Swordtail fish of the red velvet variety
were obtained from grazed down (clear water)
ponds. They were treated with the feed described
above ± 1.5% Spirulina and 1% Haematococcus.
Rainbowfish were obtained from clear water,
indoor aquaria and treated with the feed containing
2% Spirulina and 1% Haematococcus. Control
fish of each species were fed a flake feed which
reported no source of carotenoids in the listed
ingredients. Topaz cichlids were obtained as
juveniles and were reared in the same way as the
rainbowfish. Treated cichlids were fed as
described above but control fish animals were fed
a commercial cichlid feed containing alfalfa meal
as the carotenoid source. Among the cichlids, no
color changes were observed after 3 wk and the
experiment was continued for an additional 3 wk
after bottles were put into the tanks to provide
territories.