Re: [RML] Rainbows and Diet

Bruce Hansen (bhansen at
Fri, 8 Aug 1997 09:09:35 +1000

I think that an opportunistic carnivore like a rainbowfish is going to get
a large variety of sources of foods - simply by the nature of seasonal and
locality production of these insects(terrestrials falling in, aerials
falling in and aquatic larvae), crustacea(various adults and larvae), small
and larval fish (including their own fry), worms of various types as well
as plant material, pollen, small fruits and other odds and sods.

I agree that especially in soft waters that insect exoskeletons may supply
some nutrition but I feel that most skeletal deformities in our aquarium
stock are due to lack of calcium in their food and water as well as
insufficient Vitamins C and D.

Your point about too much insects is well taken.I agree that the imsects
probably act in fish somewhat like fibre does in us. Remember that we now
have good evidence that too much meaty and fatty food (e.g. beef heart) can
lead to problems, so it just tends to support the old contention that
variety is the spice of life.

bhansen at

> From: rhondawi at
> To: rainbowfish at
> Subject: [RML] Rainbows and Diet
> Date: Friday, 8 August 1997 4:23
> I was noticing, a while back, that when I feed a lot of mosquito larva to

> fish they often seem to come out after being eaten about the same looking
> they went in. I figured the exoskeletons on insects are probably not very

> digestable. But that got me to thinking that insects do have exoskeletons

> and that a fish that was used to eating lots of insects would be set up
> deal with this in some way, or maybe even use them in some way. I don't
> really know if what I'm saying has any relevance at all. However it seems

> that it may be worth looking at.
> It seems that the fish may utilize this part of their diet in some way
> it's something that they really wouldn't get in an aquarium, even if they

> are getting the other nutrients that may be found in an insect. Could
> be getting something out of the exoskeleton, perhaps this is why there
> often troubles with crooked fish and lack of fin developement that
> many to add calcium type blocks. I also was wondering if somehow they
> aid in digestion, kind of like fiber for people.