New model explains how these swimmers use their lateral lines to read wakes
Special sensory cells in fish respond reliably to swirly wakes, allowing fish to hunt down prey or join a friendly school by reading the watery traces, a paper to appear in Physical Review Letters suggests.
As fish, and other objects, move through water, they leave behind long-lasting vortices, or wakes, says study coauthor Jacob Engelmann of Bonn University in Germany, like the residual swirls left by a canoe paddle in a lake. “You can tell where the fish was, even minutes after the fish is gone,” he says. Researchers knew that fish, which rely heavily on senses other than vision, detected such footprints, but the details of how were unclear.
Fish feel pressure changes in the water around them with a system called the lateral line, which sits just below the scales. A typical fish has a stripe of sensory units called neuromasts down each side and various rows of the units on its head. Each sensor is made up of hair cells, similar to the ones