Featured Research

from universities, journals, and other organizations

Glowing red in the big blue: Red fluorescence at great depths

Date:
July 15, 2014
Source:
Universitaet Tübingen
Summary:
Many fish species glow red and can see red light, even at depths where the red part of the sunlight spectrum has been absorbed by the water above. It was long assumed that red light did not play a role at depths of 10m or more. However, researchers have not only discovered and investigated the phenomenon of red fluorescence; they have now described a new detail which offers important clues to the function of glowing red.

Many fish species glow red and can see red light, even at depths where the red part of the sunlight spectrum has been absorbed by the water above. It was long assumed that red light did not play a role at depths of 10m or more. At Tübingen University's Institute of Evolution and Ecology, Professor Nico Michiels has not only discovered and investigated the phenomenon of red fluorescence; he and his team have now described a new detail which offers important clues to the function of glowing red.

The researchers examined eight different fluorescing fish species from locations as diverse as Sulawesi in Indonesia, Corsica, and the Red Sea. The comparison of individuals within a species caught at different depths (5m and 20m) at a single location yielded an unexpected result -- much stronger fluorescence at greater depths in six out of eight species.

The researchers tested the popular hypothesis that fluorescing protects the fish from ultraviolet rays -- as it does for corals which grow close to the surface and are exposed to strong sunlight. "We cannot completely exclude this function in fish, but it seems unlikely that UV protection has played much of a role in the evolution of red fluorescence," says Nico Michiels. UV radiation is much greater in shallow water, and if protection from the ultraviolet was important, the researchers would have expected fish living closer to the surface to emit greater red fluorescence -- the opposite of what they found.

This suggests a different theory -- that the fish illuminate their surroundings with red light to strengthen contrasts and see better. The researchers will now investigate exactly how the fish use the light. "If it is the eyes which produce the fluorescence, it could be used to discover hidden prey," says Michiels.


Story Source:

The above story is based on materials provided by Universitaet Tübingen. Note: Materials may be edited for content and length.


Journal Reference:

  1. Melissa G. Meadows, Nils Anthes, Sandra Dangelmayer, Magdy A. Alwany, Tobias Gerlach, Gregor Schulte, Dennis Sprenger, Jennifer Theobald and Nico K. Michiels. Red fluorescence increases with depth in reef fishes, supporting a visual function, not UV protection. Proceedings of the Royal Society B, July 2014 DOI: 10.1098/rspb.2014.1211

Cite This Page:

Universitaet Tübingen. "Glowing red in the big blue: Red fluorescence at great depths." ScienceDaily. ScienceDaily, 15 July 2014. <www.sciencedaily.com/releases/2014/07/140715214215.htm>.
Universitaet Tübingen. (2014, July 15). Glowing red in the big blue: Red fluorescence at great depths. ScienceDaily. Retrieved October 21, 2014 from www.sciencedaily.com/releases/2014/07/140715214215.htm
Universitaet Tübingen. "Glowing red in the big blue: Red fluorescence at great depths." ScienceDaily. www.sciencedaily.com/releases/2014/07/140715214215.htm (accessed October 21, 2014).

Share This



More Plants & Animals News

Tuesday, October 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

'Cadaver Dog' Sniffs out Human Remains

'Cadaver Dog' Sniffs out Human Remains

AP (Oct. 21, 2014) — Where's a body buried? Buster's nose can often tell you. He's a cadaver dog, specially trained to find human remains and increasingly being used by law enforcement and accepted in courts. These dogs are helping solve even decades-old mysteries. (Oct. 21) Video provided by AP
Powered by NewsLook.com
White Lion Cubs Born in Belgrade Zoo

White Lion Cubs Born in Belgrade Zoo

AFP (Oct. 20, 2014) — Two white lion cubs, an extremely rare subspecies of the African lion, were recently born at Belgrade Zoo. They are being bottle fed by zoo keepers after they were rejected by their mother after birth. Duration: 00:42 Video provided by AFP
Powered by NewsLook.com
Traditional Farming Methods Gaining Ground in Mali

Traditional Farming Methods Gaining Ground in Mali

AFP (Oct. 20, 2014) — He is leading a one man agricultural revolution in Mali - Oumar Diatabe uses traditional farming methods to get the most out of his land and is teaching others across the country how to do the same. Duration: 01:44 Video provided by AFP
Powered by NewsLook.com
Goliath Spider Will Give You Nightmares

Goliath Spider Will Give You Nightmares

Buzz60 (Oct. 20, 2014) — An entomologist stumbled upon a South American Goliath Birdeater. With a name like that, you know it's a terrifying creepy crawler. Sean Dowling (@SeanDowlingTV) has the details. Video provided by Buzz60
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins