What is the main purpose of the fish's lateral line system?

The lateral line system in fish serves primarily the purpose of orientation and movement detection within their aquatic environment. This sensory system comprises a series of specialized mechanoreceptors known as neuromasts, which are located in pits or canals along the sides of the fish. These neuromasts are highly sensitive to changes in water movement and pressure gradients, allowing fish to detect vibrations and currents in the water.

This capability is crucial for various aspects of a fish's life, including navigation, schooling behavior, and predator/prey detection. By responding to the flow of water caused by nearby objects or other fish, the lateral line system enables fish to maintain spatial awareness and adjust their movements accordingly to avoid obstacles or find food.

While the lateral line system does have a role in detecting pressure changes, the primary and most significant function is related to orientation and movement, making it vital for navigating the often complex underwater world.