Why are goldfish bowls a cruel practice?
It is common to hear people say that goldfish are relatively hardy. It is true that slim-bodied goldfish (common goldfish, comet, etc) are hardy fish, while fancy goldfish are more delicate.However, an unfiltered bowl or ‘mini-aquarium’ is not suitable for any type of goldfish.
Goldfish grow relatively quickly and produce a lot of organic waste: this is why the goldfish bowl / mini-aquarium will only allow them to live for a very short time and in bad conditions because:
- Oxygen quickly becomes scarce in such a small volume: the fish slowly suffocate
- The temperature differences are brutal, which stress fish and encourage the development of diseases
- Fish are poisoned with their own waste (ammonia in particular, the substance that you smell in urine, which burns the fish’s gills)
- Goldfish’s growth in a bowl or mini-aquarium may be stunted
Goldfish maintained in fish bowls usually have a reduced life expectancy
Picture: anothersarah under creative Commons BY-NC-ND licence
For good living conditions
The pet store I usually go to is an example of a good store: before one buys any fish, they first ask: which other fish do you want to put them with? (to identify potential interspecies incompatibility). Then, ‘when was your aquarium first started?’ (to find out if one has a properly functioning filtered tank). Finally, ‘how big is your tank?’
PET STORES, SUPERMARKETS OR FAIR ORGANIZERS: ASSUME YOUR RESPONSIBILITIES! REFUSE TO SELL GOLDFISH BOWLS OR TINY AQUARIUMS. ALSO REFUSE TO SELL GOLDFISH IN UNFILTERED TANKS!

To answer this question, here is a short excerpt from an article found on the BBC News website, entitled “Fish do feel pain, scientists say”. The first conclusive evidence of pain perception in fish is said to have been found by UK scientists. Fish have pain receptors like us. This complements earlier findings that both birds and mammals can feel pain, and challenges assertions that fish are impervious to it. Scientists found sites in the heads of rainbow trout that responded to damaging stimuli.They also found the fish showed marked reactions when exposed to harmful substances.” By Alex Kirby – 30/04/2003
Full article here: http://news.bbc.co.uk/1/hi/sci/tech/2983045.stm
Important: the comments area below is not for urgent queries about fish health but for general feedback, comments and questions, as we normally check comments twice a week. Therefore, it you have a question about a sick fish, it is advisable to first check the health and disease section. If you do not find the answer to your questions there, please post your question in a fishkeeping forum, which usually allows to get help in a timely manner, or contact your local vet.