Due to their body shape, seahorses are very slow swimmers. Most fish are far more efficient in their movement. But Brad Gremmell, a marine biologist at the University of Texas, thinks that he’s found an evolutionary advantage in their body shape.
The primary prey of seahorses are copepods—tiny marine crustaceans. Mr. Gremmell says that these creatures are incredibly fast:
"They're very, very sensitive to disturbances in the water, such as those created by approaching predators."
Once copepods detect these disturbances, they can swim distances of more than 500 times their body length per second. In comparison, "a cheetah probably only runs 30 body lengths per second," Gemmell said. If the average U.S. adult male traveled 500 body lengths per second, based on their height, they would move nearly 2,000 mph (3,200 km/h).
Nonetheless, slow seahorses can catch copepods. Because of their lean, narrow snouts, seahorses can approach copepods by stealth. They can get within biting distance without disturbing the water and alerting the copepods.
As in Dune, the slow blade penetrates the shield.
-via Glenn Reynolds