It's a gray fiberglass insulated aquaculture tank. I did have the overhead light on while netting them.
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=359690&page=14The yellow of females blanches as season progresses unless on diet loaded with carotenoids.
When we breed sunfish such as RES indoors, the feed is often supplemented with paprika. Purpose is to increase coloration of eggs. Clear-ish eggs do not appear to hatch as well. The females store the carotenoids as pigment in the skin. The pigment is mobilized each time the female matures a batch of eggs. Females pushed hard to produce multiple clutches in rapid succession get a silvery look.
Snails and the like may not be good sources of carotenoids. Crustaceans like in the plankton, which BG more inclined to eat, are better.
