Fish breath through their gills. Water enters a fish’s mouth, passes over the gills, and is expelled out into the water body. You can think of a gill as being a thin membrane. Small holes in this membrane allow tiny oxygen molecules in the water to pass through and into the fish’s body.

As the fish opens its mouth, water runs over the gills, and blood in the capillaries picks up oxygen that’s dissolved in the water. Then the blood moves through the fish’s body to deliver the oxygen, just like in humans.

Fish have gills that extract or take oxygen out of the water. Blood flows through the lamellae and filters the oxygen from the water and releases carbon dioxide into the water. After the fish gets its oxygen from the water, it passes out through the gill openings and the breathing process begins again.

Oxygen and carbon dioxide dissolve in water, and most fishes exchange dissolved oxygen and carbon dioxide in water by means of the gills. Water taken in continuously through the mouth passes backward between the gill bars and over the gill filaments, where the exchange of gases takes place. …

gills

Can fish cry? The cerebral cortex is neurologically, what allows us to produce tears, and this is unique to mammals alone. This means that, no, fish cannot cry. They lack both the mental complexity and the emotional depth.

Catch-and-release fishing is cruelty disguised as “sport.” Studies show that fish who are caught and then returned to the water suffer such severe physiological stress that they often die of shock. When fish are handled, the protective coating on their bodies is disturbed.

A fish hook or fishhook is a tool for catching fish either by impaling them in the mouth or, more rarely, by snagging the body of the fish. Fish hooks are normally attached to some form of line or lure which connects the caught fish to the angler.