because some fish aren't adapted to well.
ones that don't don't need on
Increases the fish's volume by filling the swim bladder with oxygen.
The ray-finned fishes are characterized by having fins supported by bony spines or rays. They also have a skeleton made of bone, scales covering their bodies, and a swim bladder for buoyancy control. Ray-finned fishes are the most diverse group of fishes, with over 30,000 species.
Nobody knows the exact number of known species of deep sea fishes. There are too many species that cannot all be listed. The most deep sea fishes are yet unknown.
Correct
Men face Urge urine incontinence very often in which the bladder tries to empty despite best efforts to restrain leaking. There is a lack of co-ordination between impulses the brain gives to the bladder and what the bladder does. It leads to huge losses of urine and increase in frequency of urination.
Fishes of corse any kind of fishes !
Gills
Salmon and Tuna are most known fishes for yielding the fish oil.
Their is an air chamber in most fishes just like in submarines. When it gets filled with air the fish moves up. While, when air is released the fish moves down. This is precisely what happens in a submarine.
Bony Fishes
Swimming
Epithelial cells are the most common cells of the bladder wall.