Swordfish: The 60-MPH Undersea Sprinter

A swordfish tagged off the coast of Florida in 2015 clocked a burst of sixty miles per hour-and that speed leaves bluefin tuna and even sharks behind. In the same year, researchers weighed the sword on deck and found its bill covered in micro-grooves, nearly invisible, but lined up parallel to water flow, cutting skin friction by nearly fifteen percent. The mystery went deeper: the swordfish's eyes are wired with specialized muscles that heat the eyeballs up to ten degrees Fahrenheit above the surrounding seawater, giving it perfect vision even at full tilt. Then, just below the skin, a thin layer of oil coats the head and sword at the exact moment of high-speed pursuit. The swordfish is the only fish with that oily slot, and no other animal operates at that temperature or speed in these depths. When the swordfish launches, it does all of this together to lunge for mackerel and squid, using its bill for both slicing and for speed. That forty-pound sword off Florida set the record with one hard strike, accelerating so quickly the tracking device registered g-forces usually seen in sports cars, and then vanished into the deep at sixty miles per hour.