I remember when I was younger we had aoscar and koi together. Over time, you may notice a change of colour. Tropical food makes a red toned pigment appear in goldfish.
A Mottled, dark, and gold morphs on light substrate. Although they demand high water quality think cannister filter ,and can be picky eaters, Discus fish are gorgeous and demand high tank temps, like 86 degrees. Betta Advice For Beginners. If the scale of variation is large and greater than the dispersal range of the species, a population will only experience one set of conditions and would benefit from adapting to that condition Michie et al.