Fish and Oxygen
Date: Spring 2013
Do different species of fish require different amounts of dissolved oxygen to sustain their lives and is there a such thing as a body of water having too much dissolved oxygen for any one kind of species of fish to sustain life?
Thanks for the question. Yes, different species of fish are expected to require different amounts of dissolved oxygen. In principle, it is possible to have too much dissolved oxygen in the water. However, I have never been exposed to a real example of over-oxygenation with regard to fish. Over-oxygenation of water is important in the sewage treatment process as anaerobic bact
eria cannot grow in oxygen rich water.
I hope this helps. Please let me know if you have more questions.
Fish gills are extremely efficient in taking oxygen out of water and most fish can also breath some through their skin as well. Different fish species have different oxygen requirements and this explains why most species of fish live within one particular ecosystem. There has been no attempt to test if fish species has an upper limit of oxygen saturation because water can only hold so much of the gas in the first place. Fish for example the require high levels of oxygen generally live in fast moving streams where the agitated water maintains a high levels of oxygen or at least the most water at a given temperature can carry.
Gills are most efficient in transferring oxygen than lungs and most fish can regulate their intake needs. The issue with fish is not too much oxygen, but too little.
Thank you for your question.
Yes, different fish have different dissolved oxygen requirements. Trout for example require large amounts-this is why you will find them in cold streams that have turbulent water, such as water running over rocks. Also, colder water holds more oxygen, so they are usually found deeper in lakes during the summer when water is warm. Other fish such as catfish can live in warmer, more stagnant water. Spme fishermen know where to fish for particular species by using a thermometer.
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Update: November 2011