The colour of rainbows is subjected to many external factors such as
habitat, water conditions, lighting , diet and a host of other things. For
example, if you are raising them in a small bare bones tank then I don't
think you can expected much colour. Also if the diet is a static one then
the same can often be expected. On the other hand if you have them in a
30-40 gal aquarium, nicely planted, semi shaded lighting and feeding them
live mossie larvae or daphnia, then I would guess they would be sparkling on
all fins.
I just recently raised around a 120 G.incisus that I was keeping in a 30 Gal
(Aussie gals) tank and they all looked rather plain. However, when I moved
them to a 6'x2'x15" high tank, without any overhead lighting and rather bare
as decoration goes they shone like diamonds. This tank was near an easterly
facing window and when the morning light shone through the water these fish
were the colour of a beautiful sunset, rustic red all over. So you see many
things affect their colour and you just have to learn what benefits your
particular fishes. Just as a side note, this tank has a trickle filter in
operation and the flow from the filter return is fairly swift. I can tell
you - It was a delight to watch these fishes, all facing into the current,
swimming in the same position and with the morning sun shining into the
water - its no wonder I keep rainbowfishes!
However, to answer your question - I've had boesemani males colour-up at
around 1 inch. Maybe they just need a little more time or a change in
conditions.
Adrian.
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Adrian R. Tappin
Home of the Rainbowfish
http://www.ecn.net.au/~atappin/home.htm
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