what does Brightly colored red gills in a fish indicate?
106603
I believe it means that they are very healthy.
576886
Is fish red by light? Pleeez help me, so inpotant!!!\nHow's that?
14422
Unfortunately this is a sign of disease in fish. It usually comes before their death. You could try an antibacterial remedy.
38622
Blood is\nalways red: bright red when it is oxygenated on the arteriolar side of our\ncirculation, and deep red when it is not oxygenated on the venous side.
82203
Fish can often be seen gulping air from the surface during heat waves when oxygen in the water is depleted, other fish eat from the surface
517409
Fishes have well-developed nervous systems that organize around a central brain, that is divided into different parts. The most anterior, or front, end of the brain are the olfactory bulbs, which are involved in the fish's sense of smell. Unlike most vertebrates, the cerebrum of the fish is primarily processes the sense of smell rather than being responsible for all voluntary actions. The optic lobes process information from the eyes. The cerebellum coordinates body movements while the medulla oblongata controls the functions of internal organs. Most fishes possess highly developed sense organs. Nearly all daylight fish have well-developed eyes that have color vision that is at least good as a human's. Many fish also have specialized cells known as chemoreceptors that are responsible for extraordinary senses of taste and smell. Although they have ears in their heads, many fish may not hear sounds very well. However, most fishes have sensitive receptors that form the lateral line system. The lateral line system allows for many fish to detect gentle currents and vibrations, as well as to sense the motion of other nearby fish and prey. Some fishes, such as catfish and sharks, have organs that detect low levels electric current. Other fishes, like the electric eel, can produce their own electricity.
126853
I think fishes get thirsty if there is not enough oxygen in the water.
32854
Fishes, as all other vertebrates, have closed circulatory systems; they have a single blood circuit in which the heart pumps the blood toward the gills where it picks up oxygen, and is then distributed to the body. However, our (human) anatomy is very derived with respect to aquatic pisciform vertebrates. In fishes the circulatory system is very symmetrical and more metameric. The best place to look is the gill area, where the major vessels occur. The heart, which looks like an elongated bulb, is situated ventrally right behind the gill basket. The ventral aorta is the major vessel extending forward below the gills, and emits branches to each functional gill. Once they go through the gill filaments, these vessels reunite dorsally and form the dorsal aorta (paired, then joined). Other vessels are difficult to observe as they usually collapse in dead materials, but if you have fresh large specimens you could try injecting a colored rubber solution (VERY carefully) inside the largest vessel you can find and if the walls are not broken, you will get an internal cast of part of the system. \nAlso look for the dorsal longitudinal vessels that are really close to the vertebrae, passing through the haemal arches.
742768
The Red Sea got its name from a phenomenon caused by a type of algae called Trichodesmium Erythraeum, which is found in the sea. When these algae blooms die off the blue-green color of sea appears to change to reddish-brown color. \n\nIt's not always red, just when the algae dies off.
858632
Typically rocks with a reddish color have a high content of iron.  The color is essentially iron oxide (rust).
871649
That is a very interesting question.\nno . . . . but there is one exception\nIn a camera flash, the light is reaching through the pigmentation\nto the retina, the light-sensitive membrane covering the back wall of the eyeball, which is the color red.\nthe only organisms that have eyes visibly red are ones that are albino\nalbino organisms have less melon(color) in there skin, hair, and eyes.\nresulting in the clear vision to their retina, which causes their eyes to be the color red.\n(i.e. white mice that have red eyes)
497932
The chalky-white paste called urate (made of uric-acid crystals) is a byproduct of bird kidneys. What you actually see is the color of the whitish crystals. Swimming in urate is a chunk of stool (solid waste). This piece is usually hard and worm-like, and gets its color from the bird's diet. Hues range from greenish for birds who feed on plant seeds and green vegetables, to brownish for brown birdseed, and reddish for strawberries. For shrimp-eating seabirds, it's pink!\nTo top it all off, bird poop contains a tiny sprinkle of urine. Why so little? "Aside from the ostrich, birds don't have bladders and can't carry a lot of water around. They'd be too heavy to fly," explains ornithologist (bird expert) Jerome Jackson at Florida Gulf Coast University. (By the way, the ostrich can't fly.)\n\nThink bird poop is just waste? Think again. Veterinarians see it as an indicator of bird health. Abnormal colors like red urine and urate may be signs of internal bleeding. Brown urate may signal lead poisoning, and green or yellow urate may mean liver disease. Colorful indeed!
853162
this is because gills of fish need a water flow through it so that the exchange of gasoues can occur
448554
they use gills. the gills are filled with lots of blood vessels.  the fish draws in water from the mouth, which passes by and out the gills. as the water moves by, the blood cells take in oxygen and the waste gases are released.
908467
Almost all vertebrates use the iron compound hemoglobin as the oxygen-transporting compound in their blood. Oxygenated hemoglobin is bright red, unoxygenated darker red. Many invertebrates use a copper compound rather than an iron compound to transport oxygen, so their blood is blue-green. I believe there is some arctic fish which also has blue-green blood, for the same reason.
123094
Bright red or dark red?  It depends.  Bright would indicate that you have some sort of cut or tear close to the "exit" point.  Dark may indicate that you have intestinal bleeding or other problem in the digestive system.  Don't leave it to guessing, get your doctor's opinion if you're having problems with bloody stool.
1118551
There are several vertebrates with blood that is green in color as a result of a buildup of the breakdown products of hemoglobin. This is a natural state for these species.