One of eight distinct lateral lines in the 4-day larva consisting of 2 neuromast. One neuromast is positioned at the front edge of the jaw the second posteriorly on the mandible. A sensory system on the surface of the fish, consisting of small sensory patches (neuromasts) distributed in discrete lines over the body surface. The lateral line system is stimulated by local water displacements and vibrations, and detects propulsion of the fish through the water, as well as facilitating shoaling, prey capture, and predator and obstacle avoidance. (See Anatomical Atlas entry for lateral line by T. Whitfield.). [ http://zfin.org/curator ]