Why are Wild Red Devils brightly colored?

RD.

RD.

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While that is generally true with many species of fish, Matt, the waters of the great lakes in Nicaragua being as turbid as they are, won't allow UV rays to reach the fish beyond a few inches in depth, so sunlight can't be a factor in this case. It becomes a case of genetics, which makes sense if you consider how bright in color many of the gold/white (creamsicle) morphs are in captivity, fish that recieve zero sunlight. There are plenty of amphs that I have seen over the years that almost glow in the dark, and yet have never seen the light of day hit their skin.

With regards to diet: http://www.ncbi.nlm.nih.gov/pubmed/20151818

Testing the carotenoid trade-off hypothesis in the polychromatic Midas cichlid, Amphilophus citrinellus.

Abstract
Many animals use carotenoid pigments derived from their diet for coloration and immunity. The carotenoid trade-off hypothesis predicts that, under conditions of carotenoid scarcity, individuals may be forced to allocate limited carotenoids to either coloration or immunity. In polychromatic species, the pattern of allocation may differ among individuals. We tested the carotenoid trade-off hypothesis in the Midas cichlid, Amphilophus citrinellus, a species with two ontogenetic color morphs, barred and gold, the latter of which is the result of carotenoid expression. We performed a diet-supplementation experiment in which cichlids of both color morphs were assigned to one of two diet treatments that differed only in carotenoid content (beta-carotene, lutein, and zeaxanthin). We measured integument color using spectrometry, quantified carotenoid concentrations in tissue and plasma, and assessed innate immunity using lysozyme activity and alternative complement pathway assays. In both color morphs, dietary carotenoid supplementation elevated plasma carotenoid circulation but failed to affect skin coloration. Consistent with observable differences in integument coloration, we found that gold fish sequestered more carotenoids in skin tissue than barred fish, but barred fish had higher concentrations of carotenoids in plasma than gold fish. Neither measure of innate immunity differed between gold and barred fish, or as a function of dietary carotenoid supplementation. Lysozyme activity, but not complement activity, was strongly affected by body condition. Our data show that a diet low in carotenoids is sufficient to maintain both coloration and innate immunity in Midas cichlids. Our data also suggest that the developmental transition from the barred to gold morph is not accompanied by a decrease in innate immunity in this species.
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So while diet will always play a role in a fishes overall coloration, with fish from the midas complex most decent quality commercial foods will provide more than enough carotenoids to keep ones fish looking as colorful as they are found in nature.
 
RD.

RD.

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And to add to that .......

http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1022&context=ichthynicar


"Most Midas cichlids are of the normal cryptic coloration, but about 7 to 10% are brilliantly colored. These bright morphs lack the species-typical markings and have lost the ability to change their patterns; they range in hues smoothly from white through yellow, orange and red, though yellow through orange prevail. All start life normal in color, but at highly variable ages they lose most or all of their melanin, revealing the bright hues that most of them possess. The degree of development of this xanthomorphism varies among the lakes and appears to be positively correlated with turbidity of the water."
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According to some of the earlier work peformed by George Barlow, gold morphs are most abundant at deeper depths, and in more turbid water. Lake Masaya has very turbid water, and gold morphs are very abundant in this body of water. Lake Apoyo has quite clear water, and while the gold morph genes are present in the fish, no true gold morphs are found. The fish in this lake have the typical spotted & barred patterns.

So clearly in this case color can't be related to UV rays.
 
RD.

RD.

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You can breed the hell out of an amphilophus and still produce fry with great color. Some of the farms in Florida have been using the same breeding stock forever.
 
D

dogofwar

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While not all orange red devils are found at depth (for example, I'd assume that the glowing orange ones that Jeff Rapps recently brought in were caught at shallow depth vs. caught hundreds of feet down and decompressed), exposing them to outdoor sunlight will make their colors become more intense.

Great examples of glowing orange midevils - presumably from F1000 hobby stock - from shallow ponds in Hawaii: http://www.monsterfishkeepers.com/forums/showthread.php?240013-Feral-red-devils

There are lots of pics of glowing orange midevils in Florida lagoons - presumably also from released farm stock.

Put some red devils - or most any fish - out in a pond over the summer. They'll develop amazing colors. Better than they will inside.

It's the sun...

Matt
 
N

newworld

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Matt is right on regarding sunlight,experience I can say sun has done wonders for fish colors for fish I keep outside in the warm months, I can also say I caught amphilophus in Nicaragua in deep and shallow water with bright colors, while in florida I caught them in shallow water showing bright colors, here are some examples of fl "devil"....http://www.monsterfishkeepers.com/f...82463-Catalog-of-Miami-Red-Devils-(2-Viewing)
 
the animal guy

the animal guy

Arapaima
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First Genetics. If the fish is meant to be red or yellow or white; what they suppose to be
then it is the food they choose to eat.
then it is sunlight.
then it is their environment creating their mood and that controls color intensity.
 
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