How Did the Archer Fish Learn Physics?

A little fish that shoots down bugs out of the air learned some tricks of optics and propulsion that impress scientists.

A video clip on New Scientist shows a fish sneaking up to the air-water interface, pausing, then spitting a bug out of a bush with uncanny accuracy.  “Archer fish are expert marskmen,” the article begins.  “Now it seems they fine-tune their jets to pack an extra punch.”

The article, and similar write-ups on PhysOrg, Science Daily, Nature, the BBC News and Live Science, speaks with admiration about how this little fish overcomes numerous problems of physics to do this.  Because of the air-water interface, the fish has to be able to calculate the angle correctly, taking into account the index of refraction.  The fish also has to accurately calculate the distance to the bug from beneath the water.  And now, scientists at the University of Bayreuth have learned, the fish can pack that “extra punch” by reinforcing the first spit with a rapid series of follow-up spits too quick to see except with a high-speed camera.

The BBC article quotes one of the surprised scientists coming up with a “crazy idea.”  He wonders if these fish, with their “dynamic jet control,” are showing signs of cognitive evolution:

Prof Schuster believes that their spitting accuracy may have evolved in a similar way to human throwing, which some theorists argue sparked an accompanying expansion of our cognitive abilities. …

“People have calculated that to double [throwing] range requires roughly an 8-fold increase in the number of neurons involved in throwing,” Prof Schuster said.

So are these fish evolving into the cleverest animals under water?

“I don’t think they will develop into humans. [But] they have many strange abilities that you wouldn’t expect from fish.

“Maybe we can show by looking more closely at the brain, that shooting might have played a similar, prominent role in driving these abilities, as it’s thought that throwing played in human evolution.

“That’s just a crazy idea of mine.”

None of the other articles mentioned evolution, except for a brief summary of the above by Nature: “This ability is analogous to throwing in humans and could similarly have contributed to the evolution of cognitive skills in the fish, the authors say.”

So far, no Archer Fish Philosophy Clubs have been observed yet.

It’s weird how we have to classify many articles as both “amazing” and “dumb”.  They’re usually accompanied by apparitions of Charlie’s Ghost.