red pigment in zebrafish

Sat Apr 2 01:49:00 EST 2005



The diet (a custom Silver Cup formulation with high pigment levels and
spirulina) we are using  gives a good yellow/orange color to the fins and
sometimes the body of the males of our strains.  The gold variations will
show red strips on a gold background.  The older fish appear to show
better color and I have no idea why.

Using our diet without pigments, we don't see any color and even the gold
variations appear white.  Some years ago, we did a study which tested the
same diet with and without the pigments and for zebra fish we obtained
better results with pigments and guppies did better without the pigments
-- the effects weren't very large, but good enough to make a business
decision (you don't need 95% confidence levels to make a rational decision
on what feed to use).

I have seen bacterial infections on some fish which will give a red color
to the fins -- but that is not good.  This is more common around the base
of the fin and can be a very blood red color.


Dallas E. Weaver, Ph.D.
Scientific Hatcheries
5542 Engineer Dr.
Huntington Beach, Ca 92649
deweaver at

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