Vibrantly coloured fish is very popular among aquarists, and there exists a wide range of naturally colourful fish species. Even if you are a beginner aquarist, you can find striking fish species that will look great and add colour to your aquarium. If you make sure to keep the water quality at optimal levels, provide your fish with a stress free environment, and feed your fish suitable foods they will display their best colours.
Unfortunately for many fishes, artificially coloured fish have become increasingly popular in the aquarium trade. As mentioned above, the natural way of enhancing the coloration of a fish is to provide it with ideal conditions. Many fish producers have instead started to create colourful fish by injecting them with artificial colour or dipping them in dye. The so called Painted Glassfish that is commonly found in pet shops is for instance an almost colourless fish species named Indian Glassfish (Chanda ranga
) that have been injected with brilliant colours.
Problems with dyed fish
So, why is painted fish a problem? Well, it is cruel to the fish and
to the unsuspecting aquarist. The fish will of course suffer during the various treatments (you can read more about the details further down in this article) and also become much more susceptible to illness, which greatly reduces its lifespan. Some dyeing methods cause up to 80 percent of the treated fishes to die during or right afterwards, but since 20 percent survive long enough to be sold to aquarists the treatment is still profitable. In addition to being hurt and stressed, dyeing can cause young fish to be stunted and never reach their full size. The aquarist will purchase a stunningly looking fish that gradually looses its coloration as the dye metabolize. Estimations show that roughly 90 percent of these painted fishes loose their colours within a few months, but this is actually not the biggest problem. The main thing to worry about is instead the increased risk of infections and the drastically reduced life span of dyed fish. Since the dye makes the painted fishes susceptible to various health problems, they will usually die young and force you to purchase new fish.
Introducing a very sensitive fish to the aquarium is also unfair to the other inhabitants, since the weakened fish can function as a breeding ground for a colony of malicious micro organisms that eventually grows large enough to start infecting the other fish. Fish death is of course something unavoidable in the aquarium as well as in the wild, but introducing a fish that you know might die very soon is still not a very good idea. If you do not notice the dead fish it will start to decompose and seriously pollute the water. If this happens when you are away during the weekend, you might come back to a very lifeless aquarium. Always selecting healthy and strong looking fish is therefore very important even when it comes to non-painted fish.
Painted fish are often sold to less experienced fish keepers that are attracted to the vibrant colours without realising that they are unnatural. When the fish turns belly up in the aquarium, the novice aquarist thinks that it is his or her own fault and never complains to the seller. Chances are, the aquarist will even go back to the same store and purchase even more painted fish, hoping that he or she will manage to take better care of it this time.
Painted fish are also known as juiced fish, artificially coloured fish, or dyed fish. Fish can be coloured using several different methods. The three most common methods are dye injections, dipping and coloured food.
During a dye injection, a needle is used to inject dye under the skin of the fish. Just like when a human is tattooed, only a small area of skin will be dyed from each puncture. A large amount of punctures is therefore necessary before the desired coloration is achieved. This is of course very stressful for the fish, and the punctures can easily become infected. As mentioned above, the Indian Glassfish (Chanda ranga
) is one example of a fish that is commonly dyed using dye injections. A dye-injected Indian Glassfish is much more susceptible to cotton fungus than a non-dyed Indian Glassfish. In this fish, the common forms of dye will metabolize within 4 to 20 months. How long the fish will stay colourful will depend on the particular fish, which type of dye that was used and how concentrated the dye was.
Many fish species rely on an outer slime to protect them from injury and infections. During dipping, the fish is placed in a caustic solution that removes this mucus from the body. The fish is then dipped in dye, or injected using the needle method described above. When the dying process is over, the fish is dipped in yet another solution. This solution consists of chemicals that are known to irritate the skin of fishes, since the irritation will stimulate the fish to produce a new slime coating. Anyone can understand how stressful these various treatments are for the fish.
It is perfectly natural for many fish species to develop new or enhanced colors when they consume colorful food. In the wild, many fish species will happily gulp down colorful shrimps, red algae, plankton and krill. Using this naturally colorful food types to enhance the coloration of your aquarium fishes is usually not a problem. Even if krill can not be found in the native waters of your particular fish species, they may very well do great on a diet that contains krill since many fish species are opportunistic omnivores that can eat a wide range of different foods. Today you can even purchase prepared fish food that will enhance the color of fish. Many of these foods have been specially made to suit a particular fish species, and will therefore not only contain colored food particles (such as shrimps, red algae, plankton or krill) but also be balanced in order to satisfy the nutritional needs of that particular species.
So, using food to change or enhance the coloration of a fish does not necessary have to cause health problems for the fish. The problem occurs when fish producers start feeding their fish food that contains unhealthy and unnatural dye. Unsuitable dye will weaken the fish and make it less resilient towards disease. Unsuitable dye can also affect the growth and development of a fish, which is especially problematic since it is usually young fish that is fed this type of dyed food.
If you purchase a fish that has been dyed using food, you should be aware that the beautiful colors will vanish as soon as you start feeding the fish normal fish food. This is true regardless of whether the food is comprised of natural color enhancers like krill or consists of unnatural and dangerous artificial dye.
How to avoid getting dyed fish in the pet store
Many different fish species are dyed. If you do not wish to purchase dyed fish, the best way of preventing it is to research the species you are interested in before you make any purchase. Visit the library or look up the fish on the Internet. This way, you will find out if those neon green streaks are a natural part of the fish's coloration or if they must have been created using some form of dye. The word “painted” in the name of a fish that you find in the pet store is naturally also a warning. If you wish to avoid dyed fish, you should be extra suspicious when you are offered to purchase fish with names like “Painted Glassfish” or “Painted Corys”. Dyed fish are however sold under many other names as well, including the common name for the un-dyed fish.
Examples of fish that is commonly dyed
Bubblegum Parrot or Jelly Bean
Fish sold under these names are dyed versions of the Bloody Parrot fish. The Bloody Parrot does not exist in the wild; it is a human made hybrid that has been created by crossbreeding several different colorful cichlids. The Bloody Parrot cichlid is not
a red color variation of the Parrot cichlid (Hoplarchus Psittacus
). Bubblegum Parrots and Jelly Beans are dyed using bright colors like purple, green, red and blue. Their immune system is often damaged by the dyeing.
Sometimes albino versions of the Oscar fish (Astronotus ocellatus
) occur, and it is these pale fishes that are injected with blue dye and sold as Blueberry Oscars. The Oscar fish comes in several natural color variants, but brilliant blue is not one of them. The albino version can naturally be injected with other colors as well, so before you purchase a colorful Oscar it is a good idea to find out whether it has been dyed or not. By purchasing a healthy Oscar instead of a dyed one, you can get a fish that stays with you for 15 years or even longer.
Fruit tetras are White Skirt tetras that have been dyed using the dipping-method described above. The White Skirt tetra is an albino version of the Black Skirt tetra. Fruit tetras can usually be obtained in a wide range of pastel colors. Many pet stores give the fishes names after similarly colored fruits, hence the name Fruit tetras. You can for instance find Grape tetra, Blueberry tetra and Strawberry tetra. During recent years it has even been possible to obtain Holiday tetras that have been dyed to fit the upcoming holiday, e.g. red Christmas tetras and blue and red 4th of July tetras.
Dying the tail of the Cory is the most popular variant, but some fish producers dye other parts of the fish as well.
Blue Botias can be found in the wild, but fish stores have instead retorted to selling dyed blue Botias. A natural Blue Botia can also be dyed to enhance the color.
As mentioned earlier in this article, the Indian Glassfish (Chanda ranga
) is frequently dyed using brilliant colors. Since these fishes are quite colorless is their natural form, the dye will produce a sharp contrast and stand out very clearly. Fluorescent glassfish is very popular, but the artificial colors will of course gradually fade until they have vanished completely. A high percentage of the painted Indian Glassfishes die when they are being painted, or right afterwards, and those who manage to survive become highly sensitive and prone to infections.
Didn't find the info you were looking for? Register for free and ask your question in our Aquarium forum !
Our knowledgeable staff usually responds to any question within 24 hours
Invasive fish species - An introduction to the problem with introduced species and the damage the cause.