If you're a beginner, visiting an aquarium shop can be like a trip to Willie Wonka's chocolate factory; everywhere you look there are fish of every shape and colour and some of these are unbelievably bright, with all manner of fluorescent hues. Oddly, in a hobby that's not without controversy and misconception over all manner of things, these are the result of artificial pigments. Many things have changed in the last few decades of the aquarium industry but sadly one thing has not: there are still people who take advantage of the fact that customers want the brightest fish in the shop and won't always know the nature of these specimens.
Typically, dyed fish receive their unnatural colours in a couple of ways - either through injection or immersion. Generations of fish keepers have seen colour injected Glass fish, where one or two fluorescent pigments are injected into the flesh of these transparent fishes and a shared needle means that viral infections such as Lymphocystis are rife in such batches. Given time and good care, these specimens can survive this abuse and fade back to a more natural shade but it is extremely stressful and debilitating. With an increasingly large range of albino versions of cheap, hardy tropicals to choose from, more of them started to fall under the needle and tetras, Corydoras catfish, gouramis and even cichlids started to appear. The rise of the 'bloody parrot' saw the start of tattooed fishes appearing and stripes, spots and even simple messages were seen.
Immersion in dye is a less invasive technique but is still massively stressful for the unlucky fish or even amphibians facing the ordeal. The poor old parrot fish once again falls prey to this treatment more often than most, as do more surprising victims such as Axolotls and Albino Clawed Frogs. With a lower risk of secondary infection, animals are more likely to survive and fade but it's still a terrible way to treat a sensitive, live creature. As the process involves harsh chemicals, it remains damaging and compromises the animal's welfare.
Maidenhead Aquatics decided decades ago that this practice went against what we believe is the very core of our ethos - putting the welfare of our livestock firmly at the top of our priorities. We've informed our suppliers that we don't want these fishes in our stores and we actively encourage hobbyists to vote with their wallets and shun any shop that sells them. Like some of the "Tankbusters" we go out of our way to avoid, we do still see the occasional specimen arrive as a rescue or accidental delivery, but we try to handle these as sensitively and responsibly as we can, in most cases using them as a cautionary example to staff and customers alike.
Of course, it's no use avoiding a shop without telling them why and there are actually a couple of naturally bright fish that really do look as though they've been artificially coloured. If you have any doubts or concerns, speak to the staff on the shop floor. At first glance, both Redline torpedo barbs (Sahyadria denisonii) and Laser Corydoras have the sort of well-defined vivid colouration that looks like it was put there using a needle. All the more surprising then, that people would seek to make artificially colourful fish when nature has already given us thousands to choose from. Remember - if people stop buying them and they're seen as bad for business, importations should cease and thousands of fishes will benefit.