Question about How Fish Sink and Float activity

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lds2010
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Question about How Fish Sink and Float activity

Post by lds2010 »

Greetings !
The article How Fish Sink and Float
explains the behavior of the balloon-bottle system.
But using these observations to explain the behavior of bladdered fish is completely wrong!
The article ignores a whole scientific literature dating back to the 60s [Root effect, rete mirabile, oval body etc.]
The example of the gas-free balloon that sinks the bottle and floats it when filled with air, analogous to the behavior of submarines [with water in the caissons], is absolutely not analogous to the fish-swim system whose behavior is of the quite the opposite!
Article it will seem strange but: bladdered fish pump air into the bladder when they descend to deep altitudes and reabsorb it to rise!
Inside the bladder. the gas pressure balances only the external hydrostatic pressure of the altitude in which it is located. In practice, the volume of the bladder can always be considered constant.
This said in a short, schematic way.
I invite you to remove your article from the site or leave it to explain the mass / volume ratio but don't talk about fish.

For updates, consult this book, old but brand new for you!
Comparative Physiology of Respiratory Mechanism - Academic Press -Johan B. Steen
Chapter 10 - THE SWIMBLADDER FUNCTION 1971 155-161 ; References 162-172
Lucio Di Stefano
Excuse my English!





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Re: Question about How Fish Sink and Float activity

Post by AmyCowen »

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