Biofluorescence gives different species of fish with brilliant colors that are invisible to man's naked eye.
According to researchers, there are more than 180 species of fish from at least 50 taxonomic families which have the ability to absorb light and emit it with a different color. The survey was conducted by sampling waters gathered from the Solomon Islands and the Bahamas. These regions were chosen since they were considered as taxonomically-rich regions. The researchers also studied water samples from Madagascar, US Great Lakes and the Amazon, where freshwater species are known to thrive.
After analysing the data taken from cameras fitted with yellow-coloured filters, the team found out that bioflourescence is a phenomenon shared by bony fish such as eels and flatfishes and cartilaginous fish like the rays and sharks. Researchers also theorize that as the depth of the waters increase, species of fish are able to absorb more amounts of light. They also noted that although there are freshwater and deep-water species of fish that are biofluorescent, they are very rare.
Most of the fish display yellow light and as seen as such by members of the same species. Bioflourescence also works as a hidden signal for the fish, researchers speculate. There are also some species whose bioflourescence are more noticeable under the light of a full moon.
"It's like they have their own little private light show going on," said John Parks, a curator of ichthyology at the American Museum of Natural History, to Nature.com. "We were surprised to find it in so many."
The study also looked into a potential supply of fluorescent proteins which can be useful for biological research. Green fluorescent protein (GFP) which was found in a species of jellyfish in the 1960s has been used for studies about brain anatomy and possible cure for AIDS.
This study was published in PLos ONE.