The Cat Fish Chomp

[juggler]

This has nothing to do with ornamental catfish, but I thought that some of you breeders and "catmen" might be able to help this fisherman. I always wondered why, when taken from the water, catfish start chewing and bitting the air like mad. No other fish that I know of does this. Is there a logical reason, that anybody knows, that they do this? Blue cats seem to be particularly enthusiastic when it comes to this behavior.(Don't worry, even though I did catch some 7 pounders I threw them all back. I'm just nice like that.)

[Silurus]

The fish are gasping to breathe (all fish will do that when taken out of the water) and with a depressed head, it would seem especially so that the fish is biting.

[juggler]

Your reply made me think. All fish do not gasp in the same manner- bass in particular simply gape wide and remain with their mouths open. A reason that cats gasp so much could be becuase their tighter and deeper gill structure allows no air to circulate past them without active motion whereas other fish need simply open their mouths to let water(or, instinctively, air) flow past. Don't cats seem to breath differently than that most other fish while in the water(they fill their mouths with water and then close and force it through their gills and others just open their mouths and gills simultaniously to let water pass by)? Thats one of my theories, any holes in it?

[Silurus]

You're pretty much close to the truth. Catfishes make little or no use of ram ventilation than more actively swimming fish (like bass), and so have to open and close their mouths more frequently to pump water through the gills.