scholarly journals RECRUITMENT PATTERNS AND CONTRACTILE PROPERTIES OF FAST MUSCLE FIBRES ISOLATED FROM ROSTRAL AND CAUDAL MYOTOMES OF THE SHORT-HORNED SCULPIN

1993 ◽  
Vol 185 (1) ◽  
pp. 251-265 ◽  
Author(s):  
I. A. Johnston ◽  
C. E. Franklin ◽  
T. P. Johnson
Keyword(s):  
Power Output ◽  
High Speed ◽  
Prey Capture ◽  
The Body ◽  
Contractile Properties ◽  
Fast Muscle ◽  
Muscle Fibres ◽  
Length Changes ◽  
Tail Beat ◽  
Positive Work

Muscle action during swimming and the contractile properties of isolated muscle fibres were studied in the short-horned sculpin Myoxocephalus scorpius at 5°C. Semi-steady swimming, startle responses and prey-capture events were filmed with a high-speed video at 200 frames s-1, using fish 22–26 cm in total length (L). Electromyographical (EMG) recordings, synchronised with the video, were made from fast muscle in rostral and caudal myotomes at points 0.40L and 0.80L along the body. Fast muscle fibres were first recruited at tail-beat frequencies of 3.7-4.2 Hz, corresponding to a swimming speed of 1.7 L s-1. Electrical activity in the muscles occurred during 16–38 % of each tail- beat cycle regardless of frequency. Muscle fibres were activated during the lengthening phase of the cycle. In caudal myotomes, the onset of the muscle activity occurred at a phase of 75–105° at 3.7 Hz, decreasing to approximately 50° at frequencies greater than 4.5 Hz (0° phase was defined as the point at which muscle fibres passed through their resting lengths in the stretch phase of the cycle; a full cycle is 360°). Prey capture was a stereotyped behaviour consisting of a preparatory movement, a powerstroke at 7–9 Hz and a glide of variable duration. The delay between the activation of muscle fibres in rostral and caudal myotomes during prey capture and startle responses was approximately 10 ms. Fast muscle fibres isolated from rostral and caudal myotomes were found to have similar isometric contractile properties. Maximum tetanic stress was 220 kN m-2, and half-times for force development and relaxation were approximately 50 ms and 135 ms respectively. Power output was measured by the ‘work loop’ technique in muscle fibres subjected to sinusoidal length changes at the range of frequencies found during swimming. Under optimal conditions of strain and stimulation, muscle fibres from rostral and caudal myotomes produced similar levels of work (3.5 J kg-1) and generated their maximum power output of 25–30 W kg-1 at the tail-beat frequencies used in swimming (4–8 Hz). Progressively delaying the onset of stimulation relative to the start of the strain cycle resulted in an initial modest increase, followed by a decline, in the work per cycle. Maximum positive work and net negative work were done at stimulus phase values of 20–50° and 120–140° respectively. The EMG and swimming studies suggest that fast muscle fibres in both rostral and caudal myotomes do net positive work under most conditions.

How fish power predation fast-starts

1995 ◽  
Vol 198 (9) ◽  
pp. 1851-1861 ◽  
Author(s):  
I A Johnston ◽  
J L van Leeuwen ◽  
M L F Davies ◽  
T Beddow
Keyword(s):  
Tensile Stress ◽  
Muscle Mass ◽  
Power Output ◽  
Average Power ◽  
Temperature Acclimation ◽  
The Body ◽  
Fast Muscle ◽  
Muscle Fibres ◽  
Fast Start ◽  
Tail Beat

Short-horned sculpin (Myoxocephalus scorpius L.) were acclimated for 6­8 weeks to either 5 °C or 15 °C (12 h dark: 12 h light). Fast-starts elicited by prey capture were filmed from above in silhouette using a high-speed video camera (200 frames s-1). Outlines of the body in successive frames were digitised and changes in strain for the dorsal fast muscle calculated from a knowledge of backbone curvature and the geometrical arrangement of fibres. For 15 °C-acclimated fish at 15 °C, muscle strain amplitude (peak-to-peak) during the first tail-beat was approximately 0.16 at 0.32L, 0.19 at 0.52L and 0.15 at 0.77L, where L is the total length of the fish. Fast muscle fibres were isolated and subjected to the strains calculated for the first tail-beat of the fast-start (abstracted cycle). Preparations were electrically stimulated at various times after the initiation of the fast-start using an in vivo value of duty cycle (27 %). Prior to shortening, muscle fibres at 0.52L and 0.77L were subjected to a pre-stretch of 0.055l0 and 0.085l0 respectively (where l0 is resting muscle length). The net work per cycle was calculated from plots of fibre length and tensile stress. For realistic values of stimulus onset, the average power output per abstracted cycle was similar at different points along the body and was in the range 24­31 W kg-1 wet muscle mass. During shortening, the instantaneous power output reached 175­265 W kg-1 wet muscle mass in middle and caudal myotomes. At the most posterior position examined, the muscle fibres produced significant tensile stresses whilst being stretched, resulting in an initially negative power output. The fibres half-way down the trunk produced their maximum power at around the same time that caudal muscle fibres generated significant tensile stress. Fast muscle fibres at 0.37­0.66L produced 76 % of the total work done during the first tail-beat compared with only 14 % for fibres at 0.67­0.86L, largely reflecting differences in muscle mass. The effect of temperature acclimation on muscle power was determined using the strain fluctuations calculated for 0.52L. For 5 °C-acclimated fish, the average power per cycle (± s.e.m.; W kg-1 wet muscle mass) was 21.8±3.4 at 5 °C, falling to 6.3±1.8 at 15 °C. Following acclimation to 15 °C, average power per cycle increased to 23.8±2.8 W kg-1 wet muscle mass at 15 °C. The results indicate near-perfect compensation of muscle performance with temperature acclimation.

scholarly journals Scaling of Power Output in Fast Muscle Fibres of the Atlantic Cod During Cyclical Contractions

1992 ◽  
Vol 170 (1) ◽  
pp. 143-154 ◽  
Author(s):  
M. ELIZABETH ANDERSON ◽  
IAN A. JOHNSTON
Keyword(s):  
Steady State ◽  
Power Output ◽  
Standard Length ◽  
Atlantic Cod ◽  
Maximum Power ◽  
Fast Muscle ◽  
Muscle Fibres ◽  
Cycle Frequency ◽  
Maximum Power Output ◽  
Length Changes

Fast muscle fibres were isolated from abdominal myotomes of Atlantic cod (Gadus morhua L.) ranging in size from 10 to 63 cm standard length (Ls). Muscle fibres were subjected to sinusoidal length changes about their resting length (Lf) and stimulated at a selected phase of the strain cycle. The work performed in each oscillatory cycle was calculated from plots of force against muscle length, the area of the resulting loop being net work. Strain and the number and timing of stimuli were adjusted to maximise positive work per cycle over a range of cycle frequencies at 8°C. Force, and hence power output, declined with increasing cycles of oscillation until reaching a steady state around the ninth cycle. The strain required for maximum power output (Wmax) was ±7-11% of Lf in fish shorter than 18 cm standard length, but decreased to ±5 % of Lf in larger fish. The cycle frequency required for Wmax also declined with increasing fish length, scaling to Ls−0.51 under steady-state conditions (cycles 9–12). At the optimum cycle frequency and strain the maximum contraction velocity scaled to Ls−0.79. The maximum stress (Pmax) produced within a cycle was highest in the second cycle, ranging from 51.3 kPa in 10 cm fish to 81.8 kPa in 60 cm fish (Pmax=28.2Ls0.25). Under steady-state conditions the maximum power output per kilogram wet muscle mass was found to range from 27.5 W in a 10 cm Ls cod to 16.4 W in a 60 cm Ls cod, scaling with Ls−0.29 and body mass (Mb)−0.10 Note: To whom reprint requests should be sent

The Influence of Temperature on Muscle Velocity and Sustained Performance in Swimming Carp

1990 ◽  
Vol 154 (1) ◽  
pp. 163-178 ◽  
Author(s):  
LAWRENCE C. ROME ◽  
R. MCNEILL ALEXANDER
Keyword(s):  
Swimming Speed ◽  
High Speed ◽  
Sarcomere Length ◽  
Beat Frequency ◽  
Maximum Velocity ◽  
Muscle Fibres ◽  
Total Force ◽  
Red Muscle ◽  
Length Changes ◽  
Tail Beat

The aim of this study was to evaluate how fish locomote at different muscle temperatures. Sarcomere length excursion and muscle shortening velocity, V, were determined from high-speed motion pictures of carp, Cyprinus carpio (11–14 cm), swimming steadily at various sustained speeds at 10, 15 and 20°C. In the middle and posterior regions of the carp, sarcomeres of the lateral red muscle underwent cyclical excursions of 0.31 μm, centred around the resting length of 2.06 μm (i.e. from 1.91 to 2.22 μm). The amplitudes of the sarcomere length excursions were essentially independent of swimming speed and temperature. As tail-beat frequency increased linearly with swimming speed regardless of temperature, the sarcomeres underwent the same length changes in a shorter time. Thus, V increased in a linear and temperature-independent manner with swimming speed. Neither temperature nor swimming speed had an influence on tail-beat amplitude or tail height. Our findings indicate that muscle fibres are used only over a narrow, temperature-independent range of V/Vmax (0.17-0.36) where power and efficiency are maximal. Carp start to recruit their white muscles at swimming speeds where the red muscle V/Vmax becomes too high (and thus power output declines). When the V/Vmax of the active muscle falls too low during steady swimming, carp switch to ‘burst-and-coast’ swimming, apparently to keep V/Vmax high. Because Vmax (maximum velocity of shortening) of carp red muscle has a Q10 of 1.63, the transition speeds between swimming styles are lower at lower temperatures. Thus, carp recruit their white anaerobic muscle at a lower swimming speed at lower temperatures (verified by electromyography), resulting in a lower maximum sustainable swimming speed. The present findings also indicate that, to generate the same total force and power to swim at a given speed, carp at 10°C must recruit about 50% greater fibre cross-sectional area than they do at 20°C. Note: Present address: Department of Plant Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA. Present address: Department of Pure and Applied Biology, University of Leeds, Leeds LS2 9JT, England.

POWER OUTPUT OF FISH MUSCLE FIBRES PERFORMING OSCILLATORY WORK: EFFECTS OF ACUTE AND SEASONAL TEMPERATURE CHANGE

1991 ◽  
Vol 157 (1) ◽  
pp. 409-423 ◽  
Author(s):  
TIMOTHY P. JOHNSON ◽  
IAN A. JOHNSTON
Keyword(s):  
Strain Amplitude ◽  
Power Output ◽  
Muscle Length ◽  
Fast Muscle ◽  
Muscle Fibres ◽  
Work Output ◽  
Cycle Frequency ◽  
Maximum Power Output ◽  
Resting Muscle ◽  
Positive Work

Fast muscle fibres were isolated from the abdominal myotomes of the shorthorned sculpin Myoxocephalus scorpius L. Sinusoidal length changes were imposed about resting muscle length and fibres were stimulated at a selected phase during the strain cycle. The work output per cycle was calculated from the area of the resulting force-position loops. The strain amplitude required for maximum work per cycle had a distinct optimum at ±5 % of resting length, which was independent of temperature. Maximum positive work loops were obtained by retarding the stimulus relative to the start of the length-change cycle by 30° (full cycle=360°). The maximum negative work output was obtained with a 210° stimulus phase shift. At intermediate stimulus phase shifts, work loops became complex with both positive (anticlockwise) and negative (clockwise) components. The number and timing of stimuli were adjusted, at constant strain amplitude (±5% of resting muscle length), to optimize net positive work output over a range of cycle frequencies. The cycle frequency required for maximum power output (work per cycle times cycle frequency) increased from around 5–7 Hz at 4°C to 9–13 Hz at 15°C. The maximum tension generated per cycle at 15°C was around two times higher at all cycle frequencies in summer-relative to winter-acclimatized fish. Fast muscle fibres from summer fish produced consistently higher tensions at 4°C, but the differences were only significant at 15 Hz. Acclimatization also modified the relationship between peak length and peak force at 4°C and 15°C. The maximum power output of muscle fibres showed little seasonal variation at 4°C and was in the range 20–25 W kg−1. In contrast, at 15°C, maximum muscle power output increased from 9 W kg−1 in the winter- to 30 W kg−1 in the summeracclimatized fish

The mechanical power output of the flight muscles of blue-breasted quail (Coturnix chinensis) during take-off

2001 ◽  
Vol 204 (21) ◽  
pp. 3601-3619 ◽  
Author(s):  
Graham N. Askew ◽  
Richard L. Marsh ◽  
Charles P. Ellington
Keyword(s):  
Body Mass ◽  
Power Output ◽  
High Speed ◽  
The Body ◽  
Three Dimensions ◽  
Total Power ◽  
Muscle Fibres ◽  
Wingbeat Frequency ◽  
Mechanical Power Output ◽  
Flight Muscles

SUMMARYBlue-breasted quail (Coturnix chinensis) were filmed during take-off flights. By tracking the position of the centre of mass of the bird in three dimensions, we were able to calculate the power required to increase the potential and kinetic energy. In addition, high-speed video recordings of the position of the wings over the course of the wing stroke, and morphological measurements, allowed us to calculate the aerodynamic and inertial power requirements. The total power output required from the pectoralis muscle was, on average, 390 W kg–1, which was similar to the highest measurements made on bundles of muscle fibres in vitro (433 W kg–1), although for one individual a power output of 530 W kg–1 was calculated. The majority of the power was required to increase the potential energy of the body. The power output of these muscles is the highest yet found for any muscle in repetitive contractions.We also calculated the power requirements during take-off flights in four other species in the family Phasianidae. Power output was found to be independent of body mass in this family. However, the precise scaling of burst power output within this group must await a better assessment of whether similar levels of performance were measured across the group. We extended our analysis to one species of hawk, several species of hummingbird and two species of bee. Remarkably, we concluded that, over a broad range of body size (0.0002–5 kg) and contractile frequency (5–186 Hz), the myofibrillar power output of flight muscles during short maximal bursts is very high (360–460 W kg–1) and shows very little scaling with body mass. The approximate constancy of power output means that the work output varies inversely with wingbeat frequency and reaches values of approximately 30–60 J kg–1 in the largest species.

Quantitative analysis of prey-capture kinematics in Anolis equestris (Reptilia: Iguanidae)

1990 ◽  
Vol 68 (10) ◽  
pp. 2192-2198 ◽  
Author(s):  
Vincent L. Bels
Keyword(s):  
High Speed ◽  
Prey Capture ◽  
Anterior Part ◽  
The Body ◽  
Original Position ◽  
Forward Movement ◽  
Live Prey ◽  
Capture Process ◽  
Locomotor System ◽  
Cyclic Movement

High-speed cinematography was employed to study the mechanics of prey capture in Anolis equestris. Capture of live prey (adult locusts) consists of a cyclic movement of the upper and lower jaws combined with tongue protraction. Kinematic profiles are presented for the jaws, tongue, and forelimbs. The tongue is projected during the "slow open" stage and most of the "fast open" stage. The tongue protrudes beyond the mandibular symphysis during the slow open stage, and rotates simultaneously around a transverse anteromedian axis. The prey is thus contacted by the dorsal sticky surface of the tongue, and then pulled backward into the oral cavity by a combination of a forward movement of the jaws and retraction of the tongue. Gape angle, defined as the angle between the upper and lower jaws, continues to increase during the initial stages of tongue retraction. During the capture process, the anterior part of the body lunges forward, followed by a return to its original position; this displacement is mediated by the forelimbs, which usually remain well anchored to the floor. The cyclic food-capture movements of the jaws and tongue–hyoid system in A. equestris (Iguanidae) and Chameleo dilepis (Chamaeleontidae) are compared. I argue that one of the primary selection forces in the evolution of the different mechanisms of prey prehension in these two lizard groups was enhancement of the locomotor system and, consequently, foraging ability.

scholarly journals Hydrodynamics of linear acceleration in bluegill sunfish Lepomis macrochirus

2018 ◽  
Author(s):  
Tyler N. Wise ◽  
Margot A. B. Schwalbe ◽  
Eric D. Tytell
Keyword(s):  
Swimming Speed ◽  
High Speed ◽  
Fluid Dynamic ◽  
Natural Habitat ◽  
Lepomis Macrochirus ◽  
Linear Acceleration ◽  
High Amplitude ◽  
The Body ◽  
Bluegill Sunfish ◽  
Tail Beat

SUMMARY STATEMENTBluegill sunfish accelerate primarily by increasing the total amount of force produced in each tail beat but not by substantially redirecting forces.ABSTRACTIn their natural habitat, fish rarely swim steadily. Instead they frequently accelerate and decelerate. Relatively little is known about how fish produce extra force for acceleration in routine swimming behavior. In this study, we examined the flow around bluegill sunfish Lepomis macrochirus during steady swimming and during forward acceleration, starting at a range of initial swimming speeds. We found that bluegill produce vortices with higher circulation during acceleration, indicating a higher force per tail beat, but do not substantially redirect the force. We quantified the flow patterns using high speed video and particle image velocimetry and measured acceleration with small inertial measurement units attached to each fish. Even in steady tail beats, the fish accelerates slightly during each tail beat, and the magnitude of the acceleration varies. In steady tail beats, however, a high acceleration is followed by a lower acceleration or a deceleration, so that the swimming speed is maintained; in unsteady tail beats, the fish maintains the acceleration over several tailbeats, so that the swimming speed increases. We can thus compare the wake and kinematics during single steady and unsteady tailbeats that have the same peak acceleration. During unsteady tailbeats when the fish accelerates forward for several tailbeats, the wake vortex forces are much higher than those at the same acceleration during single tailbeats in steady swimming. The fish also undulates its body at higher amplitude and frequency during unsteady tailbeats. These kinematic changes likely increase the fluid dynamic added mass of the body, increasing the forces required to sustain acceleration over several tailbeats. The high amplitude and high frequency movements are also likely required to generate the higher forces needed for acceleration. Thus, it appears that bluegill sunfish face a tradeoff during acceleration: the body movements required for acceleration also make it harder to accelerate.

Swimming in needlefish (Belonidae): anguilliform locomotion with fins

2002 ◽  
Vol 205 (18) ◽  
pp. 2875-2884 ◽  
Author(s):  
James C. Liao
Keyword(s):  
Surface Waters ◽  
High Speed ◽  
Total Body Length ◽  
The Body ◽  
Pectoral Fins ◽  
Half Wavelength ◽  
Total Body ◽  
Length Analysis ◽  
Median Fins ◽  
Tail Beat

SUMMARYThe Atlantic needlefish (Strongylura marina) is a unique anguilliform swimmer in that it possesses prominent fins, lives in coastal surface-waters, and can propel itself across the surface of the water to escape predators. In a laboratory flow tank, steadily swimming needlefish perform a speed-dependent suite of behaviors while maintaining at least a half wavelength of undulation on the body at all times. To investigate the effects of discrete fins on anguilliform swimming, I used high-speed video to record body and fin kinematics at swimming speeds ranging from 0.25 to 2.0 Ls-1 (where L is the total body length). Analysis of axial kinematics indicates that needlefish are less efficient anguilliform swimmers than eels, indicated by their lower slip values. Body amplitudes increase with swimming speed, but unlike most fishes, tail-beat amplitude increases linearly and does not plateau at maximal swimming speeds. At 2.0 Ls-1, the propulsive wave shortens and decelerates as it travels posteriorly, owing to the prominence of the median fins in the caudal region of the body. Analyses of fin kinematics show that at 1.0 Ls-1 the dorsal and anal fins are slightly less than 180° out of phase with the body and approximately 225° out of phase with the caudal fin. Needlefish exhibit two gait transitions using their pectoral fins. At 0.25 L s-1, the pectoral fins oscillate but do not produce thrust, at 1.0 L s-1 they are held abducted from the body,forming a positive dihedral that may reduce rolling moments, and above 2.0 L s-1 they remain completely adducted.

IN VIVO MUSCLE LENGTH CHANGES IN BUMBLEBEES AND THE IN VITRO EFFECTS ON WORK AND POWER

1993 ◽  
Vol 183 (1) ◽  
pp. 101-113 ◽  
Author(s):  
K. M. Gilmour ◽  
C. P. Ellington
Keyword(s):  
High Speed ◽  
Time Course ◽  
Second Harmonic ◽  
Muscle Length ◽  
Muscle Fibres ◽  
Bombus Lucorum ◽  
Length Changes ◽  
In Vitro Effects

The amplitude and time course of muscle length changes were examined in vivo in tethered, flying bumblebees Bombus lucorum. A ‘window’ was cut in the dorsal cuticle and aluminium particles were placed on the exposed dorsal longitudinal muscle fibres. Muscle oscillations were recorded using high-speed video and a high-magnification lens. The amplitude of muscle length changes was 1.9 % (s.d.=0.5 %, N=7), corresponding to the commonly quoted strain of 1–3 % for asynchronous muscle. Higher harmonics, particularly the second, were found in the muscle oscillations and in the wing movements. The second harmonic for wing movements was damped in comparison to that for muscle length changes, probably as a result of compliance in the thoracic linkage. Inclusion of the second harmonic in the driving signal for in vitro experiments on glycerinated fibres generally resulted in a decrease in the work and power, but a substantial increase was found for some fibres.

MYOTOMAL MUSCLE FUNCTION AT DIFFERENT LOCATIONS IN THE BODY OF A SWIMMING FISH

1993 ◽  
Vol 182 (1) ◽  
pp. 191-206 ◽  
Author(s):  
J. D. Altringham ◽  
C. S. Wardle ◽  
C. I. Smith
Keyword(s):  
Power Output ◽  
Muscle Function ◽  
Muscle Activation ◽  
Muscle Power ◽  
Travelling Waves ◽  
The Body ◽  
Muscle Fibres ◽  
Cycle Frequency ◽  
Lateral Muscle

We describe experiments on isolated, live muscle fibres which simulate their in vivo activity in a swimming saithe (Pollachius virens). Superficial fast muscle fibres isolated from points 0.35, 0.5 and 0.65 body lengths (BL) from the anterior tip had different contractile properties. Twitch contraction time increased from rostral to caudal myotomes and power output (measured by the work loop technique) decreased. Power versus cycle frequency curves of rostral fibres were shifted to higher frequencies relative to those of caudal fibres. In the fish, phase differences between caudally travelling waves of muscle activation and fish bending suggest a change in muscle function along the body. In vitro experiments indicate that in vivo superficial fast fibres of rostral myotomes are operating under conditions that yield maximum power output. Caudal myotomes are active as they are lengthened in vivo and initially operate under conditions which maximise their stiffness, before entering a positive power-generating phase. A description is presented for the generation of thrust at the tail blade by the superficial, fast, lateral muscle. Power generated rostrally is transmitted to the tail by stiffened muscle placed more caudally. A transition zone between power generation and stiffening travels caudally, and all but the most caudal myotomes generate power at some phase of the tailbeat. Rostral power output, caudal force, bending moment and force at the tail blade are all maximal at essentially the same moment in the tailbeat cycle, as the tail blade crosses the swimming track.

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