.  .




.
Tweet
Marine plants can flee to avoid predators
by Staff Writers
Narragansett, RI (SPX) Oct 03, 2012

Measuring survival in the same experiments, the researchers found that fleeing helps the alga survive. Given a chance, the predators will eat all of the phytoplankton in one day if the algae have no safe place in which to escape, but they double every 48 hours if they have a refuge available to flee from predators. Fleeing makes the difference between life and death for this species, said Menden-Deuer.

Scientists at the University of Rhode Island's Graduate School of Oceanography have made the first observation of a predator avoidance behavior by a species of phytoplankton, a microscopic marine plant. Susanne Menden-Deuer, associate professor of oceanography, and doctoral student Elizabeth Harvey made the unexpected observation while studying the interactions between phytoplankton and zooplankton.

Their discovery will be published in the September 28 issue of the journal PLOS ONE.

"It has been well observed that phytoplankton can control their movements in the water and move toward light and nutrients," Menden-Deuer said. "What hasn't been known is that they respond to predators by swimming away from them. We don't know of any other plants that do this."

While imaging 3-dimensional predator-prey interactions, the researchers noted that the phytoplankton Heterosigma akashiwo swam differently in the presence of predators, and groups of them shifted their distribution away from the predators.

In a series of laboratory experiments, Menden-Deuer and Harvey found that the phytoplankton not only flee when in the presence of the predatory zooplankton, but they also flee when in water that had previously contained the predators. They found only a minimal effect when the phytoplankton were exposed to predators that do not feed on phytoplankton.

"The phytoplankton can clearly sense the predator is there. They flee even from the chemical scent of the predator but are most agitated when sensing a feeding predator," said Menden-Deuer.

When the scientists provided the phytoplankton with a refuge to avoid the predator - an area of low salinity water that the predators cannot tolerate - the phytoplankton moved to the refuge.

The important question these observations raise, according to Menden-Deuer, is how these interactions affect the survival of the prey species.

Measuring survival in the same experiments, the researchers found that fleeing helps the alga survive. Given a chance, the predators will eat all of the phytoplankton in one day if the algae have no safe place in which to escape, but they double every 48 hours if they have a refuge available to flee from predators. Fleeing makes the difference between life and death for this species, said Menden-Deuer.

"One of the puzzling things about some phytoplankton blooms is that they suddenly appear," she said. "Growth and nutrient availability don't always explain the formation of blooms. Our observation of algal fleeing from predators is another mechanism for how blooms could form. Amazingly, looking at individual microscopic behaviors can help to explain a macroscopic phenomenon."

The researchers say there is no way of knowing how common this behavior is or how many other species of phytoplankton also flee from predators, since this is the first observation of such a behavior.

"If it is common among phytoplankton, then it would be a very important process," Menden-Deuer said. "I wouldn't be surprised if other species had that capacity. It would be very beneficial to them."

In future studies, she hopes to observe these behaviors in the ocean and couple it with genetic investigations.

Funding for this research was provided by the National Science Foundation, the National Oceanic and Atmospheric Administration, and the U.S. Department of Agriculture. The study was conducted, in part, at the URI Marine Life Science Facility, which is supported by the Rhode Island Experimental Program to Stimulate Competitive Research.

Related Links
University of Rhode Island
Darwin Today At TerraDaily.com

Tweet



.
.
Get Our Free Newsletters Via Email
...
Buy Advertising Editorial Enquiries






.

. Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
 del.icio.us  Digg  Reddit Google



 Norway, Switzerland in push to protect 'environmental refugees'
Geneva (AFP) Oct 02, 2012
People forced to flee their countries by natural disasters find themselves in a legal vacuum where they are considered neither refugees nor migrants, Norway and Switzerland said Tuesday, as they launched an initiative aimed at protecting them. "Forced displacements in the context of natural disasters is a reality," said Walter Kaellin, envoy for the new Nansen Initiative, calling for "a more ... read more


Hong Kong seeks answers after deadly ferry crash

18 school children buried in China landslide

Argentine police protest after giant pay error

World facing unprecedented refugee crisis: UNHCR

HP stock sinks with slow turnaround

Malaysia hearing on Australia rare earths plant postponed

Ancient stinging nettles reveal Bronze Age trade connections

Probing the mysteries of cracks and stresses

The chemical memory of seawater

Now in Science: It's not too late for troubled fisheries

White shark diets vary with age and among individuals

Australia admits neglect of Great Barrier Reef

Australian tycoon fined for Arctic party cruise

Study: Arctic warming faster than before

Rudolph unfed loathes rain, dear

Melting Arctic ice cap at record low

New technologies advance livestock genomics for agricultural and biomedical uses

Superweeds linked to rising herbicide use in GM crops

Too Little Nitrogen May Restrain Carbon Storage Capability Of Plants

Tadpole Shrimp a New Rice Pest in the Midsouth

Typhoon Maliksi nearing Japan's northeast

Nigeria seasonal floods kill 148: Red Cross

Powerful typhoon hits Japan mainland

Typhoon Jelawat on course to hit mainland Japan

Ivory Coast opens first major trial of soldiers in political crisis

Nigeria seeks to end the curse of unfinished projects

France to facilitate Mali anti-rebel force

One-third of Lesotho faces food crisis: UN food agency

Compelling evidence that brain parts evolve independently

Anti-aging pill being developed

Human Brains Develop Wiring Slowly, Differing from Chimpanzees

Breaking up harder to do on Facebook


Tempur-Pedic Mattress Comparison

SPACE MEDIA NETWORK PROMOTIONS
Solar Energy Solutions
Memory Foam Mattress Review

Newsletters :: SpaceDaily Express :: SpaceWar Express :: TerraDaily Express :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News

.

The content herein, unless otherwise known to be public domain, are Copyright 1995-2012 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement

gipoco.com is neither affiliated with the authors of this page nor responsible for its contents. This is a safe-cache copy of the original web site.