens Kekese & Ikola
You're reading that backwards, geoff. Osmosis moves water INTO freshwater fish through the skin and gills. The kidneys expel the excess water as VERY dilute urine; i.e., almost no salt loss from the body in the urine. Freshwater fish can urinate up to 30% of their body mass daily. The fluid in a freshwater fish, namely the blood, is has a much higher concentration of salt than the surrounding water. Osmosis tries to achieve balance of ions by pushing water INTO the fish and pulling minerals OUT of the fish. That's why freshwater fish have virtually no need to drink water. Osmosis is pushing water into the tissues through the semipermeable membranes of skin and gills.
Marine fish, on the other hand, drink almost continually to replace water that osmosis is pulling OUT of their skin and gills because the surrounding water is MORE salty than their internal fluids. Marine fish expel very little, highly concentrated urine to expel the salts that osmosis is pushing INTO their bodies.
Mark
What are the facts? Again and again and again--what are the facts? Shun wishful thinking, ignore devine revelation, forget what "the stars foretell", avoid opinion, care not what the neighbors think, never mind the unguessable "verdict of history"--what are the facts, and to how many decimal places? You pilot always into an unknown future; facts are your only clue.
Mark, I think we are talking the same thing on two different points.
Freshwater fish absorb water and do not have to drink it, salt water fish loose water and thus are always drinking the water.
But BOTH FISH TYPES produce Urine that is expelled thru the skin.
380G For Sale $3000 Acrylic tank & stand 300G Petrochromis Trewavasae and Tropheus mpimbwe Red Cheek & Duboisi 180G For Sale $1,100 Oceanic Cherry with Stand, T5HO Lights, (2) Eheim 2262 150G Tropheus Annectens Kekese & Ikola
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Urine leaves the body through the vent, not the skin. Anyway, the horse is dead...I'll quit beatin' on it now.
Mark
What are the facts? Again and again and again--what are the facts? Shun wishful thinking, ignore devine revelation, forget what "the stars foretell", avoid opinion, care not what the neighbors think, never mind the unguessable "verdict of history"--what are the facts, and to how many decimal places? You pilot always into an unknown future; facts are your only clue.
Looks like both are wrong, and that they have a common opening for Digestive and Urinary, so it would come out from the Anus and not the vent.
Lots of conflicting things going on, seems some say skin, others say gills, but most say anus.
380G For Sale $3000 Acrylic tank & stand 300G Petrochromis Trewavasae and Tropheus mpimbwe Red Cheek & Duboisi 180G For Sale $1,100 Oceanic Cherry with Stand, T5HO Lights, (2) Eheim 2262 150G Tropheus Annectens Kekese & Ikola
380G For Sale $3000 Acrylic tank & stand 300G Petrochromis Trewavasae and Tropheus mpimbwe Red Cheek & Duboisi 180G For Sale $1,100 Oceanic Cherry with Stand, T5HO Lights, (2) Eheim 2262 150G Tropheus Annectens Kekese & Ikola
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