what fert... maybe a fish too?

I agree, the labyrinth organ is a back-up system in case Oxygen is short in the water. Even if the fish isn't consciously using its gills, and is relying on its labyrinth, the ammonia laden water would still come into contact with some parts of its gills. Gill covers protect them for the most part, but if they worked perfectly then fish would never get parasitic worms in their gills and what not.

:OT:
gingerinaustin, what a beautiful fish you have!!
 
gingerinaustin, what a beautiful fish you have!!
Thanks! He was beautiful, until his fins rotted off and he developed gill hyperplasia on one side. Hardy little fella that he is, he acts like nothing's wrong--swims, eats like a pig, flares at his reflection, does his little happy dance--but he looks terrible. Alas, he's had no fin regrowth despite pristine water conditions in a filtered, heated, cycled tank, six full cycles of different antibiotics, live foods and Betta Spa almond leaf extract. Despite it all, he'll probably outlive all my other fish, the raggedy little Andy.
:iagree: ...:topic: ! But the OP started another thread about his daughter's tank so I don't feel quite so ashamed.
 
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