Why are saltwater fish more colorful than freshwater?

[Sati]

Why are saltwater fish most always more colorful and more bold looking than freshwater fish?

This many sound like a silly question, but I'm wondering what the answer is. Both live in sunny, warm water. Maybe somebody has some good reads on this topic? Thanks.

[gooyferret]

Hmm havent read anything in relation to colors of the fish but IMO i would have to say that SW is more of a colorful enviroment with corals etc... With that in mind i would think that fish would try to blend and addapt to their enviroment.

[lmw80]

I think it also has to do with the way saltwater reflects/refracts light and colors versus freshwater.

[Catalina]

this is a very interesting question. i'd be interested in seeing more thoughts on it. i agree with gooeyferret that it must have something to do with the ability of the fish to camouflage with all those colorful plants and coral. freshwater fish have a lot fewer colors to blend in with. i wonder if there are any other reasons, though?

[Sati]

lmw80, when you take the fish out of the water and photograph then in your hand they look the same.

As far as camouflage, I can agree with that somewhat. There is still seaweed and sand that is similarly neutral to FW. It's not as though the fish completely chameleon-like though, because you see many fish in the same area with very different and bright coloring. Yellow, blue, white, red, black, green, orange. Land animals, other than many tropical birds seems to blend in far more than SW fish, I'd say.

Is there any way to mirror this post on the SW forum?

[e-cat]

ask reefrunner or some one else too move this too a SW forum, you wil have a better chance too finding an ansewer, BTW good question.

[Allivymar]

Actually I think its a matter of opinion. I personally don't think SW fish are more colorful overall. Think about apistos, bettas, gouramis, kribs, salmon, etc, and you'll realise theres an awful lot of very colorful FW fish. Conversely, theres an awful lot of boring colored SW fish; sardines, many adult damsels, sharks, smelts, etc. I do think some SW fish have more intense coloration, but the variety of color in both are extremely varied.

What I think the difference is, is most of the aquarium SW fish sold are reef fish, who live in areas with lts of color (think of corals and anenomes); if you include most of the other SW fish from different areas, you'll see overall there isn't a lot of colorful SW fish.

[snapcrackler]

I agree Alli, that's a splenderiffic point.

And it's almost as though it's another color "pallet", a different color theme for FW animals, as well. Super brilliant and contrasty colors exist in FW and yet they are somehow a little different, in a neat sort of way. SW stuff seems painted, FW stuff seems airbrushed.

Some may speculate that since animals adapt to their surroundings (bright corals in reef territory) then you tend to find animals that end up being a little brighter since they are around brightly colored corals and stuff (I know, what makes the corals brighter?)

However, that's a bit of an evolutionist's speculative viewpoint and assumes at least partially that at one time, these fish were not bright and colorful??? Poop.

[Sati]

Don't get me wrong, it's not about which I like better. I love FW fish. I know there are dull SW and vibrant FW. Show me a fish like this or one of those scrumptious little hot pink fish in FW and then I might believe that SW aren't more colorful.

[img]ftp://sati%40ourglasshouse.com:p00p33@66.98.134.33/public_html/holly/04-12-03_spotted_mandarin.jpg[/img]

[e-cat]

good points allivymar, theres nice bright and dull colors in both worlds, but i dont think SW would lose a color contest too any FW fish.

[snapcrackler]

How about this nice pond fish, the longear sunfish? 8)

(Image source: www.conservation.state.mo.us)

[possum]

those make pretty good aquarium fish as well i had a 55 with them in it and they were some of the most interactive fish i ever had! and i caught them myself LOL

[stoneydee]

I agree that it is probably to blend in with the environment. Think about where most of the FW fish come from - rivers and lakes, thus the lighter colored undersides and darker, more earth toned topside. As previously noted, a lot of the SW fish we see are reef fish, where the corals are brightly colored.

All in all, most of any fish's day is spent looking for food - and avoiding being eaten. Blending in with your surroundings make you much less of a target. 8O

[snapcrackler]

Agreed stoneydee!

hehe cool possum, I grew up next to a pond and caught a few of my tank inhabitants as well.....

[possum]

Man i go to the lake and just scoop with my net and catch all sorts of cool stuff!!

loads of grass shrimp for the fish to eat too

[e-cat]

Originally Posted by snapcrackler

How about this nice pond fish, the longear sunfish? 8)

(Image source: www.conservation.state.mo.us)

nice looking fish but a miniatus grouper has got it beat

[BrianNY]

Great question!! IMO SW tropicals have brillaint intense coloration. Not so for temperate water SW fish. If you think about the number of species that exist in the tropics (not just fish but birds, reptiles, mammals), they are almost all very colorful. And I think it has more to do with recognizing their own kind, and attracting a mate then anything else.

Perhaps the reason FW tropicals don't have the intense coloration of SW has to do with the clarity of the water they are from. South American rivers and streams are murky, whereas the waters of lake malawi must be clearer. Just a thought.

[Madame_X]

Killifish are extremely colorful freshwater fish. For example:



That's an aphyosemion australe. There are other equally (or even MORE) colorful killies.

[madasafish]

First: *Sati* I don't think Lori meant that salt water itself makes the fish look brighter, I think she meant that fish have adapted differently to light conditions over billions of years because of different refraction/diffusion properties of salt water.

My opinion is that it may have to do with *pH* and dissolved metals. Just a hypothesis, and not one that's supported by all instances (e.g. Lake Victoria). I'm wondering if the ions present in saltier/higher pH water enable the fish to brighten their colors. Prime examples of this apart from the oceans are Lakes Malawi and Tanganyika. This may be an issue of difference in water/light properties or a biochemical difference.

And though I agree with Alli in principle, I've still gotta say that if you walk into a fish store with FW on one side and SW on the other, you've got a huge difference in brilliance of coloration. Though fish like killies, cardinal tetras, bettas, clown loaches are colorful, I believe FW fish are a little less vibrant. Are they less cool as a result? Certainly not!!! I'm much more interested by the morphology, breeding habits, behavior of FW fish!

No FW inferiority complex here--I'm very happy with my fish!

[TheNewGuy]

If I had to guess. I would say that SW fish have had millions of years to develop and as you may know a fishs' colors are mostly for attracting mates (most fish not all) and over this long period through evolution the fish have developed very vibrant colors (survival of the fitest).