Navigation Links
Time of day tempers tadpoles' response to predators

To a tiny tadpole, life boils down to two basic missions: eat, and avoid being eaten. But there's a trade-off. The more a tadpole eats, the faster it grows big enough to transform into a frog; yet finding food requires being active, which ups the odds of becoming someone else's dinner.

Scientists have known that prey adjust their activity levels in response to predation risk, but new research by a University of Michigan graduate student shows that internal factors, such as biorhythms, temper their responses.

Michael Fraker, a doctoral student in the laboratory of ecology and evolutionary biology professor Earl Werner, will present his results Aug. 10 at a meeting of the Ecological Society of America in Memphis, Tenn.

Fraker studied tadpoles of the green frog (Rana clamitans), which normally feed more at night, to see whether their responses to predatory dragonfly larvae differed with time of day.

"Green frog tadpoles, like many other aquatic animals, assess predation risk indirectly by sensing chemicals released by their predators into the water," Fraker said. Typically, the tadpoles respond to such cues by swimming down to the bottom, seeking shelter and remaining still. In his experiments, Fraker exposed tadpoles in a tank to the chemical signatures of dragonfly larvae for one hour during the day and one hour at night. Then he recorded their swimming and feeding activity during and after exposure. Both during the day and at night, the tadpoles initially responded similarly to the chemical cues, showing the typical plunge in activity. But at night they returned to feeding more quickly than during the day.

"My interpretation of these results is that green frog tadpoles behave more conservatively in response to a predator chemical cue during the day because predation risk may still be fairly high and the tadpoles are going to feed very little anyway. That means the growth rate-to-predation risk ratio is low. At night, the ratio is higher because that's when the tadpoles do most of their feeding. This favors a quicker return to their pre-cue activity levels."

Considering biorhythmic activity patterns in predator-prey studies is something of a new slant, Fraker said. "The main implication of my results is that prey behavior can be influenced by both external factors---the chemical cues released by the predators---and internal factors such as circadian rhythms. This is important for understanding the mechanisms of prey behavior, which need to be identified in order to make long-term predictions about the effects of prey behavior in ecological communities."


'"/>

Source:University of Michigan


Related biology news :

1. Poplar trees redirect resources in response to simulated attack
2. A comprehensive response to HIV could prevent 10 million AIDS deaths in Africa by 2020
3. Scientists solve structure of key protein in innate immune response
4. Harmful chemicals may reprogram gene response to estrogen
5. Mouse with designer liver has enhanced glucose tolerance, insulin response
6. A protein in the eye may prevent immune response and protect eyes from disease
7. Scientists at Galileo Pharmaceuticals confirm inflammatory response linked to glucose levels
8. Bacteria use hosts immune response to their competitive advantage
9. New protein vital for immune response is found in surprise location
10. NIH renews network focused on how genes influence drug responses
11. Engineered molecule amplifies bodys immune response
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:4/24/2017)... Janice Kephart , former 9/11 ... Partners, LLP (IdSP) , today issues the following ... March 6, 2017 Executive Order: Protecting the ... be instilled with greater confidence, enabling the reactivation ... applications are suspended by until at least July ...
(Date:4/17/2017)... NXT-ID, Inc. (NASDAQ: NXTD ) ("NXT-ID" ... its 2016 Annual Report on Form 10-K on Thursday April 13, ... ... the Investor Relations section of the Company,s website at http://www.nxt-id.com ... http://www.sec.gov . 2016 Year Highlights: ...
(Date:4/11/2017)... Fla. , April 11, 2017 ... and secure authentication solutions, today announced that it ... Intelligence Advanced Research Projects Activity (IARPA) to develop ... Thor program. "Innovation has been a ... IARPA,s Thor program will allow us to innovate ...
Breaking Biology News(10 mins):
(Date:10/11/2017)... ... October 11, 2017 , ... The CRISPR-Cas9 ... overexpression experiments and avoiding the use of exogenous expression plasmids. The simplicity of ... performing systematic gain-of-function studies. , This complement to loss-of-function studies, such as ...
(Date:10/11/2017)... and LAGUNA HILLS, Calif. , Oct. ... Cancer Research, London (ICR) and University ... SKY92, SkylineDx,s prognostic tool to risk-stratify patients with multiple myeloma ... MUK nine . The University of Leeds ... partly funded by Myeloma UK, and ICR will perform the ...
(Date:10/10/2017)... ... October 10, 2017 , ... ... advancing targeted antibody-drug conjugate (ADC) therapeutics, today confirmed licensing rights that give ... Liposomal Nanoparticle), a technology developed in collaboration with Children’s Hospital Los Angeles ...
(Date:10/10/2017)... ... October 10, 2017 , ... USDM Life Sciences , ... life sciences and healthcare industries, announces a presentation by Subbu Viswanathan and Jennifer ... “Automating GxP Validation for Agile Cloud Platforms,” will present a revolutionary approach to ...
Breaking Biology Technology: