For those who aren't on gaia, we have the ability to own our own aquariums and fish. "Booty Grab" is the game associated with the aquariums, and you basically go around and catch the gold that the fish are dropping.
Currently, it is "Big Booty Week" which the staff of the site has deemed, and the gold that glows green is like double the amount of regular gold.
As you can imagine, I was quite happy when three fish decided to grant me lots of green gold ;D