The C-start escape response ofPolypterus senegalus: bilateral muscle activity and variation during stage 1 and 2

2002 ◽  
Vol 205 (17) ◽  
pp. 2591-2603 ◽  
Author(s):  
Eric D. Tytell ◽  
George V. Lauder
Keyword(s):  
Muscle Activity ◽  
Escape Response ◽  
High Speed ◽  
Wave Speed ◽  
Activity Patterns ◽  
Motor Pattern ◽  
The Body ◽  
Wide Range ◽  
Fast Start ◽  
Stage 1

SUMMARYThe fast-start escape response is the primary reflexive escape mechanism in a wide phylogenetic range of fishes. To add detail to previously reported novel muscle activity patterns during the escape response of the bichir, Polypterus, we analyzed escape kinematics and muscle activity patterns in Polypterus senegalus using high-speed video and electromyography (EMG). Five fish were filmed at 250 Hz while synchronously recording white muscle activity at five sites on both sides of the body simultaneously (10 sites in total). Body wave speed and center of mass velocity, acceleration and curvature were calculated from digitized outlines. Six EMG variables per channel were also measured to characterize the motor pattern. P. senegalus shows a wide range of activity patterns, from very strong responses, in which the head often touched the tail, to very weak responses. This variation in strength is significantly correlated with the stimulus and is mechanically driven by changes in stage 1 muscle activity duration. Besides these changes in duration, the stage 1 muscle activity is unusual because it has strong bilateral activity, although the observed contralateral activity is significantly weaker and shorter in duration than ipsilateral activity. Bilateral activity may stiffen the body, but it does so by a constant amount over the variation we observed; therefore, P. senegalus does not modulate fast-start wave speed by changing body stiffness. Escape responses almost always have stage 2 contralateral muscle activity, often only in the anterior third of the body. The magnitude of the stage 2 activity is the primary predictor of final escape velocity.

Mechanics of the fast-start: muscle function and the role of intramuscular pressure in the escape behavior of amia calva and polypterus palmas

1998 ◽  
Vol 201 (22) ◽  
pp. 3041-3055 ◽  
Author(s):  
MW Westneat ◽  
ME Hale ◽  
MJ Mchenry ◽  
JH Long
Keyword(s):  
Muscle Activity ◽  
Escape Response ◽  
Muscle Force ◽  
Escape Behavior ◽  
Pressure Change ◽  
The Body ◽  
Intramuscular Pressure ◽  
Fast Start ◽  
Amia Calva

The fast-start escape response is a rapid, powerful body motion used to generate high accelerations of the body in virtually all fishes. Although the neurobiology and behavior of the fast-start are often studied, the patterns of muscle activity and muscle force production during escape are less well understood. We studied the fast-starts of two basal actinopterygian fishes (Amia calva and Polypterus palmas) to investigate the functional morphology of the fast-start and the role of intramuscular pressure (IMP) in escape behavior. Our goals were to determine whether IMP increases during fast starts, to look for associations between muscle activity and elevated IMP, and to determine the functional role of IMP in the mechanics of the escape response. We simultaneously recorded the kinematics, muscle activity patterns and IMP of four A. calva and three P. palmas during the escape response. Both species generated high IMPs of up to 90 kPa (nearly 1 atmosphere) above ambient during the fast-start. The two species showed similar pressure magnitudes but had significantly different motor patterns and escape performance. Stage 1 of the fast-start was generated by simultaneous contraction of locomotor muscle on both sides of the body, although electromyogram amplitudes on the contralateral (convex) side of the fish were significantly lower than on the ipsilateral (concave) side. Simultaneous recordings of IMP, escape motion and muscle activity suggest that pressure change is caused by the contraction and radial swelling of cone-shaped myomeres. We develop a model of IMP production that incorporates myomere geometry, the concept of constant-volume muscular hydrostats, the relationship between fiber angle and muscle force, and the forces that muscle fibers produce. The timing profile of pressure change, behavior and muscle action indicates that elevated muscle pressure is a mechanism of stiffening the body and functions in force transmission during the escape response.

Environmental effects on undulatory locomotion in the American eel Anguilla rostrata: kinematics in water and on land

1998 ◽  
Vol 201 (7) ◽  
pp. 949-961 ◽  
Author(s):  
G. B. Gillis
Keyword(s):  
Muscle Activity ◽  
High Speed ◽  
Activity Patterns ◽  
The Body ◽  
Anguilla Rostrata ◽  
American Eel ◽  
Terrestrial Locomotion ◽  
Average Maximum ◽  
Undulatory Locomotion ◽  
Longitudinal Position

Historically, the study of swimming eels (genus Anguilla) has been integral to our understanding of the mechanics and muscle activity patterns used by fish to propel themselves in the aquatic environment. However, no quantitative kinematic analysis has been reported for these animals. Additionally, eels are known to make transient terrestrial excursions, and in the past it has been presumed (but never tested) that the patterns of undulatory movement used terrestrially are similar to those used during swimming. In this study, high-speed video was used to characterize the kinematic patterns of undulatory locomotion in water and on land in the American eel Anguilla rostrata. During swimming, eels show a nonlinear increase in the amplitude of lateral undulations along their bodies, reaching an average maximum of 0.08L, where L is total length, at the tip of the tail. However, in contrast to previous observations, the most anterior regions of their bodies do not undergo significant undulation. In addition, a temporal lag (typically 10–15 % of an undulatory cycle) exists between maximal flexion and displacement at any given longitudinal position. Swimming speed does not have a consistent effect on this lag or on the stride length (distance moved per tailbeat) of the animal. Speed does have subtle (although statistically insignificant) effects on the patterns of undulatory amplitude and intervertebral flexion along the body. On land, eels also use lateral undulations to propel themselves; however, their entire bodies are typically bent into waves, and the undulatory amplitude at all body positions is significantly greater than during swimming at equivalent speeds. The temporal lag between flexion and displacement seen during swimming is not present during terrestrial locomotion. While eels cannot move forwards as quickly on land as they do in water, they do increase locomotor speed with increasing tailbeat frequency. The clear kinematic distinctions present between aquatic and terrestrial locomotor sequences suggest that eels might be using different axial muscle activity patterns to locomote in the different environments.

S- and C-start escape responses of the muskellunge (Esox masquinongy) require alternative neuromotor mechanisms

2002 ◽  
Vol 205 (14) ◽  
pp. 2005-2016 ◽  
Author(s):  
Melina E. Hale
Keyword(s):  
Muscle Activity ◽  
Neural Circuit ◽  
Activity Patterns ◽  
Motor Pattern ◽  
Angular Acceleration ◽  
Neural Mechanism ◽  
The Body ◽  
Neural Basis ◽  
Esox Masquinongy ◽  
Undulatory Swimming

SUMMARYThe startle response is a model system for examining the neural basis of behavior because of its relatively simple neural circuit organization and kinematic pattern. In fishes, the two primary types of startle behavior differ in their initial movements. In the C-start type of startle, the fish bends into a C shape, while the S-start involves an S-shaped body bend. Although considerable research has focused on determining how the C-start is generated neurally, S-start neurobiology has not been examined. I quantify the kinematics and electromyographic patterns of the initial movements of the C-start and S-start behaviors of the muskellunge (Esox masquinongy)to test three hypotheses for how the S-start is generated. (i) The S-start is generated by the same motor neural circuit as the C-start, but passive bending of the tail causes the body to take on an S shape. (ii) The S-start is generated by the same motor neural circuit as undulatory swimming. (iii) The S-start is generated by an independent neural mechanism from that used either in the C-start or in undulatory swimming. Results from kinematics and muscle activity patterns support the third hypothesis. In the muskellunge, the S-start is a high-performance startle behavior with peak angular velocity and peak angular acceleration of its initial bending comparable with those of the C-start and higher than would be expected for undulatory swimming. The S-start motor pattern, however, is distinct from the C-start motor pattern in having simultaneous muscle activity anteriorly on one side of the body and posteriorly on the opposite side. In contrast, the C-start is characterized by simultaneous unilateral muscle activity along the full length of the body. Alternative models are proposed for S-start neural circuit organization involving reticulospinal and local control of muscle activity.

TAIL MUSCLE ACTIVITY PATTERNS IN WALKING AND FLYING PIGEONS (COLUMBA LIVIA)

1993 ◽  
Vol 176 (1) ◽  
pp. 55-76 ◽  
Author(s):  
S. M. Gatesy ◽  
K. P. Dial
Keyword(s):  
Muscle Activity ◽  
High Speed ◽  
Activity Patterns ◽  
Columba Livia ◽  
Trunk Muscles ◽  
Avian Evolution ◽  
Terrestrial Locomotion ◽  
Temporal Flexibility ◽  
High Speed Cinematography ◽  
Tail Muscle

The electrical activity of major caudal muscles of the pigeon (Columba livia) was recorded during five modes of aerial and terrestrial locomotion. Tail muscle electromyograms were correlated with movement using high-speed cinematography and compared to activity in selected muscles of the wings, legs and trunk. During walking, the pectoralis and most tail muscles are normally inactive, but levator muscle activity alternates with the striding legs. In flight, caudal muscles are phasically active with each wingbeat and undergo distinct changes in electromyographic pattern between liftoff, takeoff, slow level flapping and landing modes. The temporal flexibility of tail muscle activity differs significantly from the stereotypic timing of wing muscles in pigeons performing the same flight modes. These neural programs may represent different solutions to the control of flight surfaces in the rapidly oscillating wing and the relatively stationary caudal skeleton. Birds exhibit a novel alliance of tail and forelimb use during aerial locomotion. We suggest that there is evidence of anatomical and functional decoupling of the tail from adjacent hindlimb and trunk muscles during avian evolution to facilitate its specialization for rectricial control in flight.

Kinematics and efficiency of steady swimming in adult axolotls (Ambystoma mexicanum)

1997 ◽  
Vol 200 (13) ◽  
pp. 1863-1871 ◽  
Author(s):  
K D'Août ◽  
P Aerts
Keyword(s):  
Swimming Speed ◽  
High Speed ◽  
Natural Habitat ◽  
Total Body Length ◽  
Ambystoma Mexicanum ◽  
The Body ◽  
Entire Body ◽  
Amplitude Profile ◽  
Wide Range ◽  
Tail Tip

The kinematics of steady swimming at a wide range of velocities was analysed using high-speed video recordings (500 frames s-1) of eight individuals of Ambystoma mexicanum swimming through a tunnel containing stationary water. Animals in the observed size range (0.135­0.238 m total body length) prefer to swim at similar absolute speeds, irrespective of their body size. The swimming mechanism is of the anguilliform type. The measured kinematic variables ­ the speed, length, frequency and amplitude (along the entire body) of the propulsive wave ­ are more similar to those of anguilliform swimming fish than to those of tadpoles, in spite of common morphological features with the latter, such as limbs, external gills and a tapering tail. The swimming speed for a given animal size correlates linearly with the tailbeat frequency (r2=0.71), whereas the wavelength and tail-tip amplitude do not correlate with this variable. The shape of the amplitude profile along the body, however, is very variable between the different swimming bouts, even at similar speeds. It is suggested that, for a given frequency, the amplitude profile along the body is adjusted in a variable way to yield the resulting swimming speed rather than maintaining a fixed-amplitude profile. The swimming efficiency was estimated by calculating two kinematic variables (the stride length and the propeller efficiency) and by applying two hydrodynamic theories, the elongated-body theory and an extension of this theory accounting for the slope at the tail tip. The latter theory was found to be the most appropriate for the axolotl's swimming mode and yields a hydromechanical efficiency of 0.75±0.04 (mean ± s.d.), indicating that Ambystoma mexicanum swims less efficiently than do anuran tadpoles and most fishes. This can be understood given its natural habitat in vegetation at the bottom of lakes, which would favour manoeuvrability and fast escape.

The kinematics and performance of escape responses of the knifefish Xenomystus nigri

1993 ◽  
Vol 71 (1) ◽  
pp. 189-195 ◽  
Author(s):  
M. A. Kasapi ◽  
P. Domenici ◽  
R. W. Blake ◽  
D. Harper
Keyword(s):  
High Speed ◽  
Longitudinal Axis ◽  
The Body ◽  
Maximum Acceleration ◽  
Low Speed ◽  
Average Maximum ◽  
Morphological Specialization ◽  
Escape Responses ◽  
And Performance ◽  
Stage 1

The kinematics and performance of the escape responses of the knifefish Xenomystus nigri, a fish specialized for low-speed, undulatory median-fin propulsion, were recorded by means of high-speed cinematography. Two types of escape were observed, one involving the formation of a C-shape along the longitudinal axis of the fish (stage 1), followed by a slow recoil of the body (single bend); the other (double bend) involved stage 1 followed by a contralateral bend (stage 2). The pectoral fins were extended throughout escapes of both types. The average maximum acceleration for double bend escapes was 127.98 m∙s−2; acceleration was usually greatest in stage 1. In double bend escapes, turning angles for stages 1 and 2 were not correlated. Pitch and roll orientations change during escapes. In stage 1, the average roll and average pitch were linearly correlated, suggesting that roll was partly responsible for establishing pitch. Knifefish achieved high maximum acceleration relative to other fish. Therefore, performance was not compromised by morphological specialization for low-speed swimming; however, a negative correlation of pitch with acceleration in stage 1 suggested that escapes involve a trade-off between acceleration and confusing a predator by changing planar orientation.

Diverse anguilliform swimming kinematics in Pacific hagfish (Eptatretus stoutii) and Atlantic hagfish (Myxine glutinosa)

2015 ◽  
Vol 93 (3) ◽  
pp. 213-223 ◽  
Author(s):  
J.L. Lim ◽  
T.M. Winegard
Keyword(s):  
High Speed ◽  
Wave Speed ◽  
High Amplitude ◽  
The Body ◽  
Whole Body ◽  
Lateral Bending ◽  
Myxine Glutinosa ◽  
Eptatretus Stoutii ◽  
Swimming Kinematics ◽  
Broad Classification

Anguilliform mode swimmers pass waves of lateral bending down their elongate bodies to propel forward. Hagfishes (Myxinidae) are classified as anguilliform swimmers, but their unique habits and reduced morphology—including a flexible body lacking a vertebral column—have the potential to translate into unique swimming behaviour within this broad classification. Their roles as active scavengers and hunters can require considerable bouts of swimming, yet quantitative data on hagfish locomotion are limited. Here, we aim to provide a more complete mechanistic understanding of hagfish swimming by quantifying whole-body kinematics of steady swimming in Pacific hagfish (Eptatretus stoutii (Lockington, 1878)) and Atlantic hagfish (Myxine glutinosa L., 1758), species from the two main lineages of Myxinidae. We analyzed high-speed video of hagfishes swimming at voluntary swim speeds and found that both species swim using high-amplitude undulatory waves. Swim speed is generally frequency-modulated, but patterns in wave speed, wavelength, and amplitude along the body and across swim speeds are variable, implying versatile mechanisms for the control of swim speed in these highly flexible fishes. We propose mechanistic explanations for this kinematic variability and compare hagfish with other elongate swimmers, demonstrating that the hagfish’s rich locomotory repertoire adds variety to the already diverse set of locomotory kinematics found in anguilliform swimmers.

scholarly journals Escaping from multiple visual threats: Modulation of escape responses in Pacific staghorn sculpin (Leptocottus armatus).

2021 ◽  
Author(s):  
Hibiki Kimura ◽  
Tilo Pfalzgraff ◽  
Marie Levet ◽  
Yuuki Kawabata ◽  
John F Steffensen ◽  
...  
Keyword(s):  
Visual Stimulus ◽  
Escape Response ◽  
The Body ◽  
Body Motion ◽  
Time Interval ◽  
Time Intervals ◽  
Escape Responses ◽  
Leptocottus Armatus ◽  
Stage 1 ◽  
Staghorn Sculpin

Fish perform rapid escape responses to avoid sudden predatory attacks. During escape responses, fish bend their bodies into a C-shape and quickly turn away from the predator and accelerate. The escape trajectory is determined by the initial turn (Stage 1) and a contralateral bend (Stage 2). Previous studies have used a single threat or model predator as a stimulus. In nature, however, multiple predators may attack from different directions simultaneously or in close succession. It is unknown whether fish are able to change the course of their escape response when startled by multiple stimuli at various time intervals. Pacific staghorn sculpin (Leptocottus armatus) were startled with a left and right visual stimulus in close succession. By varying the timing of the second stimulus, we were able to determine when and how a second stimulus could affect the escape response direction. Four treatments were used: a single visual stimulus (control); or two stimuli coming from opposite sides separated by a 0 ms (simultaneous treatment); a 33 ms; or a 83 ms time interval. The 33 ms and 83 ms time intervals were chosen to occur shortly before and after a predicted 60 ms visual escape latency (i.e. during Stage 1). The 0 ms and 33 ms treatments influenced both the escape trajectory and the Stage 1 turning angle, compared to a single stimulation, whereas the 83 ms treatment had no effect on the escape response. We conclude that Pacific staghorn sculpin can modulate their escape response only between stimulation and the onset of the response, but that escape responses are ballistic after the body motion has started.

The Mechanism of Tongue Projection in Chameleons: I. Electromyographic Tests of Functional Hypotheses

1992 ◽  
Vol 168 (1) ◽  
pp. 1-21 ◽  
Author(s):  
PETER C. WAINWRIGHT ◽  
ALBERT F. BENNETT
Keyword(s):  
High Speed ◽  
Prey Capture ◽  
Activity Patterns ◽  
Motor Pattern ◽  
Companion Paper ◽  
Posterior Portion ◽  
Video Recordings ◽  
Single Burst ◽  
Intense Activity ◽  
Test Current

In this paper we document the activity of key muscles of the tongue, hyobranchial apparatus and head during prey capture in the lizard Chamaeleo jacksonii Boulenger and use these data to test current hypotheses of chameleon tongue function. Electromyographic recordings were made during 27 feedings from nine individuals and synchronized with high-speed video recordings (200 fields s−1), permitting an assessment of the activity of muscles relative to the onset of tongue projection, contact between tongue and prey, and tongue retraction. Four major results were obtained. (1) The hyoglossi muscles exhibit a single burst of activity that begins between 10 ms before and 20 ms after the onset of tongue projection and continues throughout the period of tongue retraction. (2) The accelerator muscle exhibits a biphasic activity pattern, with the first burst lasting about 185 ms and ending an average of 10.6 ms prior to the onset of projection. (3) The accelerator muscle shows regional variation in morphology that corresponds with variation in motor pattern. The anterior region of the muscle, unlike the posterior portion, exhibits only a single burst of activity that begins 2.5 ms after the onset of tongue projection and is thus not involved in launching the tongue. (4) The geniohyoidei, sternohyoidei, sternothyroidei, depressor mandibulae, adductor mandibulae and pterygoideus all exhibit activity patterns consistent with previously reported kinematic patterns and their proposed roles. The major implications of these results for models of the chameleon feeding mechanism are (1) that the hyoglossi do not act to hold the tongue on the entoglossal process during a loading period prior to tongue projection, and (2) that the presence of 185 ms of intense activity in the accelerator muscle prior to tongue projection suggests the presence of a preloading mechanism, the nature of which is the subject of the companion paper.

Prey Processing in Haemulid Fishes: Patterns of Variation in Pharyngeal Jaw Muscle Activity

1989 ◽  
Vol 141 (1) ◽  
pp. 359-375 ◽  
Author(s):  
PETER C. WAINWRIGHT
Keyword(s):  
Muscle Activity ◽  
Activity Patterns ◽  
Motor Pattern ◽  
Prey Type ◽  
Motor Patterns ◽  
Fish Family ◽  
Treatment Groups ◽  
Jaw Muscle ◽  
Species Effect ◽  
Pharyngeal Jaw

This study examines patterns of variation in 15 electromyographic (EMG) variables measured from recordings of pharyngeal jaw muscle activity during prey processing in four species of the perciform fish family Haemulidae. Two questions were of primary interest. (1) Are motor patterns conserved across the four species? (2) Do the fishes alter (modulate) muscle activity patterns when feeding on different prey types? The experimental design used allowed the partitioning of variance in EMG variables among species, among individuals within species, among days within individuals, among feedings within days, and among prey types. Only one variable exhibited a significant species effect, indicating that the four species used virtually the same motor pattern during prey processing. In response to three prey types differing in hardness, all four species demonstrated an ability to modulate several EMG variables that characterized the intensity of electrical activity. However, variables characterizing the relative timing of muscle activities were not influenced by prey type. A significant variance component was found among recording days and, together with the possibility of variation among experimental preparations, this raises questions about the extent of previously reported inter-individual variation in EMGs. These results support a growing data base on aquatic feeding in lower vertebrates which finds that: (1) motor patterns tend to be highly conserved among closely related taxa; (2) the ability to modulate motor patterns in response to different prey types appears to be a general property of teleost fish feeding mechanisms; and (3) variation in experimental EMG data is ubiquitous and, when unaccounted for, confounds comparisons among treatment groups.

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