Green Fluorescent Protein (GFP) has existed for more than one hundred and sixty million years in one species of jellyfish, Aequorea victoria. The protein is found in the photoorgans of Aequorea, see picture below right. GFP is not responsible for the glow often seen in pictures of jellyfish – that “fluorescence” is actually due to the reflection of the flash used to photograph the jellies.
(Photocredit: Steve Haddock and his bioluminescence web page,
Monterey Bay Aquarium Research Institute)