|MadSci Network: Zoology|
I believe we answered at least one other question of yours. Hope you were satisfied! Organisms that emit light would not be limited to the Animalia, so I trust I’m not digressing when I mention photo-luminescent bacteria, plants such as Dinoflagellate Algae, Fungi and of course the many “luciferous” animals!
The bacteria go back in time a long way and occupy almost every niche on earth. The marine bacteria that give a glow to the sea surface as well as most of the the bioluminescent organism we know produce a blue-green light based on very few chemicals such as luciferin and coelenterazine. This does not mean however that they can produce much ultraviolet (UV) light. The black light you mention is achieved by excluding (filtering out) non-UV light artificially by means of special glass. Living things produce many wavelengths , including even red. They don’t need to produce any invisible light such as UV whereas humans have many uses for UV such as sterilisation in food and sewage plants. This survey gives you some examples of the organisms that produce light: http://photobiology.info/Haddock.html
The spectra produced by the two substances I mentioned now remain the only interest from your point of view; 400 nm being the border where violet becomes ultra-violet (UV) light, their peak emission is around 600 nm.
The UV component of their emission being very limited, I suggest that your hopes for “blacklight” are limited, unless some new chemical is discovered. In all the phyla I noted in the first reference, very few substances were involved, apart from the two mentioned. This is where you could find, in the future, some relevant material.
The fact remains that no organism is known to sterilise or otherwise treat its environment as humans do, so it is extremely unlikely that your light will be found in nature, because there is no known function. Objects that appear ultraviolet are designed to attract animals with a UV sense (like bees). Luminescence doesn’t seem to be used with such organisms.
I suggest you look at one of the famous Japanese squid as some of the most beautiful luminescers around (see: http://www.collisiondetection.net/mt/archives/2007/02/_so_a_bunch_of.php). It seems to stun its prey with the visual effect of its display!
Try the links in the MadSci Library for more information on Zoology.