New research decodes the secret language of the sea

Jul 09, 2009

(PhysOrg.com) -- Even parasite-eating fish recognise the benefits of good advertising, UQ research has found.

UQ’s Dr Karen Cheney and Professor Justin Marshall, along with colleagues from the School of , found cleaner - which are in the business of removing parasites from larger reef fish - used colour to catch the attention of potential clients.

Published online in scientific journal is a study showing how cleaner fish have evolved a specific advertising signal involving a blue and yellow colouration, combined with conspicuous stripes.

“A combination of color and pattern is an important component of cleaner signals and helps attract client species to cleaning stations," Professor Marshall said.

Cleaner fish operate out of cleaning stations, usually found among the rocks and seagrass of the reef.

By using visual models, the researchers were able to “look through the eyes of potential clients”.

“We were actually able to see what message the cleaner fish is sending from the perspective of the client,” Professor Marshall said.

“We measured the visual response of three coral reef fish: the barracuda; the UV-sensitive planktivorous damselfish; and the herbivorous surgeonfish.

“For all three visual systems, blue categories were the most contrasting colors against an average coral background, and yellow is the most contrasting colour against a blue water background.

“Therefore, blue and yellow appears to be the most conspicuous colours when signaling to potential clients.”

Using behavioural trials, the researchers also showed reef fish were more likely to visit cleaners whose bodies contained blue patterns.

“We tested the response of wild client fish to seven fish models made from resin and painted with a range of colors and patterns,” Professor Marshall said.

Reef fish - which ordinarily would eat the smaller cleaner fish - swim up and pose in a way which indicates they are ready for cleaning.

“The reef fish needs to be cleaned and the cleaner fish needs to eat the parasites in order to survive so there's a mutually beneficial relationship that exists between the cleaner and the host,” Professor Marshall said.

“A cleaner fish could be cleaning the teeth of a large coral trout and somehow it knows not to close its mouth.

“What we think the cleaner fish are saying - with colour - is that they have a service to offer.

“What we’ve managed to do is decode the language of the club.”

Professor Marshall and Dr Cheney are also co-authors of a paper featured on the cover of the latest edition of The Journal of Experimental Biology.

The study found Elacatinus gobies, a species of cleaner fish found in the Caribbean, had developed blue and yellow stripes so they stood out to passing reef fish.

"Yellow and blue are the two colours which transmit best in the ocean," Professor Marshall said.

"It's interesting that these fish have managed to pick the right physics in terms of the colours that transmit the longest distance."

Provided by University of Queensland (news : web)

Explore further: Warning coloration paved the way for louder, more complex calls in certain species of poisonous frogs

add to favorites email to friend print save as pdf

Related Stories

Fish behaviour of the highest order

Jun 22, 2006

New research, which has been published in Nature, has uncovered evidence of fish behaviour more commonly associated with humans.

Major losses for Caribbean reef fish in last 15 years

Mar 19, 2009

By combining data from 48 studies of coral reefs from around the Caribbean, researchers have found that fish densities that have been stable for decades have given way to significant declines since 1995. The study appears ...

Colour pattern spurs speciation in tropical fish

May 28, 2007

McGill researchers discover that coral reef fish colour patterns are responsible for the emergence of new species A team of researchers from McGill University and the Smithsonian Tropical Research Institute (STRI) has provid ...

Fantastic photographs of fluorescent fish

Sep 16, 2008

Scientists have discovered that certain fish are capable of glowing red. Research published today in BMC Ecology includes striking images of fish fluorescing vivid red light.

Longest study finds reef fish need longer break

Jul 11, 2007

In the longest running study on how fish populations in coral reef systems recover from heavy exploitation, researchers from the Wildlife Conservation Society (WCS) and others have found that the fish can ...

Recommended for you

Cat dentals fill you with dread?

15 hours ago

A survey published this year found that over 50% of final year veterinary students in the UK do not feel confident either in discussing orodental problems with clients or in performing a detailed examination of the oral cavity ...

User comments : 0