Featured Research

from universities, journals, and other organizations

Living Upside-down Shapes Spiders For Energy Saving

Date:
March 26, 2008
Source:
Public Library of Science
Summary:
Consider the possible effects of the peculiar lifestyle of numerous spider species, which live, feed, breed and "walk" in an upside-down hanging position. According to new research, such "unconventional" enterprise drives a shape in spiders that confers high energy efficiency, as in oscillatory pendulums.

An "upside-down" spider, Uloborus sp. from Almería (Spain).
Credit: Eva De Mas

An interdisciplinary team of researchers from Spain and Croatia led an investigation into the peculiar lifestyle of numerous spider species, which live, feed, breed and 'walk' in an upside-down hanging position. According to their results, such 'unconventional' enterprise drives a shape in spiders that confers high energy efficiency, as in oscillatory pendulums.

Related Articles


The great majority of land animals evolved to use the ground as the main support for their motion. Accordingly, they evolved legs capable of supporting the weight of their whole bodies, enabling them to move around with their heads above their feet. However, many spider species found it more convenient to literally turn their world upside down. They spend most of their lives hanging suspended by their legs, and 'walk' by swinging under the influence of gravity.

Intrigued by this evolutionary phenomenon, a team of biologists from the Estación Experimental de Zonas Áridas (CSIC, Almería) in Spain, joined by an astrophysicist from the University of Split, Croatia, conducted an inquiry into biological advantages and caveats of such a peculiar lifestyle by studying over a hundred spider species. One of their focal questions was the evolutionary importance of 'bridging' -- the technique many spiders use to move between remote plants by building their own silk bridges, which they cross by 'walking' suspended upside-down from them.

Earlier research by other authors indicated that for monkeys this suspensory way of locomotion might be a more energetically efficient way of transportation than 'regular' walking on the ground. To this end, the authors took several spider species into the laboratory and compared how they handle two different types of movement - walking on the ground and bridging from branch to branch.

"We discovered that spiders that live upside-down have evolved disproportionately longer legs relative to 'normal' spiders, which enables them to move faster while bridging than while 'normally walking' on the ground. Particularly 'clumsy' walkers are larger spiders, because their long legs -- otherwise so convenient for bridging -- do not allow an easy lifting of their relatively large body mass" says Dr. Jordi Moya-Laraño from Spain, the principal investigator on this project.

For Dr. Dejan Vinkovi, astrophysicist from Croatia, this research is more than a biology study. "As a physicist, I was particularly interested in the energetics of upside-down locomotion" he says. "With this research we finally proved that the energetic efficiency of such motion stems from the same physical principle used to run the grandfather's clock -- motion of a pendulum under the influence of gravity."

Dr. Eulalia Moreno, co-author of the study, adds: "We started this collaboration with Dr. Moya-Laraño because I had studied the form and function of legs in tits, birds that, similarly to spiders, hang upside-down while foraging. Now, we have a much better understanding of how an animal shape should evolve when animals spent most of their lifetime hanging upside-down."

These results have implications for the evolution and ecology of spiders. For example, small spiders that hang from their webs should be able to leave their webs in search for prey by walking on the ground, as found in some tiny spiders, something that large spiders will be unable to do efficiently.

Journal reference: Moya-Laraño J, Vinkovi D, De Mas E, Corcobado G, Moreno E (2008) Morphological Evolution of Spiders Predicted by Pendulum Mechanics. PLoS One 3(3): e1841. doi:10.1371/journal.pone.0001841


Story Source:

The above story is based on materials provided by Public Library of Science. Note: Materials may be edited for content and length.


Cite This Page:

Public Library of Science. "Living Upside-down Shapes Spiders For Energy Saving." ScienceDaily. ScienceDaily, 26 March 2008. <www.sciencedaily.com/releases/2008/03/080325203450.htm>.
Public Library of Science. (2008, March 26). Living Upside-down Shapes Spiders For Energy Saving. ScienceDaily. Retrieved November 27, 2014 from www.sciencedaily.com/releases/2008/03/080325203450.htm
Public Library of Science. "Living Upside-down Shapes Spiders For Energy Saving." ScienceDaily. www.sciencedaily.com/releases/2008/03/080325203450.htm (accessed November 27, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Thursday, November 27, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Classic Hollywood Memorabilia Goes Under the Hammer

Classic Hollywood Memorabilia Goes Under the Hammer

Reuters - Entertainment Video Online (Nov. 26, 2014) — The iconic piano from "Casablanca" and the Cowardly Lion suit from "The Wizard of Oz" fetch millions at auction. Sara Hemrajani reports. Video provided by Reuters
Powered by NewsLook.com
Pet Dogs to Be Used in Anti-Ageing Trial

Pet Dogs to Be Used in Anti-Ageing Trial

Reuters - Innovations Video Online (Nov. 26, 2014) — Researchers in the United States are preparing to discover whether a drug commonly used in human organ transplants can extend the lifespan and health quality of pet dogs. Video provided by Reuters
Powered by NewsLook.com
From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

Newsy (Nov. 25, 2014) — The US FDA is announcing new calorie rules on Tuesday that will require everywhere from theaters to vending machines to include calorie counts. Video provided by Newsy
Powered by NewsLook.com
Feast Your Eyes: Lamb Chop Sent Into Space from UK

Feast Your Eyes: Lamb Chop Sent Into Space from UK

Reuters - Light News Video Online (Nov. 25, 2014) — Take a stab at this -- stunt video shows a lamb chop's journey from an east London restaurant over 30 kilometers into space. Rough Cut (no reporter narration). Video provided by Reuters
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

 

Plants & Animals

Earth & Climate

Fossils & Ruins

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