The mechanics of the clupeid acoustico-lateralis system: frequency responses

1979 ◽  
Vol 59 (1) ◽  
pp. 27-47 ◽  
Author(s):  
E. J. Denton ◽  
J. A. B. Gray ◽  
J. H. S. Blaxter
Keyword(s):  
Lateral Line ◽  
Clupea Harengus ◽  
Sprattus Sprattus ◽  
Lateral Recess ◽  
Mechanical Responses ◽  
Frequency Responses ◽  
Pressure Changes ◽  
System Frequency ◽  
Oscillatory Pressure

The mechanical responses of several structures in the auditory and lateral-line systems of the sprat Sprattus sprattus(L.) and the herringClupea harengus L. to oscillatory pressure changes have been observed over a range of frequencies from 0·014 t0 2600 Hz. The pressures required to give constant responses of the bulla membrane, and the lateral recess membrane varied relatively little between 0·014 and 1000 Hz; above 1000 Hz the sensitivity fell quickly as frequency increased.

Stimulation of the acoustico-lateralis system of clupeid fish by external sources and their own movements

1993 ◽  
Vol 341 (1296) ◽  
pp. 113-127 ◽  
Keyword(s):  
Lateral Line ◽  
External Source ◽  
Clupea Harengus ◽  
Pressure Gradients ◽  
Surrounding Water ◽  
Low Frequencies ◽  
Lateral Recess ◽  
Lateral Lines ◽  
External Sources ◽  
Net Pressure

1. The receptor organs of the acoustico-lateralis system in fish respond in various ways to pressures and pressure gradients and provide the fish with information about external sources of vibration. 2. A fish’s movements will set up pressures and pressure gradients and this poses three questions, (i) Can a fish obtain useful information from self-generated pressures and pressure gradients? (ii) To what extent do self-generated pressures mask signals from external sources? (iii) Can interactions between external and self-generated pressures and gradients in the acoustico-lateralis system give patterns of activity from the receptor organs which have special significance? 3. In herring ( Clupea harengus L. ) and sprat ( Spratus sprattus (L.)) measurements have been made of dimensions of various parts of the acoustico-lateralis system particularly of the subcerebral perilymph canal which crosses the head between the lateral lines. 4. Self-generated pressures produced by lateral movements of the head are antisymmetric, i.e. equal and opposite in sign on the left and right sides of the head. They oppose the accelerations of the head that produce them. In contrast, external sources give pressures that are largely symmetric. Any pressure gradients they give will accelerate the fish and the surrounding water together and any net pressure gradients will be small and so will any flows through the subcerebral perilymph canal. 5. Flows of liquid between the lateral lines across the lateral-recess membranes have been measured at various frequencies for pressure gradients applied across the head. Between 5 and 200 Hz the velocity of flow per unit pressure does not vary by more than than a factor of 2. At low frequencies the absolute values of flow are very much larger (more than 50 times) than those found for equally large symmetrically applied pressures (as from an external source) due to flow into the elastic gas containing bullae. 6. It is calculated that a net pressure difference (at optimum frequency) across the head of only 0.008 Pa will reach threshold for the lateral line neuromast nearest the lateral recess and one of 0.02 Pa for that under the eye. The responses of these neuromasts are expected to saturate and provide little information when the pressure differences across the head exceed 6 to 18 Pa. The pressures given by the swimming fish are discussed in the light of a theory advanced by Lighthill in the paper that follows this paper. With such antisymmetric pressures the direction of flow in the lateral-line canals will be towards the lateral recess on one side of the fish and away on the other and so differ from the situation found with an external source when flow at any instant will be either towards or away from the lateral recess on both sides of the head. 7. Antisymmetric pressures can produce large flows past the utricular maculae. However, at low frequencies flows across the maculae, on which their stimulation depends, will be small. We do not know the direction of these latter flows though they will be in opposite sense on the two sides of the head, again unlike the situation with an external source. 8. Calculations of impedances below 30 Hz show that the observed flows across the head are consistent with the dimensions and properties of the known structures. 9. There are major and systematic differences in the patterns of receptor organ stimulation between those expected from external sources and from a fish’s own movements. 10. Experiments on the red mullet ( Mullus surmuletus L.) showed that it too has a transverse channel connecting the right and left lateral-line systems. At low frequencies its properties resemble those of the subcerebral perilymph canal of the clupeid.

Structure and development of the free neuromasts and lateral line system of the herring

1983 ◽  
Vol 63 (2) ◽  
pp. 247-260 ◽  
Author(s):  
J. H. S. Blaxter ◽  
J. A. B. Gray ◽  
A. C. G. Best
Keyword(s):  
Lateral Line ◽  
Hair Cells ◽  
Phase Contrast ◽  
Vital Staining ◽  
Clupea Harengus ◽  
Lateral Line System ◽  
Line System ◽  
Sprattus Sprattus ◽  
Anterior Trunk ◽  
Scanning Electron

Vital staining with Janus Green, phase contrast and scanning electron microscopy were used to map the distribution of free neuromast organs from first hatching, 10 mm long larvae to 100 mm long juveniles of herring (Clupea harengus L.), with some further observations on juvenile sprat (Sprattus sprattus (L.)). Neuromasts are sparsely distributed on the head and trunk at hatching but soon proliferate on the trunk where, by a length of 13–15 mm, they occur one to every segment. Near metamorphosis there are at least three rows of neuromasts on the anterior trunk region, 6–9 single neuromasts on the caudal fin and as many as 50 on the head. The scales develop at about 40–50 mm and the neuromasts are then found singly or in groups of 2 or 3 on the surface of the scales of the anterior trunk.The lateral line develops at 22–24 mm and appears to incorporate existing free neuromasts on the side of the head. Unlike the cupulae of the free neuromasts, which are cylindrical, the lateral-line cupulae are thin erect plates lying along the axis of the canals. They are probably continually growing and being shed, followed by renewed growth.All neuromasts contain hair cells of opposing polarities; most free neuromasts are arranged with these polarities arranged fore-and-aft, but a few are dorsoventral.

Trophic decoupling of mesozooplankton production and the pelagic planktivores sprat Sprattus sprattus and herring Clupea harengus in the Central Baltic Sea

2018 ◽  
Vol 592 ◽  
pp. 181-196 ◽  
Author(s):  
M Bernreuther ◽  
J Peters ◽  
C Möllmann ◽  
J Renz ◽  
J Dutz ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Clupea Harengus ◽  
Sprattus Sprattus

Application of an Advanced Frequency Domain Identification Method for Modelling of Flexible-Link Manipulators

2003 ◽  
Author(s):  
G. M. Y. Lai ◽  
K. Ziaei ◽  
D. W. L. Wang ◽  
G. R. Heppler
Keyword(s):  
System Identification ◽  
Transfer Function ◽  
Frequency Domain ◽  
Contact Force ◽  
Strain Gauges ◽  
Flexible Link ◽  
Domain Identification ◽  
Frequency Responses ◽  
System Frequency ◽  
Identification Tool

This paper investigates the Comprehensive Identification from FrEquency Responses (CIFER) technique as a system identification tool for the Single Flexible Link (SFL) manipulator system. Frequency responses are identified for both the constrained and unconstrained motions. For the constrained case, two sets of frequency responses are identified based on actual contact force and an approximated contact force obtained through strain gauges readings. Identification results from CIFER® are compared to those from the Empirical Transfer Function Estimate (ETFE).

On The Fine Structure of Lateral-Line Canal Organs of the Herring (Clupea Harengus)

1985 ◽  
Vol 65 (3) ◽  
pp. 751-758 ◽  
Author(s):  
J. Mørup Jørgensen
Keyword(s):  
Lateral Line ◽  
Moving Objects ◽  
Sea Water ◽  
Clupea Harengus ◽  
Lateral Line System ◽  
Pressure Waves ◽  
Canal System ◽  
Line System ◽  
Lateral Line Canal ◽  
Lower Vertebrates

The lateral-line system of water-living lower vertebrates is provided with mechanoreceptors enabling the animals to detect water displacements, either caused by moving objects such as prey, predators or neighbours in a school or by deformations of pressure waves from the swimming animal caused by other objects. Cyclostomes, some fish and water–living amphibians have their lateral-line organs situated superficially in the epidermis as free neuromasts, while most fish besides these neuromasts possess a canal system in the dermis. Ordinarily the lateral line canal system consists of a few canals on the sides of the head and a trunk canal. In herring, however, the canal system is confined to the head and opercule. It forms a very richly branched system with numerous pores which connect the canal fluid with the surrounding sea water.

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