Archerfish tune their shots to universal properties of prey adhesion

October 9, 2006

Archerfish exhibit the remarkable ability to hunt for insects and other small terrestrial animals by firing precisely aimed streams of water that knock prey onto the water's surface. These water shots were once thought to be all-or-none in quality, but researchers have now discovered new levels of sophistication in the archerfish's hunting strategy that shed light on how this impressive predatory behavior has evolved.

The findings are reported by Thomas Schlegel, Christine Schmid, and Stefan Schuster of the Universität Erlangen-Nürnberg in Erlangen, Germany, and appear in the October 10th issue of the journal Current Biology, published by Cell Press.

By employing high-resolution imaging of water streams fired during archerfish hunting, researchers have discovered that archerfish automatically tune the force they use to dislodge prey according to prey size, and that this strategy appears to be resistant to alteration by experience: It occurs even when the fish have been placed for two years in an environment that has been manipulated to make such tuning unnecessary for successful hunting.

The findings suggest that the tuning aspect of the archerfish's hunting strategy is not as plastic in response to learning as might have been thought. Instead, the strategy may reflect the evolution of archerfish behavior in accordance with a recently discovered scaling law: Among animals such as flies and lizards, an animal's adhesive force--its natural tendency to stick to a surface--is closely proportional to the animal's size.

The researchers showed that for any given size of prey, the archerfish tune their attacks such that prey are hit with about ten times the force that adhesive organs of animals of that size could sustain.

The new work also revealed that the archerfish's hunting technique is metabolically costly and that the fish tune the force of their water shots by adjusting the mass of water in a shot, rather than altering the initial release pressure and speed of the shot. This turns out to be the most efficient way of adjusting force--by doubling the mass of water shot, the fish double the force that is applied to prey in a way that only doubles the energetic cost of the shot; doubling speed of the shot would require quadrupled energetic cost.

Citation: Schlegel et al.: "Archerfish shots are evolutionarily matched to prey adhesion." Publishing in Current Biology Vol 16 No 19, R836-7. DOI 10.1016/j.cub.2006.08.082

Source: Cell Press

Explore further: Archerfish target shoot with 'skillfully thrown' water

Related Stories

Archerfish target shoot with 'skillfully thrown' water

September 4, 2014

Archerfish hunt by shooting jets of water at unsuspecting insects, spiders, or even small lizards on leaves or twigs above, knocking them into the water below before gobbling them up. Now, a study in the Cell Press journal ...

Archerfish get an eye test (w/ video)

March 21, 2013

(Phys.org) —A modified version of an eye test used to assess visual acuity in the military has been given to archerfish by scientists to help explain how these remarkable fish are able to accurately spit down tiny insects ...

Scientists discover fish using tools may be wide spread

December 1, 2011

Dr. Culum Brown, who recently made headlines publishing the first photographic evidence of a tusk fish using tools to smash open shells says, “There is an increasing body of evidence that suggests that fish have been ...

Recommended for you

Researchers design first artificial ribosome

July 29, 2015

Researchers at the University of Illinois at Chicago and Northwestern University have engineered a tethered ribosome that works nearly as well as the authentic cellular component, or organelle, that produces all the proteins ...

Meet the high-performance single-molecule diode

July 29, 2015

A team of researchers from Berkeley Lab and Columbia University has passed a major milestone in molecular electronics with the creation of the world's highest-performance single-molecule diode. Working at Berkeley Lab's Molecular ...

Researchers build bacteria's photosynthetic engine

July 29, 2015

Nearly all life on Earth depends on photosynthesis, the conversion of light energy into chemical energy. Oxygen-producing plants and cyanobacteria perfected this process 2.7 billion years ago. But the first photosynthetic ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.