Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Octopuses Have a Unique Way to Control Their 'Odd' Forms

20.04.2015

New Research from Hebrew University of Jerusalem's Octopus Research Group

The body plan of octopuses is nothing if not unique, with a sophisticated brain in a soft, bilaterally symmetrical body, encircled by eight radially symmetrical and incredibly flexible arms.


Mapping how octopuses control their movement: Dr. Guy Levy (L) and Prof. Benny Hochner at the Hebrew University of Jerusalem's Octopus Research Group. For videos, see below. (Photo: Hebrew University)

Now, reporting the first detailed kinematic analysis of octopus arm coordination in crawling, researchers from the Hebrew University of Jerusalem show that the animals have a unique motor control strategy to match their “odd” form. The researchers report their findings in the Cell Press journal Current Biology.

“Octopuses use unique locomotion strategies that are different from those found in other animals,” says Prof. Binyamin (Benny) Hochner, Principal Investigator at the Hebrew University of Jerusalem's Octopus Research Group. “This is most likely due to their soft molluscan body that led to the evolution of ‘strange’ morphology, enabling efficient locomotion control without a rigid skeleton.”

Earlier studies of octopus behavior by the Hebrew University team have focused on goal-directed arm movements, like reaching to a target or fetching food to the mouth, Hochner explains.

(See, for instance, http://www.eurekalert.org/pub_releases/2006-04/cp-hto041306.php , http://www.eurekalert.org/pub_releases/2014-05/cp-hod050714.php , and

http://www.eurekalert.org/pub_releases/2011-05/thuo-hur051811.php   ). The new study is the first to tackle a larger question: how octopuses manage to coordinate their eight long, flexible arms during locomotion.

Octopuses most likely evolved from animals more similar to clams, with a protective outer shell and almost no movement to speak of. “During evolution, octopuses lost their heavy protective shells and became more maneuverable on the one hand, but also more vulnerable on the other hand,” says Hebrew University co-author Dr. Guy Levy, of the Department of Neurobiology and the Edmond & Lily Safra Center for Brain Sciences. “Their locomotory abilities evolved to be much faster than those of typical molluscs, probably to compensate for the lack of shell.”

The evolution of a typical snail’s foot into long and slender arms gave octopuses extraordinary flexibility. Excellent vision, together with a highly developed and large brain and the ability to color camouflage, made cephalopods very successful hunters. But how do they control the movements of those remarkable bodies?

After poring over videos of octopuses in action, frame by frame, the researchers made several surprising discoveries. Despite its bilaterally symmetrical body, the octopus can crawl in any direction relative to its body orientation. The orientation of its body and crawling direction are independently controlled, and its crawling lacks any apparent rhythmical patterns in limb coordination.

Hochner, Levy, and their colleagues show that this uncommon maneuverability of octopuses is derived from the radial symmetry of their arms around the body and the simple mechanism by which the arms create the crawling thrust: pushing-by-elongation.

“These two together enable a mechanism whereby the central controller chooses in a moment-to-moment fashion which arms to recruit for pushing the body in an instantaneous direction,” the researchers write. The animal needs only to choose which arms to activate in order to determine the direction of locomotion.

The findings lend support to what’s known as the Embodied Organization concept. In the traditional view, motor-control strategies are devised to fit the body. But, the researchers say, under Embodied Organization, the control and the body evolve together in lockstep within the context of the environment with which those bodies interact.

“This concept, which is borrowed from robotics, argues that the optimal behavior of an autonomous robot or an animal is achieved as a result of the optimization of the reciprocal and dynamical interactions between the brain, body, and the constantly changing environment, thus leading to optimal adaptation of the system, as a whole, to its ecological niche,” Levy says. “Another important virtue of this type of organization is that every level, including the physical properties and the morphology, contribute to the control of the emerging behavior—and not only the brain, as we tend to think.”

Levy and Hochner say their next step is to uncover the neural circuits involved in the octopuses’ coordinated crawling.

The research was supported by the European Commission EP-7 projects OCTOPUS and STIFF-FLOP.

Videos accompanying this press release are available for download at:
http://media.huji.ac.il/new/multimedia/hu150516_LevyOctopusCrawling_MovieS1.mp4
http://media.huji.ac.il/new/multimedia/hu150516_LevyOctopusCrawling_MovieS2.mp4
http://media.huji.ac.il/new/multimedia/hu150516_LevyOctopus.mp4
(CREDIT: Videos courtesy Dr. Guy Levy / Hebrew University Octopus Research Group)

Original press release text courtesy of Cell Press.

To contact the researchers:

Prof. Benny Hochner: Benny.Hochner@mail.huji.ac.il
Dr. Guy Levy: Guy.Levy@mail.huji.ac.il

Media contact:

Dov Smith
The Hebrew University of Jerusalem
+972-2-5882844 / +972-54-8820860
dovs@savion.huji.ac.il

Dov Smith | Hebrew University

Further reports about: Hebrew University locomotion mechanism morphology movements octopus octopuses

More articles from Life Sciences:

nachricht Toward a 'smart' patch that automatically delivers insulin when needed
18.01.2017 | American Chemical Society

nachricht 127 at one blow...
18.01.2017 | Stiftung Zoologisches Forschungsmuseum Alexander Koenig, Leibniz-Institut für Biodiversität der Tiere

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

A big nano boost for solar cells

18.01.2017 | Power and Electrical Engineering

Glass's off-kilter harmonies

18.01.2017 | Materials Sciences

Toward a 'smart' patch that automatically delivers insulin when needed

18.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>