Originally Posted by
MattH2181
http:///forum/post/3142994
well you need to take into account that fish dont have the same complex eye structure that we have. i cant say what they are seeing because i dont know, but its not the exact same thing we see.
On the contrary, it actually could be better and see things we we could only dream of. I gave at a shot at saying 'what fish see' before;
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That's a very broad question, but in a short, yes, some fish do see color, some don't. Catfish, for instance are colorblind. To see, the eyeball is made up of 'rods and cones.' (
Wiki link). The rods are sensitive to light, help with 'brightness' of an object (also help see in 'low-light' conditions), as well as motion. Cones help see color and help see in daylight conditions. Almost every type of eye has many, many rods. Cones are limited, the human eye only has 3, which allows us to see about 300,000 different colors. Each cone makes up a different spectrum of light. Long wavelength, medium, and short. So when the eye sees a red object (long wavelength), it reacts to it.
Here's where it gets cool with fish. The catfish example, they have zero cones, and are completely colorblind. However, most predatory fish, have at least 3 cones, some with 4 or even 5 cones. So they are able to see colors we can only began to imagine, and some fishes vision also extends into the UV light spectrum.
One final thing to consider and that almost every fish has it's eyes on opposite sides of it's body, and therefore doesn't have the 'binocular vision' like humans have. The basic understanding is that they see more or less two distinct images, that overlap a bit. Therefore most fish have poor distance vision, but see very well close up.
Unfortunately, research pertaining to common aquarium fish, is limited at best. If I had to guess, I'd say most marine fish have far superior vision (like almost everything else) to their freshwater counterparts, and have at least 2 cones (damsels and clowns for instance). As where fish that depend on color, angels, etc, might have 3 or more? I'm straight guessing here though. %%
As far as 'vibration' that is handled by the fish's lateral line (a sixth sense we don't have). Wiki's intro is better then I could do
In aquatic organisms (chiefly fish), the lateral line is a sense organ used to detect movement and vibration in the surrounding water. Lateral lines are usually visible as faint lines running lengthwise down each side, from the vicinity of the gill covers to the base of the tail. Sometimes parts of the lateral organ are modified into electroreceptors, which are organs used to detect electrical impulses. It is possible that vertebrates such as sharks use the lateral organs to detect magnetic fields as well (along with Ampullae of Lorenzini). Most amphibian larvae and some adult amphibians also have a lateral organ. Some crustaceans and cephalopods have similar organs
http://en.wikipedia.org/wiki/Lateral_line
