Innervation of the lateral line system in Rhyacichthys aspro: the origin of superficial neuromast rows in gobioids (Perciformes: Rhyacichthyidae)

ABSTRACTMembers of the family Gobiidae have an unusual lateral line morphology in which some of the lateral line canal segments do not develop or enclose. This loss of lateral line canal segments is frequently accompanied by proliferation of superficial neuromasts. Although the proliferation of superficial neuromasts forms intricate patterns that have been used as a taxonomic tool to identify individual gobiid species, there has never been a detailed study that has documented the development of the lateral line system in gobies. The Round Goby, Neogobius melanostomus, is the focus of this study because the absence of the lateral line canal segments below the eye are accompanied by numerous transverse rows of superficial neuromasts. Our results suggest that the origin of some of these superficial neuromast lines could be the result of single presumptive canal neuromasts that have proliferated after canal enclosure is arrested. Many of the intricate patterns of neuromasts observed in gobiids develop from a simplified pattern of neuromast that is very similar among different species of gobies. The proliferation of superficial neuromasts has evolved several times in fish families such as the tetras, gobies, and sculpins, and may provide an adaptive advantage to ‘tune’ the lateral line system for different environments and prey types.SIGNIFICANCE STATEMENTUnderstanding the development of different lateral line morphologies can provide insights into how these morphologies have convergently evolved in many fish taxa. This is the first study to document the progression of the development of the reduced lateral line morphology. This study shows evidence that the developmental origins of orthogonal lines of superficial neuromasts posterior to the eye are not neomorphic lines, but in fact arise from precursor neuromasts that seem to be analogous to presumptive canal neuromasts.

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Lateral line system

AccessScience ◽

10.1036/1097-8542.757316 ◽

2015 ◽

Keyword(s):

Lateral Line ◽

Lateral Line System ◽

Line System

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The lateral line system and its innervation in the Japanese eel Anguilla japonica (Teleostei: Elopomorpha: Anguillidae)

Journal of Morphology ◽

10.1002/jmor.21353 ◽

2021 ◽

Author(s):

Masanori Nakae ◽

Mari Kuroki ◽

Mao Sato ◽

Kunio Sasaki

Keyword(s):

Lateral Line ◽

Anguilla Japonica ◽

Japanese Eel ◽

Lateral Line System ◽

Line System

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Frequency response properties of primary afferent neurons in the posterior lateral line system of larval zebrafish

Journal of Neurophysiology ◽

10.1152/jn.00414.2014 ◽

2015 ◽

Vol 113 (2) ◽

pp. 657-668 ◽

Cited By ~ 9

Author(s):

Rafael Levi ◽

Otar Akanyeti ◽

Aleksander Ballo ◽

James C. Liao

Keyword(s):

Lateral Line ◽

Sine Wave ◽

Afferent Neuron ◽

Lateral Line System ◽

Afferent Neurons ◽

Primary Afferent Neurons ◽

Primary Afferent ◽

Line System ◽

Response Properties ◽

Larval Zebrafish

The ability of fishes to detect water flow with the neuromasts of their lateral line system depends on the physiology of afferent neurons as well as the hydrodynamic environment. Using larval zebrafish ( Danio rerio), we measured the basic response properties of primary afferent neurons to mechanical deflections of individual superficial neuromasts. We used two types of stimulation protocols. First, we used sine wave stimulation to characterize the response properties of the afferent neurons. The average frequency-response curve was flat across stimulation frequencies between 0 and 100 Hz, matching the filtering properties of a displacement detector. Spike rate increased asymptotically with frequency, and phase locking was maximal between 10 and 60 Hz. Second, we used pulse train stimulation to analyze the maximum spike rate capabilities. We found that afferent neurons could generate up to 80 spikes/s and could follow a pulse train stimulation rate of up to 40 pulses/s in a reliable and precise manner. Both sine wave and pulse stimulation protocols indicate that an afferent neuron can maintain their evoked activity for longer durations at low stimulation frequencies than at high frequencies. We found one type of afferent neuron based on spontaneous activity patterns and discovered a correlation between the level of spontaneous and evoked activity. Overall, our results establish the baseline response properties of lateral line primary afferent neurons in larval zebrafish, which is a crucial step in understanding how vertebrate mechanoreceptive systems sense and subsequently process information from the environment.

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Diversity and sexual dimorphism in the head lateral line system in North Sea populations of threespine sticklebacks, Gasterosteus aculeatus (Teleostei: Gasterosteidae)

Zoomorphology ◽

10.1007/s00435-020-00513-1 ◽

2020 ◽

Author(s):

Harald Ahnelt ◽

David Ramler ◽

Maria Ø. Madsen ◽

Lasse F. Jensen ◽

Sonja Windhager

Keyword(s):

Sexual Dimorphism ◽

North Sea ◽

Lateral Line ◽

Gasterosteus Aculeatus ◽

Sensory System ◽

Threespine Stickleback ◽

Lateral Line System ◽

Line System ◽

Marine Population ◽

Threespine Sticklebacks

AbstractThe mechanosensory lateral line of fishes is a flow sensing system and supports a number of behaviors, e.g. prey detection, schooling or position holding in water currents. Differences in the neuromast pattern of this sensory system reflect adaptation to divergent ecological constraints. The threespine stickleback, Gasterosteus aculeatus, is known for its ecological plasticity resulting in three major ecotypes, a marine type, a migrating anadromous type and a resident freshwater type. We provide the first comparative study of the pattern of the head lateral line system of North Sea populations representing these three ecotypes including a brackish spawning population. We found no distinct difference in the pattern of the head lateral line system between the three ecotypes but significant differences in neuromast numbers. The anadromous and the brackish populations had distinctly less neuromasts than their freshwater and marine conspecifics. This difference in neuromast number between marine and anadromous threespine stickleback points to differences in swimming behavior. We also found sexual dimorphism in neuromast number with males having more neuromasts than females in the anadromous, brackish and the freshwater populations. But no such dimorphism occurred in the marine population. Our results suggest that the head lateral line of the three ecotypes is under divergent hydrodynamic constraints. Additionally, sexual dimorphism points to divergent niche partitioning of males and females in the anadromous and freshwater but not in the marine populations. Our findings imply careful sampling as an important prerequisite to discern especially between anadromous and marine threespine sticklebacks.

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