Navigation Links
New UF study shows some sharks follow 'mental map' to navigate seas
Date:3/9/2011

GAINESVILLE, Fla. A new study led by a University of Florida researcher uses tracking data of three shark species to provide the first evidence some of the fish swim directly to targeted locations.

Researchers found tiger and thresher sharks showed the ability to orient at large distances, with tiger sharks swimming in direct paths at least 4 miles away and reaching specific resource areas about 30 miles away, said lead author Yannis Papastamatiou, a marine biologist in the division of ichthyology at the Florida Museum of Natural History on the UF campus.

A research highlight of the study in the current edition of the Journal of Animal Ecology will appear in the Thursday issue of the journal Nature.

"This study is important because it uses quantitative methods to try to understand the underlying ecological reasons for animal movement," said Kevin Weng, a marine biologist at the University of Hawaii at Manoa. "Studies such as this one are stepping stones to achieving predictive skill for animal movement, and better understanding of navigation, population dynamics and ecology."

Papastamatiou said the study suggests the sharks have developed a 'mental map' of the area.

"There's been several studies that have shown that marine predators, like sharks, penguins, turtles and tunas, move using particular types of random walks, but there's going to be times when these animals don't move randomly," Papastamatiou said. "This study shows that at times sharks are able to orient to specific features, and in the case of tiger sharks, the distance over which they're performing those directed walks is likely larger than the distance of the immediate range of their sensory systems."

Researchers use the term "directed walk" to describe when a shark is moving toward a known goal rather than randomly swimming.

Researchers re-analyzed tracking data from acoustic transmitters on nine tiger sharks off the south shore of Oahu, Hawaii, in 1999, nine blacktip reef sharks in the lagoons of Palmyra Atoll in the Central Pacific Ocean in 2009, and 15 thresher sharks off the southern California coast in 2010. The animals were followed for at least seven hours and the statistical analysis determined whether the sharks were moving randomly or toward a known goal.

While tiger sharks have acute senses of sight, hearing and smell, their home range covers hundreds of square miles, including resource spots outside their sensory range. As bounce divers, they also almost continuously swim between the surface and about 250 to 330 feet below.

"At times these tiger sharks were swimming across a deep channel, open ocean, often at night," Papastamatiou said. "So the question is, 'What are they orienting to in such a seemingly featureless environment?' It really just highlights how impressive their navigation can be."

Researchers determined adult thresher sharks could orient at greater distances than juveniles, most likely because of their advanced development, Papastamatiou said. The study found blacktip reef sharks only traveled randomly, which has to do with their small home range compared to larger areas covered by thresher and tiger sharks.

Papastamatiou speculated the "mental map" the sharks create may have to do with their ability to sense magnetic fields.

"Probably the most interesting sense and still the most misunderstood is magnetic reception," Papastamatiou said. "There is an increasing amount of evidence that lots of, if not all animals, can to a certain degree detect magnetic fields. That is something that could potentially be used over very large distances because there are gradients in the earth's magnetic field and they could use those as landmarks so even swimming through open ocean, which seems featureless to us, may not be featureless to sharks if they could detect these magnetic fields."

He said the research would potentially be useful for obtaining accurate population dispersal models for the sharks so that movement patterns can be predicted after changes caused by fishing or the relocation of prey.


'/>"/>

Contact: Yannis Papastamatiou
ypapastamatiou@flmnh.ufl.edu
352-273-1955
University of Florida
Source:Eurekalert

Related biology news :

1. Long-term study shows effect of climate change on animal diversity
2. £2 million study to reveal workings of dementia genes
3. New study looks to define evangelicals and how they affect polling
4. CU-Boulder study suggests air quality regulations miss key pollutants
5. Researchers study acoustic communication in deep-sea fish
6. Study reveals homeowner perceptions in fire-prone areas
7. Researchers study how pistachios may improve heart health
8. Study: urban black bears live fast, die young
9. New study indicates link between weight gains during pregnancy and dieting history
10. Study reveals specific gene in adolescent men with delinquent peers
11. Sweat it out: UH study examines ability of sweat patches to monitor bone loss
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:5/3/2016)... Lithuania , May 3, 2016  Neurotechnology, ... released the MegaMatcher Automated Biometric Identification System ... of large-scale multi-biometric projects. MegaMatcher ABIS can process ... accuracy using any combination of fingerprint, face or ... MegaMatcher SDK and MegaMatcher Accelerator ...
(Date:4/19/2016)... 2016 The new GEZE SecuLogic ... web-based "all-in-one" system solution for all door components. It ... the door interface with integration authorization management system, and ... The minimal dimensions of the access control and the ... installations offer considerable freedom of design with regard to ...
(Date:3/31/2016)... RATON, Florida , March 31, 2016 ... LEGX ) ("LegacyXChange" or the "Company") ... for potential users of its soon to be launched ... video ( https://www.youtube.com/channel/UCyTLBzmZogV1y2D6bDkBX5g ) will also provide ... the use of DNA technology to an industry that ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... Md. , June 23, 2016 A person ... from the crime scene to track the criminal down. ... the U.S. Food and Drug Administration (FDA) uses DNA evidence ... Sound far-fetched? It,s not. The FDA ... sequencing to support investigations of foodborne illnesses. Put as simply ...
(Date:6/23/2016)...  The Biodesign Challenge (BDC), a university competition that ... living systems and biotechnology, announced its winning teams at ... New York City . The teams, ... at MoMA,s Celeste Bartos Theater during the daylong summit. ... curator of architecture and design, and Suzanne Lee ...
(Date:6/23/2016)... ... June 23, 2016 , ... In a new case report published today ... a patient who developed lymphedema after being treated for breast cancer benefitted from an ... paradigm for dealing with this debilitating, frequent side effect of cancer treatment. ...
(Date:6/23/2016)... 23, 2016 On Wednesday, June 22, ... down 0.22%; the Dow Jones Industrial Average edged 0.27% lower ... 2,085.45, down 0.17%. Stock-Callers.com has initiated coverage on the following ... Therapeutics (NASDAQ: NKTR ), Aralez Pharmaceuticals Inc. (NASDAQ: ... BIND ). Learn more about these stocks by accessing ...
Breaking Biology Technology: