It almost goes without saying that everyone loves brightly colored fish, but many fish owners don't realize that those colorful fish do not come by their brilliant hues naturally. Juicing, or artificially coloring fish using paints and dyes, has become quite widespread in the aquarium trade. Yet most owners are unaware that their fish have been altered. You might be surprised and appalled, to discover which fish are artificially colored, and how it's done.

How It's Done

Several methods are used to alter the color and appearance of tropical fish. Coloring fish stresses them and makes them more susceptible to disease. Young fish that are not fully grown are often stunted by the painting process. Others are not killed outright, but contract disease as a result and die later.

Some methods result in mortality rates as high as 80 percent. Many of the survivors will have an abbreviated lifespan. Nine out of 10 painted fish will lose their coloration within a matter of months.

Colored Food

Young fish are fed treated foods that will temporarily tint them. Once they are no longer fed the treated food, they eventually lose their color. The dye they consume can negatively affect their growth and development.

Dye Injection

Needles are used to injecting dye under the skin. Because only a small area is affected, the fish must be subjected to many punctures to achieve the desired effect. The popularly painted glassfish are dyed this way, using fluorescent colored paints. Another recent fad is to use dye injection to tattoo patterns, such as hearts, on the fish. Fish that are injected often contract infections from the puncture sites.

Dipping

As barbaric as dye injections seem, this practice is even worse. The fish are first put into a caustic solution that strips off their protective outer slime coating. They are then dipped in dye, or injected with dyes, after which they are dipped in another chemical that irritates the flesh to stimulate re-growth of the slime coat. This method is stressful and has a high mortality rate.

Painted Glassfish

Created by dye-injecting the nearly colorless Indian Glassfish (Chanda ranga), these are one of the hottest selling and most brilliantly colored of the juiced fish. Their lack of color makes the fluorescent paint used to color them stand out clearly. Although the color fades over time, it lasts long enough to catch the eye of unsuspecting customers. A large percentage of glassfish die during the painting process, and those that survive are extremely susceptible to infections.

Fruit Tetras

Created by dipping the white skirt tetra, an albino morph of the popular black skirt tetra. These are usually painted pastel colors and given fruit names such as strawberry tetra, blueberry tetra, grape tetra, or simply mixed fruit. Some marketers have gone so far as painting the fish special colors for holidays. For example, the red and blue dye is used to create a patriotic colored fish for the fourth of July. Orange dyed versions are sold with naturally colored blackfish during the Halloween season.

Jelly Beans and Bubblegum Parrots

These are painted versions of the blood parrot, a fish that is created by crossbreeding certain species of cichlids. The hybrid fish are dyed bright colors, such as blue, purple, green, and red. Like other dyed fish, many do not survive the process, and those that do often have a damaged immune system.

Other Painted Fishes

Albino Oscars are injected with dye to give them a brilliant blue color. Recently additional colors have appeared on the market, similar to the jelly bean parrots.

To make them more attractive to potential buyers, some corys are now being injected with dyes to color their tail or other parts of their bodies.

Even though blue botias exist in nature, dyed specimens are now appearing on the market. They are dye injected to create a more brilliant blue, apparently to enhance their sale.