High-speed images capture archer fish’s rocket-like launch
The archer fish is arguably the ninja of the aquatic world, known for its stealth-like, arrow-straight aim while shooting down unsuspecting prey. Once the fish has sighted its target, it can spit jets of water to dislodge insects from overhanging leaves, making them topple into the water. But once an insect is shot down, it becomes fair game for any passing predator, and the archer fish is not necessarily the first to catch the fallen quarry. That’s when the fish’s other equally impressive, though less-studied, prey-capture strategy can be an advantage. In addition to spit-shooting, an archer fish can launch itself from a near standstill, out of the water to a height of more than two times its body length. In this way, it can catch an insect in midair, ensuring that no other competitor steals its prey. Now MIT engineers have detailed the hydrodynamics of the archer fish’s rocket-like jumping behavior...