PlanetCatfish.com

I have been reading Ian's Cory ID book and Shane's Venezuelan trip report, and both mention that some wild caught corys look different after they have been in captivity for awhile. Ian mentions this with regard to C. acrensis and has pictures to accompany it; Shane mentions it in regards to three varities of C. aeneus here: http://www.planetcatfish.com/shanesworld/207.PHP where he mentions that all three varieties are the same emerald green in the wild.

My question is: What do you think causes this color change? I have some ideas, but I would like to hear what others think.

Cheryl

I would imagine the color changes in Corys could be due to the natural sunlight in the wild and the types of food which are not available in the aquarium.

Mark

I'm afraid I don't know how 'unclear' the water is in Cory Land. But maybe it's a Bio-luminescent sort of thing, that allows them to recognise each other, and keep the 'shoal' together. If it functions like many other critters, who can alter their 'color shade', perhaps it can be 'powered down', when they're in clearer water?

Hello,

pictures from wild caught often show specimen above the water "on free air", under these light conditions they look somewhat diffent....and very often more "greenish"

My Brochis look out of the water dark green, somewhat like "britsh racing green" of some cars. Under water in the tank they are very much lighter green (see link above).
Feeling bad, they turn to an dark olive....

But there are also color changes under water in captivity for corys. They aren't so green or loose their greenish hugh.

Feeding more crustaceens food will often enhence color. Adding cyclops eeze to frozen food, much cory get a distinct greenish hugh. C.hastatus will show a greenish touch after about two weeks, sychri takes a little longer ...and Brochis more than a month. But just a few day for losing it....
And all dependend on "light and shadow", from which angle lights fall on it or you lokk at your fish.

Another influence is from the buttom...
One dark (black) sands (basalts) Brochis looks anything but not "splendens"....give him a light sand, he will look bright green:
http://coryforum.de/CorybilderDB/splend ... ens_JC.jpg

So it might be a mixture from food supply and light conditions (incl. colors of the ground), and probably by the setup of taking a photograph, e.g. flash light.