Obstacles no barrier to higher speeds for worms, researchers find

Feb 08, 2012
Caenorhabditis elegans. Image: Wikipedia.

Obstacles in an organism's path can help it to move faster, not slower, researchers from New York University's Applied Math Lab at the Courant Institute of Mathematical Sciences have found through a series of experiments and computer simulations. Their findings, which appear in the Journal of the Royal Society Interface, have implications for a better understanding of basic locomotion strategies found in biology, and the survival and propagation of the parasite that causes malaria.

Nematodes, which are very small worms, and many other organisms use a snake-like, undulatory motion to propel forward across dry surfaces and through fluids. There are, however, many instances where small organisms must make their way through a fluid-filled environment studded with obstacles that are comparable in size to the swimmers themselves. Nearly all microscopic nematodes, about one millimeter in length, face such barriers when moving through —the soil's granules serve as hurdles these creatures must navigate. Similarly, the malaria parasite's male gametes, or reproductive cells, must swim through a dense suspension of their host's blood cells in order to procreate. A similar situation arises for spermatozoa moving through the reproductive tract.

In the Journal of the Royal Society Interface study, the Applied Math Lab (AML) group sought to understand how efficiently such undulating organisms can move through obstacle-laden fluids. To do so, they conducted a study comparing experiments using live worms, the nematode C. elegans, with the results of a computer model of a worm moving in a virtual environment. In the experiment, the worms swam through a very shallow pool filled with a lattice of obstructing micro-pillars while the computer simulation gave a benchmark of a worm moving blindly without sensing and response.

Surprisingly, C. elegans was able to advance much more quickly through the lattice of obstacles than through a fluid in which their movement was unimpeded.

"If the lattice is neither too tight nor too loose, the worms move much faster by threading between and pushing off the pillars," the researchers wrote.

The second surprise was that the computer simulation gave very similar results, reproducing the fast motions of the worm in the lattice, but also showing complex "life-like" behaviors that had been interpreted as coming from sensing and response of the worm to its local environment.

These results enhance our understanding of biological locomotion through tortuous environments like soils or the reproductive tract, showing how real can take advantage of what seems a defiant complexity, and offer intriguing insights into how the reproductive processes of dangerous might be interrupted.

Explore further: Study shows exception to rule of lifespan for fliers, burrowers and tree dwellers

Related Stories

New devices to boost nematode research on neurons and drugs

Feb 06, 2008

A pair of new thin, transparent devices, constructed with soft lithography, should boost research in which nematodes are studied to explore brain-behavior connections and to screen new pharmaceuticals for potential treatment ...

Elusive prey

Jul 28, 2011

Escape responses are some of the most studied behaviors by neurobiologists who want to understand how the brain processes sensory information. The ability to evade predators plays a vital role in the process of natural selection. ...

Exploring the characteristics of viscoelastic fluids

Feb 04, 2010

(PhysOrg.com) -- There are many microorganisms out there, navigating through complex biological fluids. “One of the most common migrations takes place with spermatozoa as it navigates the female reproductive tract,” Joseph ...

Recommended for you

Chimpanzees prefer firm, stable beds

3 hours ago

Chimpanzees may select a certain type of wood, Ugandan Ironwood, over other options for its firm, stable, and resilient properties to make their bed, according to a study published April 16, 2014 in the open-access ...

Offspring benefit from mum sending the right message

11 hours ago

(Phys.org) —Researchers have uncovered a previously unforeseen interaction between the sexes which reveals that offspring survival is affected by chemical signals emitted from the females' eggs.

Lemurs match scent of a friend to sound of her voice

Apr 15, 2014

Humans aren't alone in their ability to match a voice to a face—animals such as dogs, horses, crows and monkeys are able to recognize familiar individuals this way too, a growing body of research shows.

User comments : 3

Adjust slider to filter visible comments by rank

Display comments: newest first

hyongx
not rated yet Feb 08, 2012
Now that the worms are fast, we just need to grow them very large and give them teeth. then,
voila, "tremors!"
kaasinees
not rated yet Feb 08, 2012
or use them as a source of efficient food.
C_elegans
not rated yet Feb 08, 2012
This isn't suprising, worms are pretty fast on a solid surface, such as an agar plate. Worms thrash in fluids, it is much much slower than a worm moving on a solid surface. In this experiment solids are supplied to a fluid medium, and their velocity increases as they approach their maximum speed. Which is the speed that they move across a solid surface. Catchy headline though.

More news stories

Chimpanzees prefer firm, stable beds

Chimpanzees may select a certain type of wood, Ugandan Ironwood, over other options for its firm, stable, and resilient properties to make their bed, according to a study published April 16, 2014 in the open-access ...

For cells, internal stress leads to unique shapes

From far away, the top of a leaf looks like one seamless surface; however, up close, that smooth exterior is actually made up of a patchwork of cells in a variety of shapes and sizes. Interested in how these ...

Down's chromosome cause genome-wide disruption

The extra copy of Chromosome 21 that causes Down's syndrome throws a spanner into the workings of all the other chromosomes as well, said a study published Wednesday that surprised its authors.