Navigation Links
Insects are scared to death of fish
Date:10/27/2011

TORONTO, ON -- The mere presence of a predator causes enough stress to kill a dragonfly, even when the predator cannot actually get at its prey to eat it, say biologists at the University of Toronto.

"How prey respond to the fear of being eaten is an important topic in ecology, and we've learned a great deal about how these responses affect predator and prey interactions," says Professor Locke Rowe, chair of the Department of Ecology and Evolutionary Biology (EEB) and co-principal investigator of a study conducted at U of T's Koffler Scientific Reserve.

"As we learn more about how animals respond to stressful conditions whether it's the presence of predators or stresses from other natural or human-caused disruptions we increasingly find that stress brings a greater risk of death, presumably from things such as infections that normally wouldn't kill them," says Rowe.

Shannon McCauley, a post-doctoral fellow, and EEB professors Marie-Jose Fortin and Rowe raised juvenile dragonfly larvae (Leucorrhinia intacta) in aquariums or tanks along with their predators. The two groups were separated so that while the dragonflies could see and smell their predators, the predators could not actually eat them.

"What we found was unexpected - more of the dragonflies died when predators shared their habitat," says Rowe. Larvae exposed to predatory fish or aquatic insects had survival rates 2.5 to 4.3 times less than those not exposed.

In a second experiment, 11 per cent of larvae exposed to fish died as they attempted to metamorphose into their adult stage, compared to only two per cent of those growing in a fish-free environment. "We allowed the juvenile dragonflies to go through metamorphosis to become adult dragonflies, and found those that had grown up around predators were more likely to fail to complete metamorphosis successfully, more often dying in the process," says Rowe.

The scientists suggest that their findings could apply to all organisms facing any amount of stress, and that the experiment could be used as a model for future studies on the lethal effects of stress.

The research is described in a paper titled "The deadly effects of 'nonlethal' predators", published in Ecology and highlighted in Nature this week. It was supported by grants to Fortin and Rowe from the Canada Research Chairs program and the Natural Sciences and Engineering Research Council of Canada, and a post-doctoral fellowship awarded to McCauley.


'/>"/>
Contact: Sean Bettam
s.bettam@utoronto.ca
416-946-7950
University of Toronto
Source:Eurekalert  

Related medicine news :

1. Diet of contaminated insects harms endangered meat-eating plants
2. How pest insects might adapt to climate change, affecting agriculture and health
3. Insects that deter predators produce fewer offspring
4. Premature Death Could Await Obese Kids
5. Most maternal deaths in sub-Saharan Africa could be avoided
6. Cleveland Medical Malpractice Attorney Obtains Settlement in Wrongful Death Case
7. American Stroke Association Late-Breaking Science Report: Surgery, Stenting to Open Blocked Neck Arteries Similar in Safety, Efficacy, But Show Differences in Stroke, Heart Attack and Death Rates at Certain Ages
8. Hormone thought to slow aging associated with increased risk of cancer death
9. Some Parents Consider Hastening a Sick Childs Death
10. New tool to predict early death or hospital readmission
11. Death After Discharge Rates Higher in Elderly ICU Patients
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Insects are scared to death of fish
(Date:5/27/2016)... ... ... Southland Log Homes , designer and manufacturer of America’s Favorite Log ... be found on its website at SouthlandLogHomes.com. , The designs of the wood ... craftsmanship of timber post and beam construction. The result is a barn that ...
(Date:5/27/2016)... York, NY (PRWEB) , ... May 27, 2016 , ... ... factors of a stroke, which we as a society can control and change. , ... stroke occurs nearly every 40 seconds within the United States. Plus, with an estimated ...
(Date:5/27/2016)... ... May 27, 2016 , ... Aimed at nurses and employees ... which come courtesy of leaders in the nursing and health care industry. It also ... and associations—namely Abilene Christian University. , As the nursing industry is coming out ...
(Date:5/26/2016)... Hampshire (PRWEB) , ... May 26, 2016 , ... ... care products, has been honored with a 2016 When Work Works Award for its ... award, part of the national When Work Works project administered by the Families and ...
(Date:5/26/2016)... ... ... On Memorial Day, Hope For Heroes and USA Medical Card ... the country. The nonprofit Hope For Heroes partnered with the leading provider of ... disabled military veterans, as well as police, firemen, and EMS professionals across the country, ...
Breaking Medicine News(10 mins):
(Date:5/26/2016)... TARE (Transarterial Radio-embolization) Using ... and Overall Decreased Use of Hospital Resource ... specialist healthcare company, has today announced the publication ... of ISPOR (International Society for Pharmacoeconomics and Outcomes ... using yttrium-90 glass microspheres is associated with cost ...
(Date:5/25/2016)... , May 25, 2016 According ... by Type (3D, 2D, 4D), by Therapeutic Area (Oncology, ... End User (Medical Device Manufacturers, Hospitals/ Clinics) - Forecast ... global Medical Animation Market for the forecast period of ... USD 301.3 Million by 2021 from USD 117.3 Million ...
(Date:5/25/2016)... , May 25, 2016  According to Kalorama Information, ... billion in 2015.  Though these are challenging times ... opportunity for success for companies that remain optimistic ... of new growth prospects medical device companies spend ... and development (R&D) than do companies in other ...
Breaking Medicine Technology: