Zebrafish Anatomical Dictionary

Structure description: lateral line

by Tanya Whitfield

Name: lateral line


Synonyms: None


lateral line diagram


live neuromasts

neuromast polarity

Description: 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. In the 4 day larva, there are eight distinct lateral lines (Raible and Kruse, 2000):

The ventral ramus of the posterior line is the familiar "trunk" or "midbody" line, formed by the posterior lateral line primordium, the migration of which is used as a staging tool (Kimmel et al., 1995).Each neuromast consists of a rosette of hair cells and supporting cells, with their apical surfaces protruding through a circular hole in the periderm. The kinocilia and stereocilia of the hair cells are encased in a gelatinous cupula, visible in the live larva with DIC optics. Neuromast hair cells are arranged in one of two opposing polarities; in the trunk, these correspond to the anteroposterior axis of the body. Hair cells are innervated by lateral line nerves; cell bodies of afferent neurons sit in cranial anterior and posterior lateral line ganglia. Three types of efferent neurons have been described that project axons into the posterior lateral line nerve (Metcalfe et al., 1985).



Parents (forms from): cranial placodal ectoderm (lateral line placodes), anterior and posterior to the otic vesicle. These give rise to migratory primordia, which travel beneath the periderm over the body surface, depositing clusters of cells as they go, which differentiate into the neuromasts.


Group (member of):



Comments: A study by (Collazo et al., 1994) suggests that there may be a small neural crest contribution to the lateral line.