Cardinal tetra
The characid has bright red ventral elements Associate in Nursingd an iridescent blue line that runs horizontally down the length of its body. The characteristic opalescence of this and connected fishes, like the element characin fish, could be a structural color, caused by refraction of sunshine among purine crystals that develop among special cells referred to as iridocytes within the connective tissue layer. the precise shade of blue seen can rely on the viewing angle of the aquarist relative to the fish - if the aquarist changes viewpoint therefore on verify the fish a lot of from below, the color can modification hue, turning into a lot of deeply sapphire blue and even indigo. modification the point of view to at least one higher than the fishes, however, and therefore the color becomes a lot of green. Cardinal tetras seem to grow larger in captivity than they are doing within the wild. they need an outsized abdomen and tiny gut.
