Sensory ecology of the fish lateral‐line system: Morphological and physiological adaptations for the perception of hydrodynamic stimuli

Abstract

Fishes are able to detect and perceive the hydrodynamic and physical environment they inhabit and process this sensory information to guide the resultant behaviour through their mechanosensory lateral‐line system. This sensory system consists of up to several thousand neuromasts distributed across the entire body of the animal. Using the lateral‐line system, fishes perceive water movements of both biotic and abiotic origin. The anatomy of the lateral‐line system varies greatly between and within species. It is still a matter of debate as to how different lateral‐line anatomies reflect adaptations to the hydrodynamic conditions to which fishes are exposed. While there are many accounts of lateral‐line system adaptations for the detection of hydrodynamic signals in distinct behavioural contexts and environments for specific fish species, there is only limited knowledge on how the environment influences intra and interspecific variations in lateral‐line morphology. Fishes live in a wide range of habitats with highly diverse hydrodynamic conditions, from pools and lakes and slowly moving deep‐sea currents to turbulent and fast running rivers and rough coastal surf regions. Perhaps surprisingly, detailed characterisations of the hydrodynamic properties of natural water bodies are rare. In particular, little is known about the spatio‐temporal patterns of the small‐scale water motions that are most relevant for many fish behaviours, making it difficult to relate environmental stimuli to sensory system morphology and function. Humans use bodies of water extensively for recreational, industrial and domestic purposes and in doing so often alter the aquatic environment, such as through the release of toxicants, the blocking of rivers by dams and acoustic noise emerging from boats and construction sites. Although the effects of anthropogenic interferences are often not well understood or quantified, it seems obvious that they change not only water quality and appearance but also, they alter hydrodynamic conditions and thus the types of hydrodynamic stimuli acting on fishes. To date, little is known about how anthropogenic influences on the aquatic environment affect the morphology and function of sensory systems in general and the lateral‐line system in particular. This review starts out by briefly describing naturally occurring hydrodynamic stimuli and the morphology and neurobiology of the fish lateral‐line system. In the main part, adaptations of the fish lateral‐line system for the detection and analysis of water movements during various behaviours are presented. Finally, anthropogenic influences on the aquatic environment and potential effects on the fish lateral‐line system are discussed.

Multimodal mechanosensing enables treefrog embryos to escape egg-predators

“…The mechanosensory lateral line system is found in all fishes and aquatic life stages of amphibians and serves to detect movement, vibrations, and pressure gradients in the surrounding water. It is comprised of mechanoreceptive neuromast sensory organs with hair cells that are sensitive to local water displacements (Lannoo, 1999) and are similar in morphology and function to hair cells in the auditory and vestibular system of vertebrates (Mogdans, 2019;Roberts et al, 1988). The lateral line system and vestibular system are responsive to many of the same stimulus fields (Braun and Coombs, 2000) and the hair cells of the lateral line and inner ear even have comparable thresholds of pressure detection (Van Netten, 2006).…”

Characterization of mouse Bmp5 regulatory injury element in zebrafish wound models

“…5 To test responses to chemical injury rather than tail resection, we also examined IRE responses after lateral line injury. The lateral line of zebrafish is a mechanosensory organ used by fish to sense water movements (Mogdans 2019). The sensory apparatus is made up of neuromasts, cone shaped structures dispersed along the lateral flank of the fish that contain innervated sensory hair cells surrounded by rings of support cells and mantle cells (Webb 2011).…”

Multimodal mechanosensing enables treefrog embryos to escape egg-predators

“…The mechanosensory lateral line system is found in all fishes and aquatic life stages of amphibians and serves to detect movement, vibrations, and pressure gradients in the surrounding water. It is comprised of mechanoreceptive neuromast sensory organs with hair cells that are sensitive to local water displacements (Lannoo, 1999) and are similar in morphology and function to hair cells in the auditory and vestibular system of vertebrates (Mogdans, 2019;Roberts et al, 1988). The lateral line system and vestibular system are responsive to many of the same stimulus fields (Braun and Coombs, 2000) and the hair cells of the lateral line and inner ear even have comparable thresholds of pressure detection (Van Netten, 2006).…”