An exotic Asian fish fed exclusively on Kit Kat chocolate wafers his entire life has been put on a fruit-based diet by his new owners at London's Sea Life Aquarium.
"Gary" the giant gourami, a species of freshwater fish native to parts of South East Asia where it is farmed for food, is 40 cm long (16 inches) and tips the scales at 4 kg (9 lb).
The fish's refusal to eat mystified staff at the aquarium until they discovered that its previous owners fed it entirely on Kit Kats, the chocolate confection made by Swiss-based global food company Nestle.
"I have never heard of a fish being fed chocolate, let alone being brought up entirely on the stuff", Rebecca Carter, Gary's handler said in a statement on Sea Life's website.
"Gouramis usually eat a diet of fruit but Gary doesn't appear to have suffered any ill effects from his chocolate addiction. However, we would not recommend feeding fish confectionery of any kind!"
Aquarists had to stuff crumbled Kit Kat pieces into grapes and pieces of banana to wean the fish off chocolate and onto a more conventional diet.
Gary is just one of a number of fish that have been taken in by the aquarium after their owners were no longer able to care for them.
Staff have even been dubbed one display the "tankbusters", as it houses several fish that grew too large for their owners.
"Many people don't do the right research when they buy fish and end up unable to care for them," said Carter.
"Catfish are a good example and we have a number here that outgrew their homes. We'd urge people to think before they buy. We're delighted we could find a home for Gary but the fact is we simply do not have the space to accommodate the vast number of re-homing requests we receive."