The iPond, which is designed to resemble Apple Corp's best-selling iPod music player, is up to 15 times smaller than the minimum recommended tank size.Melbourne-based chain store Pets Paradise is selling the $70 product at outlets across the city and it is proving such a hit that one city store has sold out and a suburban shop is down to its last two.
The RSPCA wants the iPond banned because it is too small to give fish adequate oxygen supplies, swimming room and a clean environment.
Melbourne Aquarium head curator Nick Kirby says the minimum tank size for a Siamese fighting fish, which Pets Paradise sells with the iPond, is 10 litres. The iPond tank - which is manufactured in the United States and is not associated with Apple - is just 850 millilitres.
The iPond allows owners to plug their MP3 player into it so music plays through a speaker built into the bottom of the small brick-shaped tank.
However, once small stones are placed in the bottom of the tank - which Pets Paradise staff recommend to "block the noise" for the fish's comfort - its water capacity shrinks to an intolerable 650 millilitres.
In the wild, Siamese fighting fish - which are native to Thailand and known as "the jewel of the Orient" for their spectacular colours - can be found in confined bodies of water such as large puddles, but they are far bigger than 650 millilitres.