Archerfish tune their shots to universal properties of prey adhesion

Oct 09, 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: Campaigners say protected birds in danger in Malta

add to favorites email to friend print save as pdf

Related Stories

Archerfish get an eye test (w/ video)

Mar 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 ...

Scientists discover fish using tools may be wide spread

Dec 01, 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 ...

Recommended for you

Genome yields insights into golden eagle vision, smell

2 hours ago

Purdue and West Virginia University researchers are the first to sequence the genome of the golden eagle, providing a bird's-eye view of eagle features that could lead to more effective conservation strategies.

Genetic code of the deadly tsetse fly unraveled

3 hours ago

Mining the genome of the disease-transmitting tsetse fly, researchers have revealed the genetic adaptions that allow it to have such unique biology and transmit disease to both humans and animals.

Ocean microbes display remarkable genetic diversity

3 hours ago

The smallest, most abundant marine microbe, Prochlorococcus, is a photosynthetic bacteria species essential to the marine ecosystem. An estimated billion billion billion of the single-cell creatures live i ...

Engineered E. coli produces high levels of D-ribose

4 hours ago

D-ribose is a commercially important sugar used as a sweetener, a nutritional supplement, and as a starting compound for synthesizing riboflavin and several antiviral drugs. Genetic engineering of Escherichia co ...

User comments : 0

More news stories

Genetic code of the deadly tsetse fly unraveled

Mining the genome of the disease-transmitting tsetse fly, researchers have revealed the genetic adaptions that allow it to have such unique biology and transmit disease to both humans and animals.

Ocean microbes display remarkable genetic diversity

The smallest, most abundant marine microbe, Prochlorococcus, is a photosynthetic bacteria species essential to the marine ecosystem. An estimated billion billion billion of the single-cell creatures live i ...

Cell resiliency surprises scientists

New research shows that cells are more resilient in taking care of their DNA than scientists originally thought. Even when missing critical components, cells can adapt and make copies of their DNA in an alternative ...

One in 13 US schoolkids takes psych meds

(HealthDay)—More than 7 percent of American schoolchildren are taking at least one medication for emotional or behavioral difficulties, a new government report shows.

FDA reconsiders behavior-modifying 'shock devices'

(HealthDay)—They're likened to a dog's "shock collar" by some and called a "life-saving treatment" by others. But the days of electro-shock devices as a tool for managing hard-to-control behavior in people ...

Computer program could help solve arson cases

Sifting through the chemical clues left behind by arson is delicate, time-consuming work, but University of Alberta researchers teaming with RCMP scientists in Canada, have found a way to speed the process.