Featured Research

from universities, journals, and other organizations

Sea Slug's Shopping Habits Dictated By Hunger, Scientists Report

Date:
April 7, 2000
Source:
University Of Illinois At Urbana-Champaign
Summary:
Conventional wisdom says that if you shop for groceries on an empty stomach you'll spend more than necessary because of impulse buying fed by hunger pangs, while a full stomach makes you a pickier shopper. You're in good company: Sea slugs shop the same way.

CHAMPAIGN, Ill. -- Conventional wisdom says that if you shop for groceries on an empty stomach you'll spend more than necessary because of impulse buying fed by hunger pangs, while a full stomach makes you a pickier shopper. You're in good company: Sea slugs shop the same way.

When hungry, the slugs (Pleurobranchaea californica) may ravenously attack even dangerous prey. With a full stomach, however, they actually turn away from and avoid potential food, scientists report in the March 28 issue of the Proceedings of the National Academy of Sciences. Such avoidance behavior is important for marine snails, because any time spent eating puts them at risk for being prey themselves.

The research was designed to study the mechanisms of decision-making, said Rhanor Gillette, a professor of physiology and neuroscience at the University of Illinois. Foraging animals and shopping humans should make decisions that produce the greatest benefit at the least cost. In this case, Gillette's team asked if degrees of appetite affected the readiness of snails to attack or avoid available prey. Responses were measured by the concentrations of food chemicals at which they would bite or turn away.

"What we've found in studying this very simple sea slug, with a very simple body form and a very simple brain, is that its behavior is organized hedonically, much like ours," he said. "If an animal's internal state changes, its responses to food and pain stimuli change, too. It is as if they make decisions based on a sliding scale of pleasure and pain. This is surprising for a simple invertebrate. Previously such behavior was thought to be exclusive to higher vertebrates."

Hungry snails tempted with the betaine -- a chemical found in most marine invertebrates that stimulates predators -- were quicker to strike than less hungry snails. Higher concentrations of betaine eventually induced biting by the satiated snails, but in general the less hungry snails withdrew their heads, turned and moved away from the food source.

Hungry snails also were more likely to try to attack a noxious acidic stimulus, researchers found. However, satiated snails avoided the noxious stimulus, and even hungry snails with previous exposure were more likely to avoid it. "This could reflect the need of the starving sea slug to pay a higher cost for a meal, if it had to overcome the defenses of prey unwilling to be eaten," Gillette said.

(To see a snail learning to avoid noxious prey, go to http://www.life.uiuc.edu/slugcity/movies.html. Click on "One Trial Learning.")

"We may have been looking at a very fundamental structural organization that will be found in the behavior of most foraging animals," he said. "Animals tend to make wise decisions when they forage, and they do so whether or not they have lots of brain power."


Story Source:

The above story is based on materials provided by University Of Illinois At Urbana-Champaign. Note: Materials may be edited for content and length.


Cite This Page:

University Of Illinois At Urbana-Champaign. "Sea Slug's Shopping Habits Dictated By Hunger, Scientists Report." ScienceDaily. ScienceDaily, 7 April 2000. <www.sciencedaily.com/releases/2000/04/000406092056.htm>.
University Of Illinois At Urbana-Champaign. (2000, April 7). Sea Slug's Shopping Habits Dictated By Hunger, Scientists Report. ScienceDaily. Retrieved October 2, 2014 from www.sciencedaily.com/releases/2000/04/000406092056.htm
University Of Illinois At Urbana-Champaign. "Sea Slug's Shopping Habits Dictated By Hunger, Scientists Report." ScienceDaily. www.sciencedaily.com/releases/2000/04/000406092056.htm (accessed October 2, 2014).

Share This



More Mind & Brain News

Thursday, October 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Pregnancy Spacing Could Have Big Impact On Autism Risks

Pregnancy Spacing Could Have Big Impact On Autism Risks

Newsy (Oct. 1, 2014) A new study says children born less than one year and more than five years after a sibling can have an increased risk for autism. Video provided by Newsy
Powered by NewsLook.com
Stopping School Violence

Stopping School Violence

Ivanhoe (Oct. 1, 2014) A trauma doctor steps out of the hospital and into the classroom to teach kids how to calmly solve conflicts, avoiding a trip to the ER. Video provided by Ivanhoe
Powered by NewsLook.com
Pineal Cysts: Debilitating Pain

Pineal Cysts: Debilitating Pain

Ivanhoe (Oct. 1, 2014) A tiny cyst in the brain that can cause debilitating symptoms like chronic headaches and insomnia, and the doctor who performs the delicate surgery to remove them. Video provided by Ivanhoe
Powered by NewsLook.com
Burning Away Brain Tumors

Burning Away Brain Tumors

Ivanhoe (Oct. 1, 2014) Doctors are 'cooking' brain tumors. Hear how this new laser-heat procedure cuts down on recovery time. Video provided by Ivanhoe
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins