6 replies to this topic

[centrarchid]

Anyone rearing fish in bare-bottomed tanks, especially sunfish, and tracking weights and how much they are being fed. We are seeing some very low amounts of feed required to drive a given amount of growth in bluegill. Values are well below those expected for other species of similar size. For a lb of growth we only need anywhere from 0.6 to 0.8 lb of feed. Normally ideal is around 1.0 lb feed.

[bbrown]

That's incredible.
Am I understanding you correctly that you are seeing a pound of gain per .6 to .8 pound of food fed, and that there is no other food source? I think most consider anything better than 2:1 feed conversion to be pretty good.
Not sure how you could get more out than you put in.

[Michael Wolfe]

I'm glad someone else said it. As an engineer by training I was wondering about the whole conservation of mass issue. How are these fish metabolizing themselves into more mass than they take in? Seems impossible. Unless there is unaccounted for cannibalism involved.

[gerald]

Food is dry. Fish are wet. Hmph .... engineers.

[Michael Wolfe]

Really? That sounds like a biology answer. So only feed the fish water and you could get the 0.3 pound growth that is the difference?

[centrarchid]

Yes Gerald, dry feed to wet fish. Our fish are about %70 wet. In pond setting we get a feed conversion of 1 to 1.2 lb per pound growth. Most trials indoors we get conversions closer to 1. This recent change has involved three different experiments where key change has been how feed is applied and the diets being more nutrient dense. I do not think we could repeat it with most other sunfish with possible exception of redear. Something interesting may be at play with respect to effeciency of movement. Idea started to develop when watching fry of various sunfishes feeding in a tank. Pectoral fin shape of particular interest.

[gitano]

"Dry food" - Now that's funny!

Paul