Recently, I’ve been asked this question on numerous occasions,”How much food do I feed my fish?”
Thinking back on several necropsies I had done, I’ve found goldfish, koi, and aquaponically grown fish to be rather high in abdominal fat content (similar to those adverts by the government about ‘toxic fat’. Bit why is this the case?
Goldfish and koi are a bit of a guts when it comes to food. And many owners are too nice to their fish…and feed them too much… Inadvertently, killing them with kindness.
Fish on average, eat about 1% of their body weight daily. Mature fish that are no longer growing will eat 0.5%, and young rapidly growing fish will eat as much as 2%. Does this vary depending on the seasons? Yes it does, and see a previous post (https://thefishvet.com/2011/06/23/how-often-should-i-feed-my-fishes/)
Aquaponically grown fish tend to be on a diet that enables them to grow at an accelerated rate and such foods tend to contain a lot of fat and protein. And this explains why they are so fatty.
The excess fat is stored by the fish in its abdomen. It occupies space in a cavity that’s rather rigid and non-distendable. There is no health implications for the fish cultured for food since they will be harvested relatively young, but what impact will it have for the pet fish who are to live for years?’