aquarium-fish artificial breeders breeding colorful colors colourful colours common community-fish differences fish freshwater-aquarium-species guppies guppy guppy-strains hardy jar live-bearing-species millionfish pattern-variations patterns peaceful plastic-vegetation poecilia-reticulata popular rainbow-fish shapes Sizes small-size species tank-water temporary-container tropical-fish variable-food-preference variations variety widely-distributed animal animals cat cats feline pet pets