The fish danio rerio belongs to the so-called model organisms of developmental biology. Due to the simplicity of maintenance, reproduction, high speed of embryo development it has become a kind of laboratory white mouse for ichthyology. It is one of the few living organisms that have visited space orbit.
Swordtail
Swordtail is a bright red-colored mobile aquarium fish with an original tail shape. Inhabitant of the waters of Southern Mexico and Guatemala. Its name is owed to the sword-like outgrowth on the tail fin of the male. Natural coloration is green. Red fish with a sword-like outgrowth on the tail is the result of the work of breeders.
Guppy
Guppy perhaps the most famous aquarium inhabitant. Many aquarists began to familiarize themselves with the wonderful world of the aquarium just by keeping these fish. This is understandable. They are very unpretentious and beautiful, especially the males with their tails similar to gypsy skirts.