Painted fish are ornamental
aquarium
An aquarium (plural: ''aquariums'' or ''aquaria'') is a vivarium of any size having at least one transparent side in which aquatic plants or animals are kept and displayed. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, aq ...
fish which have been artificially coloured to appeal to consumers. This artificial colouring, also known as juicing, is achieved by a number of methods, such as
injecting the fish with a
hypodermic syringe
A syringe is a simple reciprocating pump consisting of a plunger (though in modern syringes, it is actually a piston) that fits tightly within a cylindrical tube called a barrel. The plunger can be linearly pulled and pushed along the inside ...
containing bright fluorescent colour
dye
A dye is a colored substance that chemically bonds to the substrate to which it is being applied. This distinguishes dyes from pigments which do not chemically bind to the material they color. Dye is generally applied in an aqueous solution an ...
, dipping the fish into a dye solution, or feeding the fish dyed food.
This controversial process is usually done to make the fish a brighter colour and more attractive to consumers. The colouring of the fish is not permanent, and usually fades away in six to nine months.
Methods
There are a number of methods for introducing artificial colour into fish.
Dyes
A common method of creating "painted fish" is through dye injection via syringe. Generally,
fish are injected multiple times.
Fish may also be dipped in a caustic solution to strip their outer
slime coat
The slime coat (also fish slime, mucus layer or slime layer) is the coating of mucus covering the body of all fish. An important part of fish anatomy, it serves many functions, depending on species, ranging from locomotion, care and feeding of o ...
, then dipped in dye. These methods are reported to have a very high mortality rate.
Many varieties of "colour-enhancing"
foods
Food is any substance consumed by an organism for nutritional support. Food is usually of plant, animal, or fungal origin, and contains essential nutrients, such as carbohydrates, fats, proteins, vitamins, or minerals. The substance is ingest ...
for aquarium fishes are available to the consumer. Generally, these foods contain natural dyes, such as
beta-carotene, and are not harmful to fish, although, as with other dye methods, the effect is temporary. One source reports that harmful dyes are sometimes used by wholesalers, however.
Lasers
Fish can also be tattooed using a low-intensity
laser with a dye, a process that was developed by scientists for fisheries but is now applied to ornamental fish.
Hormones
Hormone administration can sometimes increase colouration, although it can also render female fish infertile.
Genetic modification
Introduction of genes for fluorescent pigments, derived from corals and jellyfish, results in permanent colouration that is also passed on to offspring, without the need to inject or physically modify the fish themselves.
Aquarium fish genetically modified to fluoresce in bright colours under white or
ultraviolet light are now available commercially, under the trade name
GloFish. The technology was originally developed to produce a fish capable of detecting environmental
pollution. These
zebrafish and
tetras are available in several fluorescent colours, protected by a United States
patent.
Varieties
Some species, such as albino
Corydoras and "painted" glassfish, are injected with dye using a
hypodermic needle. In more recent times (2004-2005), injection dyed albino
Plecostomus and rift lake
cichlids have also become available. Other than the Indian Glassy Fish, most dyed fish are albinos.
Some commonly painted species
*
Indian Glassy Fish
''Parambassis ranga'', commonly known as the Indian glassy fish, Indian glassy perch, or Indian X-ray fish, is a species of freshwater fish in the Asiatic glassfish family Ambassidae of order Perciformes. It is native to an area of South Asia ...
(''Parambassis ranga''). Tradename: Painted glassfish; Disco Fish; Colored Glass Tetra; Lightbulb tetra.
*
Black tetra
The black tetra (''Gymnocorymbus ternetzi''), also known as the black skirt tetra, petticoat tetra, high-fin black skirt tetra, black widow tetra and blackamoor, is a freshwater fish of the characin family (Characidae). It is native to the Parag ...
(''Gymnocorymbus ternetzi''). Tradenames: Berry Tetra; Painted Tetra.
*
Oscar (''Astronautus ocellatus''). Tradenames: Blueberry Oscar; Strawberry Oscar.
*''
Corydoras'' species
*African Rift Lake
cichlid
Cichlids are fish from the family Cichlidae in the order Cichliformes. Cichlids were traditionally classed in a suborder, the Labroidei, along with the wrasses ( Labridae), in the order Perciformes, but molecular studies have contradicted this ...
s, such as ''Pseudotropheus''. Tradenames: Ice Blue Albino Cichlid; Zebra Ice Albino Cichlid.
*
Suckermouth catfish (''Hypostomus plecostomus''). Tradenames: Patriotic Suckerfish; Mixed Color Suckerfish.
*
Blood parrot cichlid
The blood parrot cichlid (''Amphilophus citrinellus'' × ''Vieja melanurus''), or parrot
cichlid, is a hybrid species of fish in your the family Cichlidae. The fish was first bred in Taiwan around 1986. Blood parrots should not be confused wit ...
(''Amphiliphus citrinellus'' x ''Heros severus''). Tradenames: Jellybean Cichlid; Cotton Candy Cichlid.
*
Goldfish (''Carassius auratus''). Tradenames: Jellybeans; Icepops.
Health hazards to painted fish
A 1998 survey carried out in the South of England revealed that over 40% of painted
glassfish showed signs of a ''
Lymphocystis'' infection, compared to 10% of unpainted glassfish. The infection may have been caused by transmitting the virus from fish to fish via an infected needle, or by a reduced resistance to the infection due to stress from the injection process.
In addition, fishes injected with dye often die without apparent external disease symptoms, presumably due to kidney disease caused by injection.
Efforts to stop fish-painting
Some members of the aquarium trade want to ban this practice. For example, the British publication ''
Practical Fishkeeping'' started a campaign in 1996 to ask retailers to stop selling dyed fish, which led to a significant decrease in the number sold in the
United Kingdom. ''Practical Fishkeeping'' has launched a similar campaign with a global scope and maintains a register of stores which do not stock dyed fish. The
Royal Society for the Prevention of Cruelty to Animals (RSPCA) regards the practice as cruel and unnecessary cosmetic
mutilation. A campaign in Australia and in the UK has limited the sale of these fish. Dyed fish are still available and are generally imported from
Southeast Asia.
In February 2006, the UK's
Department for Environment, Food and Rural Affairs
The Department for Environment, Food and Rural Affairs (Defra) is a department of His Majesty's Government responsible for environmental protection, food production and standards, agriculture, fisheries and rural communities in the United K ...
(Defra) confirmed that it would not be making it illegal to sell dyed fish in the UK under the Animal Welfare Bill.
References
Related Sites
Painfully Painted Fish{{Aquarium
Fishkeeping
Animal welfare