*Warning Lots of Science Ahead*
The jellyfish that GFP (green fluorescent protein) is found in actually lives off the coast of BC. This type of Molecular Genetics is useful for a lot of developmental biology - I do the same things with bacterial cells and lactose operon/plasmid DNA transformants (the cells are the transformants, that is).
You could attach the GFP gene next to the native gene that you want to know when it is expressed in vivo, and when the promoter for the native gene reads through the GFP gene it will also produce GFP.
This is the link, and it states that the GFP excites at a light wavelength of 365nm which falls in the UV-A range. Typical reptile UV bulbs also emit UV-B (~290-320nm) which is higher energy than UV-A. Of course because GFP fluoresces green, it emits photons in the 520-560nm range, which our eyes perceive as green.
Sorry to bore you all..
Rob