Featured Research

from universities, journals, and other organizations

Scientists Pinpoint How Fish Save Energy By Swimming In Schools

Date:
January 5, 2004
Source:
Massachusetts Institute Of Technology
Summary:
Using a tank designed to mimic a turbulent waterway, scientists have found that fish use a unique and clever swimming motion to harness the energy of eddies in flowing water. By essentially hitching a ride and letting these vortices propel them along, the scientists say, fish can swim against a current with considerably less exertion than is required in calmer settings.

Using a tank designed to mimic a turbulent waterway, scientists have found that fish use a unique and clever swimming motion to harness the energy of eddies in flowing water. By essentially hitching a ride and letting these vortices propel them along, the scientists say, fish can swim against a current with considerably less exertion than is required in calmer settings.

Related Articles


The study provides the first direct view of the technique used by fish to exploit the energy of eddies generated by the swimming movements of other members of a school.

The work, reported in the Nov. 28 issue of Science by researchers from MIT and Harvard, could have many engineering applications, from the design of better fish ladders and passageways at hydroelectric dams to autonomous underwater vehicles capable of negotiating turbulent flows in natural habitats.

“This study reveals mechanisms through which the energy contained in the ed-dies of turbulence can be extracted, with great reduction in the required swim-ming effort,” said Michael S. Triantafyllou, a professor in MIT’s Department of Ocean Engineering. “Since turbulence is present everywhere in moving water or air -- in the ocean, the lakes, and streams, as well as the atmosphere -- many op-portunities arise for engineering applications of these new principles of energy extraction.”

First author James C. Liao, a graduate student in Harvard’s Department of Or-ganismic and Evolutionary Biology, likens the technique fish use to swim against a turbulent current to tacking, the back-and-forth motion that allows a sailboat to move forward passively, if somewhat indirectly, against a breeze.

The researchers looked at animal behavior and the physics of water flow. They placed an ordinary cylinder in a flow tank to create eddies similar to those gen-erated in the wild by the flow of water past submerged branches or coral reef formations, or the propulsive movements of other fish, and then recorded the muscle activity of trout as they swam among the vortices generated downstream from the cylinder.

They discovered a previously unknown swimming motion, dubbed the “Karman gait,” that exploits the energy of eddies to minimize fish muscle activity. Viewed from below, the bodies of fish swimming in turbulent waters flutter gently, like a flag flapping in the breeze, a motion that entails far less muscle activity than swimming through still waters.

“This new link between the use of eddies and decreased muscle activity supports a hydrodynamic explanation for fish distributions in schools and in current-swept habitats,” Liao said. “Our work is the first to establish a causal mechanism to explain the hydrodynamic benefits of fish schooling, and resolves the paradox of how wild fish can move upstream against currents faster than they have been reported to swim in the laboratory.”

Additional authors of the paper are George V. Lauder, a professor of biology at Harvard, and MIT alumnus David N. Beal (S.M. 1997, Ph.D. 2003). The work was supported by grants from Sigma Xi, the American Museum of Natural History, the Robert A. Chapman Memorial Scholarship at Harvard, the National Science Foundation, and MIT Sea Grant.


Story Source:

The above story is based on materials provided by Massachusetts Institute Of Technology. Note: Materials may be edited for content and length.


Cite This Page:

Massachusetts Institute Of Technology. "Scientists Pinpoint How Fish Save Energy By Swimming In Schools." ScienceDaily. ScienceDaily, 5 January 2004. <www.sciencedaily.com/releases/2004/01/040105072113.htm>.
Massachusetts Institute Of Technology. (2004, January 5). Scientists Pinpoint How Fish Save Energy By Swimming In Schools. ScienceDaily. Retrieved December 22, 2014 from www.sciencedaily.com/releases/2004/01/040105072113.htm
Massachusetts Institute Of Technology. "Scientists Pinpoint How Fish Save Energy By Swimming In Schools." ScienceDaily. www.sciencedaily.com/releases/2004/01/040105072113.htm (accessed December 22, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Monday, December 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Earthworms Provide Cancer-Fighting Bacteria

Earthworms Provide Cancer-Fighting Bacteria

Reuters - Innovations Video Online (Dec. 21, 2014) Polish scientists isolate bacteria from earthworm intestines which they say may be used in antibiotics and cancer treatments. Suzannah Butcher reports. Video provided by Reuters
Powered by NewsLook.com
Existing Chemical Compounds Could Revive Failing Antibiotics, Says Danish Scientist

Existing Chemical Compounds Could Revive Failing Antibiotics, Says Danish Scientist

Reuters - Innovations Video Online (Dec. 21, 2014) A team of scientists led by Danish chemist Jorn Christensen says they have isolated two chemical compounds within an existing antipsychotic medication that could be used to help a range of failing antibiotics work against killer bacterial infections, such as Tuberculosis. Jim Drury went to meet him. Video provided by Reuters
Powered by NewsLook.com
Researchers Test Colombian Village With High Alzheimer's Rates

Researchers Test Colombian Village With High Alzheimer's Rates

AFP (Dec. 19, 2014) In Yarumal, a village in N. Colombia, Alzheimer's has ravaged a disproportionately large number of families. A genetic "curse" that may pave the way for research on how to treat the disease that claims a new victim every four seconds. Duration: 02:42 Video provided by AFP
Powered by NewsLook.com
Monarch Butterflies Descend Upon Mexican Forest During Annual Migration

Monarch Butterflies Descend Upon Mexican Forest During Annual Migration

Reuters - Light News Video Online (Dec. 19, 2014) Millions of monarch butterflies begin to descend onto Mexico as part of their annual migration south. Rough Cut (no reporter narration) Video provided by Reuters
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