Why are saltwater fish more colorful than freshwater?

[BrianNY]

Did you know that fish first evolved in FW? The move to brackish and then SW was a later developement.

 

[MT79]

Can you give a link etc. to further substantiate that statement? I'm very interested.

 

[gooyferret]

Did you know that fish first evolved in FW? The move to brackish and then SW was a later developement.

I dont agree with that statement and would like to see where it came from! IF you believe in evolution which i may and may not im not sure, well that cant be true! Just for the fact is evolution believes that the world at one time was a mass of water after the melt of the ice age....and you dont see FW fish in SW oceans.

I believe and this is my opinion on top of what i wrote in my first reply is that I believe its for survival. Someone stated that "survival of the fittest" but he said it was for mating. Survival is refered to LIVING. We all know that most fish dont breed overly often with a couple exceptions. Lets all look at the Powder Blue as an example one of the most colorful and beautiful fish. Theirs a few major colors white, black, blue, and yellow.
These colors i believe are in certain spots for camoflage, blue is mostly the body blend with the water more easily, yellow corals and black night. Fish also tend to lighten in color during the night, possible for the fact to blend in more. Lawnmower blennies for example can vibrate their colors (have seen mine do it) not drastically but a little. An octopus can change colors to blend into its surrondings and the list keeps going on.

 

[MT79]

I'm sure vertebrates, including fish, first evolved in the ocean in the ordovician period (about 500 million years ago). That's why I would love to read something that's states otherwise. I'm not trying to offend BrianNY, just curious where that info was obtained.

 

[snapcrackler]

I believe in creationism y'all 8)

The "millions of years" thing never happened on this earth.

Anyway here's one of the links I like regarding this subject.

http://www.creationism.org/topbar/creationism.htm

 

[MT79]

8O riiiiight. proof shmoof. Tangible facts, what do they mean.... EVERYTHING.

 

[snapcrackler]

MT, my best friend is a chemist, he doesn't side with most of those views either.

 

[MT79]

what does that mean? B/c he is a chemist he understands the universe? Einstein is famous because he TRIED to, but he couldn't explain everything. Sum up in your own words what a "creationist" believes in. Help me understand.

 

[BrianNY]

Hey not to worry, I'm not offended. Debate is healthy. I didn't mean to retry Scopes either (lol).

Where did I get my info for such a brash statement? Every Monday evening there's a program on the Science Channel called "Prehistoric Planet". I recommend it to anyone interested in our worlds natural history. This is where I heard it. I'll try and and find something further to substantiate the claim that vertebrate evolution began in FW.

As for creationism vs. evolution, I find the argument for evolution too compelling to simply dismiss it. So would most bioligists IMO. People being people will believe what they feel comfortable believing.

 

[ferret]

This is just my own suggestion, but I think this thread is taking a turn towards a different tangent. This debate of creation vs evolution was on another forum I visit (Not even aquarium related) and reached well over 1000+ posts. If this debate is to continue (And so far its peaceful and without flaming) I would suggest a new thread be created. I don't care if its debated or anything, just this is the wrong thread for it.

In other news...

My personal opinion is that they simply have different environments. That's it. Desert lizards are tans, jungle lizards are greens. Fish living in bright colorful reefs are bright and colorful. Fish living in rivers and streams with sandy/muddy bottoms and lower light levels are darker colors (Note: I used darker, not dull)

 

[snapcrackler]

what does that mean? B/c he is a chemist he understands the universe? Einstein is famous because he TRIED to, but he couldn't explain everything. Sum up in your own words what a "creationist" believes in. Help me understand.

Hehe... what I meant was this:

My friend does not believe fully in my creationist views. He tends to side more with you, MT79. He's obviously a smart cookie too.

We're still best buds because I don't take offense from his views, and he doesn't take offense from mine.

Peace??

 

[MT79]

Absolutly Snapcrackler , I enjoy a good debate! Like BrianNY said healthy debate is, well, Healthy! Now back to what the thread is about....

 

[madasafish]

Wow! I saw that argument spiralling out of control in my mind... but what a resolution! That kind of healthy approach typifies this site. Nice!

(Scopes aside... ) I think the matter of whether fish evolved first in FW or SW (our present conception of FW and SW) is moot. When fish (i.e. in this case vertebrate sea creatures) first came into being during the Cambrian Explosion (about 530 mya), water conditions were hugely different than they are at the present. Heck, the continents as we know them didn't exist. What I am sure of is that these creatures first occured in the large oceans that surrounded pre-Pangea. Not necessarily SW (as we know it) oceans, though...

So, I think it's not quite correct to say that marine fish have had more time to develop, because FW fish are almost certainly off-shoots of a common ancestral group of Cambrian vertebrates. After all, FW and SW fish didn't spontaneously come into existence in the two environments. Morphology (body shape) is sufficiently similar (look at FW Angelfish torsos and SW batfish torsos) to indicate common ancestry...

And, salinity and other ion concentrations in the world's oceans have changed hugely over even the last thousands of years (deglaciation causes a freshening of the seas, glaciation an increase in salinity), so I think it's fair to say that fish have had to adapt in all environments to changing conditions quite regularly over history.

I tend to agree with TheNewGuy's statement that a fish's coloration is dependent upon the environment it lives in. Is this a cop-out, just another chicken-and-egg argument? I don't think so... The coloration of their environment, mainly the plants and other primary producers around them do vary in color depending upon the minerals and light available to them. How do I explain neon tetras??? Their brilliant blue could well imitate the color of reflected light that bounces off of the rivers they live in. This could be a poweful adaptation to protect them from wading and diving birds. Also, given the fact that light is refracted under water and shimmers, this could be an added protection from predatory fish underwater--a predator could believe it was seeing a reflection of light, not prey.

Just some ideas...

 

[ferret]

To add to madasfish's post.. I've read that the neon's blue strip is actually to help find each other in the dark environments they live in. Neon's generally live in small streams and such in SA, under dense jungle canopies that let very little light in. The flash of blue is supposively a form of identification.

 

[BrianNY]

Are you ready guys???

The first vertebrates were jawless fish of the class Agnatha which includes present day lampreys and hagfish. The actual species was a fish called Ostracoderm which was mainly a FW fish dating back to the Cambrian. It became extinct at the end of the Devonian some 350 million years ago.

www.askjeeves.com, type in evolution of fish