Why do swordfish have long bills?

Answer: Slashing through fish schools

Slashing through fish schools ✓ — Correct! Swordfish slash their flat, sharp bills sideways through dense fish schools at high speed, stunning or killing multiple prey. The bill's shape reduces water resistance and allows rapid slicing movements. They then circle back to eat injured fish. It's a highly effective hunting weapon, not a spear!

Sensing electric fields — Wrong. While some sharks sense electricity, swordfish bills are mechanical weapons for slashing prey, not sensory organs.

Digging in ocean floor — Wrong. Swordfish are open-ocean predators hunting in water column, not bottom-feeders. The bill is for hunting fast-moving fish schools.