Featured Research

from universities, journals, and other organizations

Crab Claws Pack Strengthening Bromide-rich Biomaterial

Date:
March 6, 2009
Source:
University of Oregon
Summary:
Next time you have an unlucky encounter with a crab's pincers, consider that the claw tips may be reinforced with bromine-rich biomaterial 1.5 times harder than acrylic glass and extremely fracture resistant.

Dungeness crab. A bromine-rich biomaterial 1.5 times harder than acrylic glass empowers the claw tips of the striped shore crab as the pinchers pick and hold prey. It also is present on the walking legs of Dungeness crabs.
Credit: iStockphoto/Robert Koopmans

Next time you have an unlucky encounter with a crab's pinchers, consider that the claw tips may be reinforced with bromine-rich biomaterial 1.5 times harder than acrylic glass and extremely fracture resistant, says a University of Oregon scientist.

Residents on the U.S. West Coast may have had close encounters with the biomaterial -- detailed by a seven-member team in a paper published online in advance of regular publication in the Journal of Structural Biology. The translucent substance empowers the claw tips of the striped (or lined) shore crab (Pachygrapsus cassipes) as the pinchers pick and hold prey. It also is present on the walking legs of Dungeness crabs (Cancer magister), a dining delicacy in the Pacific Northwest.

"The types of crabs that use this trick for their claw tips rely on the tips fitting together like forceps in order to pick and hold bits of food, and fracture damage could make the tips useless," said the study's lead author Robert Schofield, a researcher in the UO physics department. "These crabs include many common crabs such as hermit crabs, which have one large claw for crushing, and a small claw tipped with this newly discovered biomaterial for finer work."

The claws of the Dungeness crab, he noted, are designed for crushing instead of fine manipulations, and are not tipped with this material. But their legs are, he said.

"The next time you are eating a Dungeness crab, notice that the sharp tip of the leg is a cap of translucent material that is very different from the rest of the crab," he said. "Notice how difficult it is to break the tip, even though it is very thin. This biomaterial can bend six times further before breaking than the material used in other regions. If the tip were made of the same material as the rest of the crab, it could never stay sharp and the crab would have difficulty clinging."

This bromine-rich material at the tips of crab claws and legs is a new member of a class of structural biomaterials that employ heavy atoms like zinc, iodine and iron. "It's not yet clear why heavy elements are used," Schofield said. "Perhaps the mass of the atoms themselves plays a role in damping vibrations that can lead to fracture."

These heavy-element biomaterials had escaped notice until now because they are typically employed by small organisms such as insects. Schofield was lead author of a study published in 2001 that had identified their presence in mandibular teeth, tarsal claws, stings and other such tools of small organisms.

In order to measure the mechanical properties of these tiny structures, the researchers had to develop machines and techniques that would work for tiny samples.

"It turns out that fracture tends to be a bigger problem for small organisms than for large ones," Schofield said. "Humans are just starting to try to engineer tiny machines and tools, and we have a lot still to learn from organisms that have coped with being small for millions of years."

Co-authors with Schofield on the National Science Foundation-supported research were UO undergraduate student Jack C. Niedbala, Michael H. Nesson of Oregon State University, Ye Tao of the Chinese Academy of Sciences in Beijing, Jacob E. Stokes and Robert A. Scott of the University of Georgia, and Matthew J. Latimer of the Stanford Synchrotron Radiation Laboratory.


Story Source:

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


Cite This Page:

University of Oregon. "Crab Claws Pack Strengthening Bromide-rich Biomaterial." ScienceDaily. ScienceDaily, 6 March 2009. <www.sciencedaily.com/releases/2009/02/090225132532.htm>.
University of Oregon. (2009, March 6). Crab Claws Pack Strengthening Bromide-rich Biomaterial. ScienceDaily. Retrieved July 25, 2014 from www.sciencedaily.com/releases/2009/02/090225132532.htm
University of Oregon. "Crab Claws Pack Strengthening Bromide-rich Biomaterial." ScienceDaily. www.sciencedaily.com/releases/2009/02/090225132532.htm (accessed July 25, 2014).

Share This




More Matter & Energy News

Friday, July 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

TSA Administrator on Politics and Flight Bans

TSA Administrator on Politics and Flight Bans

AP (July 24, 2014) TSA administrator, John Pistole's took part in the Aspen Security Forum 2014, where he answered questions on lifting of the ban on flights into Israel's Tel Aviv airport and whether politics played a role in lifting the ban. (July 24) Video provided by AP
Powered by NewsLook.com
Creative Makeovers for Ugly Cellphone Towers

Creative Makeovers for Ugly Cellphone Towers

AP (July 24, 2014) Mobile phone companies and communities across the country are going to new lengths to disguise those unsightly cellphone towers. From a church bell tower to a flagpole, even a pencil, some towers are trying to make a point. (July 24) Video provided by AP
Powered by NewsLook.com
Algonquin Power Goes Activist on Its Target Gas Natural

Algonquin Power Goes Activist on Its Target Gas Natural

TheStreet (July 23, 2014) When The Deal's Amanda Levin exclusively reported that Gas Natural had been talking to potential suitors, the Ohio company responded with a flat denial, claiming its board had not talked to anyone about a possible sale. Lo and behold, Canadian utility Algonquin Power and Utilities not only had approached the company, but it did it three times. Its last offer was for $13 per share as Gas Natural's was trading at a 60-day moving average of about $12.50 per share. Now Algonquin, which has a 4.9% stake in Gas Natural, has taken its case to shareholders, calling on them to back its proposals or, possibly, a change in the target's board. Video provided by TheStreet
Powered by NewsLook.com
Robot Parking Valet Creates Stress-Free Travel

Robot Parking Valet Creates Stress-Free Travel

AP (July 23, 2014) 'Ray' the robotic parking valet at Dusseldorf Airport in Germany lets travelers to avoid the hassle of finding a parking spot before heading to the check-in desk. (July 23) Video provided by AP
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:
from the past week

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