Variation on colors and patterns of fish wesee in our aquariums, most likely collection area differences, or how they react to conditions in the tank?

[Magnum Man]

Of course this would concern wild caught, or pure strain breeds… in short, how much variation is environmental, and how much has to do with the actual collection location???
So many tank conditions, I would think could effect coloration, and patterns… water conditions, tank colors, of substrates and hard scape, plants, lighting, other tank mates, breeding or pairing…

I was looking at my Cupid cichlids this morning, and their “targets” look a lot like human eyes, and was thinking about groups of pictures on the www. And there is so much variation in coloring

 

[Magnum Man]

These are mine this morning… not the best of pictures ( but I’m working on that ) but strong eye spot, and nice colors on their pectoral fins

 

[GaryE]

The eyespot would be confusing to predators who might miss their target as they attack the wrong eye. It's really a common camo pattern.

Killies will breed true to location, and will Cichlids isolated in small streams. A lot of smaller streams are cut off by ridges, mountains, etc. They can be stable for very long periods. You'll get variation in places that flood as new fish join the gene pool. but stable streams often develop their own colour morphs.

With Pelvicachromis kribensis Cichlids, they can even be different to breed depending on where they were caught and how they've adapted to the local water conditions. And sometimes, with some killies, it seems almost identical looking fish from different localities are different species that can't successfully cross.

My big for fun fishkeeping project is a killie named Aphyosemion zygaima. I have a population collected in 1989. I got them in 1992, and I still breed them. I recently bought eggs from the first new importation of the fish since 89, caught by hobbyists in 2021. So far, as they colour up, they seem identical to my captive bred ones, even after quite a few generations. It's something I've seen with a lot of killies - very set colour, marking and fin patternings depending on their DNA, and not how we keep them.