An international research study has found evidence that shrimp may positively glow at the thought of sex.
The study published today in Science has demonstrated that mantis shrimps use fluoro colours to attract the opposite sex and communicate with other shrimp.
A research team from Australia and the U.S.A. discovered that mantis shrimps, which are found in most oceans of the world, have fluorescent markings.
Study co-author Dr Justin Marshall of The University of Queensland`s Vision, Touch and Hearing Research Centre said it had been known for a long time that fluorescence produced striking colour effects in corals, sponges and other marine organisms, but that these enhanced colours were nothing to do with vision or communication.
"Some organisms such as squid have fluorescent patches on their bodies," Dr Marshall said.
"However, the use of fluorescent colours as signals has never been demonstrated in the sea.
"Our study found fluorescent colouration was used in postural signalling. This contributed to the shrimp`s signal brightness, visibility and colour, particularly at greater, bluer depths where the glowing colours are very conspicuous.
"Rather conveniently, the blue light of the ocean is used by special fluorescent pigments to produce this signal and oranges and yellows are the glowing result. These colours that are `rare` at depth and may be particularly attractive."
Dr Marshall said the principal aim of his research was to understand how other animals perceived their environment.
"As arrogant humans we tend to assume we are the pinnacle of evolution, however, certainly in sensory terms this is far from true. By taking an approach to sensory systems that is based around ecology but also includes physiology, anatomy, behaviour and neural integration, we hope to decode signals and their intention in the animal kingdom," he said.
"One of the animal groups we work on is the stomatopods (mantis shrimps), reef-dwelling crustaceans with the world`s most complex colour vision system. These lowly crustaceans possess four times as many colour receptors as humans, four of which sample the UV, a region of the spectrum to which we are blind."
Last year Dr Marshall was among British and Australian scientists who found that budgerigars showed a significant sexual preference for mates with fluorescent plumage. This was the first demonstrated use of fluorescence for communication in the animal kingdom, apart from humans.
"As with the budgies, parallels can be drawn between the shrimp and with humans who use fluorescence to draw attention to things," Dr Marshall said.
"For some time humans have used fluorescence as an attractant. We have fluorescent highlighters and post-it notes, washing powders which give white fluorescence to our clothes, some advertisers use fluorescent paints in their displays and there are now even fluorescent tattoos used in night clubs."
In 1992 Dr Marshall won the L`Oreal Art & Science of Colour Prize of 30,000 Euros (~A$ 50,000) in Paris for his research on colour vision and colour communication in reef fish.
Co-authors of the new Science paper are Dr Charles Mazel of Physical Sciences Incorporated, Massachusetts; Dr Thomas Cronin of the University of Maryland; and Dr Roy Caldwell, of the University of California at Berkeley.
Media: For more information contact Dr Justin Marshall mobile 0423 024162 (07 3365 4071(w) email: justin.marshall@.uq.edu.au) or Andrew Dunne at UQ Communications (3365 2802). Images of Dr Marshall and the mantis shrimps are available by contacting Diana Lilley at UQ Communications, telephone 07 3365 2753 or email: d.lilley@uq.edu.au
