2007-01-02 04:59:00 · 4 answers · asked by knowssignlanguage 6 in Science & Mathematics ➔ Zoology
Water contains all sorts of dissolved gases. Oxygen is one of these. Gills allow fish to absorb the oxygen from the water, and excrete carbon dioxide.
2007-01-02 05:03:45 · answer #1 · answered by TimmyD 3 · 0⤊ 0⤋
It is the not the water the helps a fish breath, but the structure of the gills. The gill have many tiny folds on them to increase surface contact with the water. The blood vessels within the gills are also arranged so that maximum oxygen uptake is achieved. The water itself can dissolve only so much oxygen, making only so much oxygen available to a fish. This availability depends on temperature of the water and other dissolved particles. Increase in either of those two factors decrease the amount oxygen available to fish. Fish, as a group, indeed have some other a variety of other adaptations (anatomical, physiological, and behavioral) that helps them extract oxygen in a variety of environmental conditions that can limit O2 availability.
2007-01-02 13:09:28 · answer #2 · answered by Ruben Z 2 · 0⤊ 0⤋
Water contains roughly 5% oxygen. Which is all fish need to survive. The breath it using their gills which work extremely similar to lungs. Humans need around 18% oxygen to live, so if you were to over oxidate water to around 18% you could actually fill your lungs with water and breath like a fish. I read once that they had once consider doing this for premature babies (because their lungs dry out), but people thought it was inhumane.
2007-01-02 13:06:41 · answer #3 · answered by Wesley C 3 · 0⤊ 0⤋
That's where life began - then there was creation to breathe air.
2007-01-02 13:48:03 · answer #4 · answered by K 2 · 0⤊ 0⤋