Fluorescent proteins have been employed in a variety of scientific research purposes but, until now, such natural proteins have been identified mostly in jellyfish and corals, leading to the belief that the capacity for fluorescence in animals is exclusive to such primitive creatures.

But in the new research, scientists at the Scripps Institution of Oceanography at the University of California-San Diego discovered fluorescent-light emitting features in an evolutionarily important marine organism -- the amphioxus -- and say such a capacity might be much more prevalent in nature than previously believed.

Dimitri Deheyn and his Scripps colleagues said their discovery emphasizes the idea that evolutionary preservation of fluorescence must play an important ecological function. Deheyn said many animals haven't been tested for fluorescence and its prevalence in the animal kingdom remains undetermined.

The research appears in the October issue of the journal Biological Bulletin.