Underwater Assassin

The ingenuity of the archerfish has been observed for a long time. This small fish, usually no more than a few inches long, has two fine-tuned traits: great eyesight and incredible control of its spitting muscles. With this skill set it can shoot down flying insects by spitting a jet of water up to at least six feet. Then it eats.

“We knew about this behavior, the spitting mechanism,” Matthew Girard, an ichthyologist at the Smithsonian Institution, tells NBC News. “It was a question of, how did that evolve? What happened that led to something so incredible?”
Girard led a new study, published in the journal Integrative Organismal Biology, that could explain how these underwater Annie Oakleys evolved. His team gathered information on nine different archerfish species from around the world, and compared their morphology to a closely related species, the beach salmon, which has very similar bones and tissue structures. The salmon doesn’t shoot down its prey, though. Instead it uses its not-quite-unique internal structure to chew up the tough armor on the crustaceans it feeds on, and then to eject the inedible parts.
The archerfish likely started out the same way, but the relentless mechanism of natural selection over time led to the fish’s particular, peculiar skill set.
The Sea Life London Aquarium shows off the sharpshooting prowess with a target above their archerfish pool, and their residents rarely miss. The US Navy named a WWII submarine USS Archerfish, whose signature achievement was sinking a Japanese aircraft carrier, the largest warship ever sunk by a sub.
Witness the carnage here: youtube.com/watch?v=S4G_MeUUZlI.

Photo credit: Paulo Oliveira / Alamy Stock Photo