Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Switching Senses

02.11.2011
Caltech biologists find that leeches shift the way they locate prey in adulthood

Many meat-eating animals have unique ways of hunting down a meal using their senses. To find a tasty treat, bats use echolocation, snakes rely on infrared vision, and owls take advantage of the concave feathers on their faces, the better to help them hear possible prey. Leeches have not just one but two distinct ways of detecting dinner, and, according to new findings from biologists at the California Institute of Technology (Caltech), their preferred method changes as they age.

Medicinal leeches, like many aquatic animals, use water disturbances to help them find a meal. Juvenile leeches eat the blood of fish and amphibians, while adults opt for blood meals from the more nutritious mammals. Since it was known that leeches change their food sources as they develop, the Caltech team wanted to know if the way they sense potential food changed as well. Their findings are outlined in a paper now available online in the Journal of Experimental Biology.

The group set up experiments to test how much leeches rely on each of the two sensory modalities they use to find food: hairs on their bodies that can note disturbances in the water made by prey moving through it and simple eyes that can pick up on the passing shadows that those waves make. They monitored both juvenile and adult leeches as they reacted to mechanical waves in a tank of water or to passing shadows, as well as to a combination of the two stimuli. The leeches in both age groups responded in similar ways when only one stimulus was present. But when both waves and shadows existed, the adult leeches responded solely to the waves.

"We knew that there was a developmental switch in what kind of prey they go after," says Daniel Wagenaar, senior author of the paper and Broad Senior Research Fellow in Brain Circuitry at Caltech. "So when we saw a difference in the source of disturbances that the juveniles go after relative to the adults, we thought 'great—it's probably matching what we know.'"

However, the team was very surprised to see that the individual sensory modalities aren't modified during development to help decipher different types of prey. The leech's visual system doesn't really change as the animal matures; neither does the mechanical system. What does change, however, is the integration of the visual and mechanical cues to make a final behavioral decision.

"As they mature, the animals basically start paying attention to one sense more than the other," explains Cynthia Harley, lead author of the study and a postdoctoral scholar in biology at Caltech. She says that the team will now focus their studies on the adult leeches to learn more about how this sensory information is processed both at the behavioral and cellular levels.

Paper coauthor Javier Cienfuegos, now a freshman at Yale, contributed to the study while a high school student at the Polytechnic School, which is located next to Caltech's campus. He ran about half of the experimental trials and was "instrumental in the success of the study," says Harley.

The research outlined in the paper, "Developmentally regulated multisensory integration for prey localization in the medicinal leech," was funded by the Burroughs Wellcome Fund and the Broad Foundations.

Deborah Williams-Hedges
626-395-3227
debwms@caltech.edu

Deborah Williams-Hedges | EurekAlert!
Further information:
http://www.caltech.edu

More articles from Life Sciences:

nachricht More genes are active in high-performance maize
19.01.2018 | Rheinische Friedrich-Wilhelms-Universität Bonn

nachricht How plants see light
19.01.2018 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Artificial agent designs quantum experiments

On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.

We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

Im Focus: Room-temperature multiferroic thin films and their properties

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.

Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Let the good tubes roll

19.01.2018 | Materials Sciences

How cancer metastasis happens: Researchers reveal a key mechanism

19.01.2018 | Health and Medicine

Meteoritic stardust unlocks timing of supernova dust formation

19.01.2018 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>