Danyo hopra (firefly) appeared behind the glass of the aquariums of the world only in 2003. Nevertheless, has already found its regular adherents. What contributes to the simplicity of content, peaceful disposition, as well as a very beautiful coloring. This is the smallest fish of the genus. Its length rarely reaches three centimeters. And the usual size for her is about two and a half centimeters. As all representatives of the genus, she likes to stay in a flock. These mobile flocks look very spectacular in any aquarium with suitable conditions for these fish.
Danio rerio
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.