December 14, 2013 — The minnows known as golden shiners put on displays of synchronized swimming that could impress even the toughest Olympic judge. The ability of shiners and other fishes to change direction in harmony has long intrigued scientists, who have developed several ways of describing in mathematical terms how schooling works. But those approaches tend to be simplifications that do not take into account all the real-time sensory information available to the fish.
To get a better idea of what the fish were actually doing, Princeton University biologist Iain Couzin and his colleagues devised a way to make golden shiners move en masse and on cue. The researchers taught a few fish to swim toward a green light to find food and then placed those fish in a larger school. When the light went on, the trained fish broke toward it, triggering a cascade of responses as the rest of the school fell in behind the leaders.
Couzin and his colleagues filmed the action with high-speed video that allowed the researchers to map each fish’s visual field using the location and position of its head. The researchers reported in Current Biology that each fish based its decisions on where to go not on the behavior of its nearest neighbors, as is often assumed, but on a synthesis of where all the fish in its field of view were headed.
Read the full story from Scientific American at Salon