Artificially coloured fish have been available for a number of years - appearing first around 1980 (McMahon & Burgess 1998). The first fishes to be coloured were painted glassfish their transparent bodies providing a blank canvas for the dyers. More recently at least in Australia, albino corydoras that have been dyed blue, red, yellow or green have appeared in a number of stores.

In 1998 MacMahon and Burgess investigated how the dye was applied to the fish. A number of rumours circulate in hobby as to the exact method of application - not surprisingly this dubious practice is not well detailed, some maintain the dye is applied to the outside of the fish, while others speak of injection via hypodermic needle. To determine exactly how the dye was applied MacMahon and Burgess sedated several glassfish and examined them under a microscope. It was obvious to the authors that the dye was not outside the epidermis (the outer layer of cells), but under it. The authors comment that the dye remained fluid under the “skin” of the fish. The only way for this to have occured would be for dye to have been injected into the fish at a large number of points.

The authors go on to say that after viewing photographic evidence of this practice which is undertaken by fish farmers in Asia, the bore size of the needle is relatively large. Even if one considers a very small needle, the relative size of the needle to the small size of the fishes being injected - means that it would be similar to us receiving multiple injections with a pencil sized needle.

Burgess and MacMahon also carried out a survey of rates of infection of lymphocystis, a virus that causes small white growths on the body, in both painted and unpainted varieties of painted glassfish. They found an increase of almost 30% infection in painted varieties when compared with their undyed equivalents. They speculated that this increase in disease is presumably from transmission of the virus via unsterile needles. They also state that it may be due to decreased immune system function due to the stress of the injection process. There is also strong evidence in histological material of severe kidney trauma associated with the relatively large amounts of dye being injected. (Phillips, B. pers. comm.)

In time the dye fades, and the fish takes on normal coloration. Albino versions of Corydoras catfish, Tiger Barbs, Labeo “sharks”, Black widow Tetras, Albino loaches, blue oscars and ram cichlids have also provided a clean canvas for dying.

This is a cruel, unethical and immoral practice, which, given the range of beautiful tropical fish available in the fishkeeping hobby is completely unnecessary.

What do other people think of this practice?

The Australian RSPA said:

…We have investigated the practice of dyeing fish through injection and have resolved that the procedure is unnecessary and has the potential to compromise the health and welfare of the fish. These effects may include the introduction of disease and the handling of the fish can compromise the protective antibacterial mucus layer on the surface of the fish. Although the RSPCA has no specific policy on this practice, it would be considered similar to the practice of surgical mutilation such as the tail docking of dogs: ‘RSPCA Australia is opposed to the mutilation of animals for cosmetic (non-veterinary purposes).’ This practice is certainly purely for cosmetic purposes only, is not necessary and can be potentially damaging to the fish. The RSPCA therefore would oppose this practice…Obviously what is required is a cultural change in the industry and the education of buyers that fish should not be dyed as there can be negative health effects on the fish…

What can I do?

Consumers/Hobbyists: If you see painted glassfish in an aquarium tell the owner or manager that this is a cruel practice. If enough people complain we can stop the sale of these fishes. The sad truth about dyed fish is that most often they are bought by people who are new to the hobby and would not suspect this practice. When new aquarists discover the truth about this practice they are normally saddened that they have been deceived into buying fish that are coloured for profit.
Aquarium Owners/Wholesalers: Contact me to be added to our list of juicing free aquariums.

Webmasters: Link to this article, spread the word.

Australian Retailers & wholesalers who have pledged NOT to stock dyed fish

I would like to thank all the aquariums and wholesalers listed below (in no particular order) who support the campaign to stamp out this practice. I actively endorse ALL of the following businesses and can RECOMMEND them to the new and advanced aquarist alike:

Boronia Aquarium (VIC)

Fish4U
(NSW)

Campelltown Pet & Aquarium Centre (NSW)

Marinelife Aquarium (NSW)

Profishionals Aquarium Group

Aqua Pets Aquarium (NSW)

Pets World (NSW)

Bay Fish (QLD)

Aquarium Industries (AI) (VIC)

Auburn Aquariums (NSW)

Aggies Aquariums (SA)

House of Fish (ACT)

The Pet Shop Around The Corner (QLD)

Gold Coast Aquariums (QLD)

St. George Aquariums (NSW)

Age of Aquariums (QLD)

Xtreme Aquariums (NSW)

Aquatic Life Aquariums (NSW)

Aquatic Wholesalers (NSW)

Wings & Fins Aquarium (NSW)

References:

MacMahon, S. and Burgess, P. (1998) Why it’s cruel to dye. Practical Fishkeeping. March 1998. pg: 114-115.

Acknowledgments:

Thanks to Roger Morrison for sending me the journal article on which much of the data provided is founded. Also I’d like to thank Dr. Bill Phillips for some information regarding kidney problems in dyed fish

Whats the deal with fish that glow in the dark? I was at walmart and they had fish that would glow in the dark.

you know, I've been wondering that myself Mike! Since I read Pauls post about being dyed, it really makes me wonder if they have been injected w/something, & it's very sad that ppl do this to them! Poor little things

I know my neon tetras do to a point but that's kind of an illusion. After you turn the lights off & it's been dark for quite awhile, get a flashlight or just turn the light on & quickly look at them. They don't actually have any stripes & they glow until they adjust to lights on. I guess that's part of their survival in the wild...? They do look rather weird

These fish are no better in my opinion. They are genetically engineered fish.

http://www.organicconsumers.org/ge/glofish112503.cfm

I guess these mutants have finally surfaced.

Now that is just plain crazyness! So they say ... a zebra fish containing a gene from a sea coral? How did it get the gene? It's not like the fish mated w/the sea coral! Also, isn't it bad to have a FW species & a SW species in opposite waters, a FW fish in SW or SW coral in FW?
Wonder how the "Scientists" or "Mr. Blake" would feel if they were injected or genetically engineered/altered?
I'd SLAP THE CRAP OUTTA THESE PPL but CRAP SPLATTERS!!! :angspmd:

It just makes me sick. I've known about the dyed and injected fish but this is revolting.

Dye injected fish are seriously nasty. Even more fun when people decide to abandon them after the color fades. I ended up with a few Parrotfish like that. They were purple and blue originally but were kinda nasty colored when I got them. Normal Parrotfish are indestructible, but these were weak and feeble.

As for the glow in the dark fish, they actually don't bother me. They were created under clean sterile conditions, and while are freaky colors aren't prone to the infections and disease that the injected dyed fish are. I don't really think that it's necessary with all the colors of fish out there, but it's a much more humane way of having oddly colored fish.

I know this is old but has anyone ever actually seen these fish? do they actually glow? Canada has banned them so I will personally never know. From the story I heard these fish weren't genetically altered but exposed to some sort of radiation. I don't know of any coral that glows in the dark do you? Here we have Canadian version of the glofish which is actually a dye injected zebra danio, I'd never buy one same way i wouldn't buy a dye injected tetra. I was just curious thats all

What they're calling Glofish down here were originally developed for water testing and some other lab uses. There are axolotls the same way.

Some lab spliced genes with some sort of jellyfish, to make them glow like that. Otherwise, they're no different from normal zebras. They'll breed and pass on the florescent gene and everything.

People thought they were neat, and they started getting sold. Personally, just like the rest of the hybrids, so long as people who have them take care of them, and they're not being made out as something they're not, I don't mind 'em.

Brisch wrote:

I know this is old but has anyone ever actually seen these fish? do they actually glow? Canada has banned them so I will personally never know. From the story I heard these fish weren't genetically altered but exposed to some sort of radiation. I don't know of any coral that glows in the dark do you? Here we have Canadian version of the glofish which is actually a dye injected zebra danio, I'd never buy one same way i wouldn't buy a dye injected tetra. I was just curious thats all

The dyed fish that I've seen don't actually glow.

The glofish offered for sale in the Wyoming-Colorado region are zebra danios (Danio rerio) in which early generations were genetically altered to "glow", and the mutation breeds true. There is nothing dyed about them. They do glow somewhat under black light, but personally I find the wild type more attractive. Personally, I find the process of injecting fish with dye to be more vile than genetically altering one generation of a species so that the mutation breeds true. Outta curiosity, why has Canada banned glofish?

WYite

Australia, Canada, and Europe (I don't think in the UK though) ban the sale of any genetically modified organisms to the public unless the originating company puts up a large amount of cash for what seems like an extremely lengthy and complex review process, that odds are wouldn't even be approved.

Glofish were already in Canada though as it is. They were imported in 2004, started selling like hotcakes, and THEN got busted by some Canadian environmental body. I'm not sure if there are still any alive, but I'm sure there's a good handful of people that are breeding them up there just because they're not allowed.