lateral line

Brook trout and its prominent lateral line

The brook trout, Salvelinus fontinalis, has a prominent lateral line.

The lateral line is a system of sensory cells embedded in pits or canals along the side of the body in fish and tailed amphibians. These organs probably detect the low-frequency vibrations in water which come from the movement of prey and shoaling companions. It is also possible that movements set up by the animal itself and reflected off distant objects may be detected in a form of echo-location.