How does the lateral line system help trout sense nearby moving objects?

The lateral line system in trout acts as a remote sense of touch, allowing the fish to detect and localize nearby moving objects, such as other fish. This system functions through a series of specialized mechanoreceptors called neuromasts.12

In trout, these neuromasts are embedded beneath the scales along the body's midline and within a network of sensory canals on the head, connecting to the surface through pores. Each neuromast contains sensory cells with tiny, hairlike projections (cilia) that extend into a jellylike structure known as the cupula. When an object moves nearby, it creates water displacements or pressure changes that bend the cupula, deforming the sensory hairs. This mechanical stimulation triggers neural impulses that allow the trout to determine the direction and rate of the water movement, effectively sensing the presence of predators, prey, or other organisms before physical contact occurs.123