Fastest Spring in Nature: Vorticella! Don’t blink now , but what you see as a graceful drifting up of the champagne-glass like body actually comes after an incredibly rapid contraction (~5 milliseconds) of the stalk. For its size, Vorticella convallaria is one of the fastest moving organisms on the planet.
What is this? Vorticella is a protozoan that attaches to solid objects (here, a layer of algae) through extremely strong natural adhesives. The 40 μm body is held up by a 150 μm long stalk.
How do they do this? Inside the stalk is a contractile spring, called the spasmoneme, which rapidly winds helically in response to binding calcium. The calcium signal is propagated down the stalk as a wave, after release from the body. This is similar to a muscle contraction, except that Vorticella is 10 times faster.
How fast is it? Contraction speed is estimated at 10 cm s−1. Expressed in units of lengths per second (Ls−1) (standard for muscle contraction), this works out to around 200 Ls−1. This speed is an order of magnitude faster than the fastest muscles, which contract at around 20 Ls−1. The tensile force is up to 500 nNewton. Young’s modulus of the stalk is around 1 kPa.
Why do they do this? Contraction is a defense mechanism to protect Vorticella from environmental hazards such as turbulent water.
♫ Music for Science ♫: Konstantin Makov suggests listening to The Beatles – Maxwell’s Silver Hammer (2009 Stereo Remaster) while you marvel at Nature’s fastest spring. Is Maxwell pounding on the little heads with an invisible hammer? Thank you, Konstantin, for being funny and clever as always.
Fastest Gif-er on G+: Thank you Kevin Staff for being tolerant of my requests and obliging me for #ScienceSunday once again!
Read more: Don’t blink: observing the ultra-fast contraction of spasmonemes. Marshall WF. http://www.ncbi.nlm.nih.gov/pubmed/17933874