scholarly journals Bifunctional Role of the Sternohyoideus Muscle During Suction Feeding in Striped Surfperch, Embiotoca lateralis

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
J J Lomax ◽  
T F Martinson ◽  
Y E Jimenez ◽  
E L Brainerd
Keyword(s):  
Muscle Mass ◽  
Muscle Power ◽  
Micropterus Salmoides ◽  
Lepomis Macrochirus ◽  
Muscle Length ◽  
Muscle Size ◽  
Suction Feeding ◽  
Shortening Velocity ◽  
Axial Muscle ◽  
Embiotoca Lateralis

Synopsis In ray-finned fishes, the sternohyoideus (SH) is among the largest muscles in the head region and, based on its size, can potentially contribute to the overall power required for suction feeding. However, the function of the SH varies interspecifically. In largemouth bass (Micropterus salmoides) and several clariid catfishes, the SH functions similarly to a stiff ligament. In these species, the SH remains isometric and transmitts power from the hypaxial musculature to the hyoid apparatus during suction feeding. Alternatively, the SH can shorten and contribute muscle power during suction feeding, a condition observed in the bluegill sunfish (Lepomis macrochirus) and one clariid catfish. An emerging hypothesis centers on SH muscle size as a predictor of function: in fishes with a large SH, the SH shortens during suction feeding, whereas in fish with a smaller SH, the muscle may remain isometric. Here, we studied striped surfperch (Embiotoca lateralis), a species in which the SH is relatively large at 8.8% of axial muscle mass compared with 4.0% for L. macrochirus and 1.7% for M. salmoides, to determine whether the SH shortens during suction feeding and is, therefore, bifunctional—both transmitting and generating power—or remains isometric and only transmits power. We measured skeletal kinematics of the neurocranium, urohyal, and cleithrum with Video Reconstruction of Moving Morphology, along with muscle strain and shortening velocity in the SH and epaxial muscles, using a new method of 3D external marker tracking. We found mean SH shortening during suction feeding strikes (n = 22 strikes from four individual E. lateralis) was 7.2 ± 0.55% (±SEM) of initial muscle length. Mean peak speed of shortening was 4.9 ± 0.65 lengths s−1, and maximum shortening speed occurred right around peak gape when peak power is generated in suction feeding. The cleithrum of E. lateralis retracts and depresses but the urohyal retracts and depresses even more, a strong indicator of a bifunctional SH capable of not only generating its own power but also transmitting hypaxial power to the hyoid. While power production in E. lateralis is still likely dominated by the axial musculature, since even the relatively large SH of E. lateralis is only 8.8% of axial muscle mass, the SH may contribute a meaningful amount of power given its continual shortening just prior to peak gape across all strikes. These results support the finding from other groups of fishes that a large SH muscle, relative to axial muscle mass, is likely to both generate and transmit power during suction feeding.

MUSCLE BULGING REDUCES MUSCLE FORCE AND LIMITS THE MAXIMAL EFFECTIVE MUSCLE SIZE

2006 ◽  
Vol 06 (03) ◽  
pp. 229-239 ◽  
Author(s):  
KARL DAGGFELDT
Keyword(s):  
Muscle Force ◽  
Muscle Length ◽  
Biomechanical Model ◽  
Muscle Performance ◽  
Muscle Size ◽  
Intramuscular Pressure ◽  
Shortening Velocity ◽  
Muscle Shortening ◽  
Force Reduction ◽  
Total Muscle

A biomechanical model was generated in order to investigate the possible mechanisms behind reductions in muscle performance due to muscle bulging. It was shown that the proportion of fiber force contributing to the total muscle force is reduced with fiber bulging and that the cause of this reduction is due to the intramuscular pressure (IMP) created by the bulging fibers. Moreover, it was established that the amount of IMP generated muscle force reduction is determined by the extent to which muscle thickening restricts muscle fibers from shortening, thereby limiting their power contribution. It was shown that bulging can set a limit to the maximal size a muscle can take without losing force and power producing capability. Possible effects, due to bulging, on maximal muscle force in relation to both muscle length and muscle shortening velocity were also demonstrated by the model.

Structure-function correlation in airway smooth muscle adapted to different lengths

2003 ◽  
Vol 285 (2) ◽  
pp. C384-C390 ◽  
Author(s):  
Kuo-Hsing Kuo ◽  
Ana M. Herrera ◽  
Lu Wang ◽  
Peter D. Paré ◽  
Lincoln E. Ford ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Airway Smooth Muscle ◽  
Muscle Power ◽  
Isometric Force ◽  
Muscle Length ◽  
Length Change ◽  
Cell Length ◽  
Myosin Filament ◽  
Shortening Velocity ◽  
Cross Sectional

Airway smooth muscle is able to adapt and maintain a nearly constant maximal force generation over a large length range. This implies that a fixed filament lattice such as that found in striated muscle may not exist in this tissue and that plastic remodeling of its contractile and cytoskeletal filaments may be involved in the process of length adaptation that optimizes contractile filament overlap. Here, we show that isometric force produced by airway smooth muscle is independent of muscle length over a twofold length change; cell cross-sectional area was inversely proportional to cell length, implying that the cell volume was conserved at different lengths; shortening velocity and myosin filament density varied similarly to length change: increased by 69.4% ± 5.7 (SE) and 76.0% ± 9.8, respectively, for a 100% increase in cell length. Muscle power output, ATPase rate, and myosin filament density also have the same dependence on muscle cell length: increased by 35.4% ± 6.7, 34.6% ± 3.4, and 35.6% ± 10.6, respectively, for a 50% increase in cell length. The data can be explained by a model in which additional contractile units containing myosin filaments are formed and placed in series with existing contractile units when the muscle is adapted at a longer length.

scholarly journals Feeding muscles scale differently from swimming muscles in sunfish (Centrarchidae)

2008 ◽  
Vol 5 (2) ◽  
pp. 274-277 ◽  
Author(s):  
Andrew M Carroll ◽  
Ashley M Ambrose ◽  
Terri A Anderson ◽  
David J Coughlin
Keyword(s):  
Muscle Activation ◽  
Micropterus Salmoides ◽  
Lepomis Macrochirus ◽  
Contractile Properties ◽  
Shortening Velocity ◽  
Physiological Properties ◽  
The Family ◽  
High Power Output ◽  
Myotomal Muscle ◽  
Vertebrate Skeletal Muscle

The physiological properties of vertebrate skeletal muscle typically show a scaling pattern of slower contractile properties with size. In fishes, the myotomal or swimming muscle reportedly follows this pattern, showing slower muscle activation, relaxation and maximum shortening velocity ( V max ) with an increase in body size. We asked if the muscles involved in suction feeding by fishes would follow the same pattern. We hypothesized that feeding muscles in fishes that feed on evasive prey are under selection to maintain high power output and therefore would not show slower contractile properties with size. To test this, we compared contractile properties in feeding muscles (epaxial and sternohyoideus) and swimming muscle (myotomal) for two members of the family Centrarchidae (sunfish): the bluegill ( Lepomis macrochirus ) and the largemouth bass ( Micropterus salmoides ). Consistent with our predictions, the V max of myotomal muscle in both species slowed with size, while the epaxials showed no significant change in V max with size. In the sternohyoideus, V max slowed with size in the bluegill but increased with size in the bass. The results indicate that scaling patterns of contractile properties appear to be more closely tied to muscle function (i.e. locomotion versus feeding) than overall patterns of size.

scholarly journals A biomechanical paradox in fish: swimming and suction feeding produce orthogonal strain gradients in the axial musculature

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yordano E. Jimenez ◽  
Richard L. Marsh ◽  
Elizabeth L. Brainerd
Keyword(s):  
High Power ◽  
Strain Gradient ◽  
Power Output ◽  
Lepomis Macrochirus ◽  
Bluegill Sunfish ◽  
Muscle Strain ◽  
Suction Feeding ◽  
Optimal Velocity ◽  
Axial Muscle ◽  
Axial Musculature

AbstractThe axial musculature of fishes has historically been characterized as the powerhouse for explosive swimming behaviors. However, recent studies show that some fish also use their ‘swimming’ muscles to generate over 90% of the power for suction feeding. Can the axial musculature achieve high power output for these two mechanically distinct behaviors? Muscle power output is enhanced when all of the fibers within a muscle shorten at optimal velocity. Yet, axial locomotion produces a mediolateral gradient of muscle strain that should force some fibers to shorten too slowly and others too fast. This mechanical problem prompted research into the gearing of fish axial muscle and led to the discovery of helical fiber orientations that homogenize fiber velocities during swimming, but does such a strain gradient also exist and pose a problem for suction feeding? We measured muscle strain in bluegill sunfish, Lepomis macrochirus, and found that suction feeding produces a gradient of longitudinal strain that, unlike the mediolateral gradient for locomotion, occurs along the dorsoventral axis. A dorsoventral strain gradient within a muscle with fiber architecture shown to counteract a mediolateral gradient suggests that bluegill sunfish should not be able to generate high power outputs from the axial muscle during suction feeding—yet prior work shows that they do, up to 438 W kg−1. Solving this biomechanical paradox may be critical to understanding how many fishes have co-opted ‘swimming’ muscles into a suction feeding powerhouse.

scholarly journals Effect of the Human Utilization of Northern Snakehead (Channa argus Cantor, 1842) on the Settlement of Exotic Fish and Cladoceran Community Structure

2021 ◽  
Vol 13 (5) ◽  
pp. 2486
Author(s):  
Jong-Yun Choi ◽  
Seong-Ki Kim
Keyword(s):  
Community Structure ◽  
Fish Species ◽  
Micropterus Salmoides ◽  
Lepomis Macrochirus ◽  
Nakdong River ◽  
Exotic Fish ◽  
Carnivorous Fish ◽  
Channa Argus ◽  
The Nakdong River ◽  
Exotic Fish Species

Empirical studies suggest that changes in the density of top predators, such as carnivorous fish, in freshwater food webs, strongly affect not only fish communities but also various primary and secondary consumers. Based on these findings, we explored how differences in the utilization of carnivorous fish (i.e., Northern Snakehead, Channa argus) by humans affected the fish and cladoceran community structure as well as the settlement of exotic fish species (i.e., Lepomis macrochirus and Micropterus salmoides) in 30 wetlands located in the upper and lower reaches of the Nakdong River. Our results show that in the mid–lower reaches of the Nakdong River, the density of C. argus was low, while high densities of L. macrochirus and M. salmoides were observed. Exotic fish species are frequently consumed by C. argus, leading to a low density of L. macrochirus and M. salmoides in the upper reaches, which supported a high density of C. argus. However, in the mid–lower reaches, the density of L. macrochirus was high because of the frequent collection of C. argus by fishing activities. The dominance of L. macrochirus significantly changed the structure of cladoceran communities. L. macrochirus mainly feeds on pelagic species, increasing the density of epiphytic species in the mid–lower reaches. The continued utilization of C. argus by humans induced a stable settlement of exotic fish species and strongly affected the community structures of primary consumers in the 30 wetlands. The frequency of C. argus collection has to be reduced to secure biodiversity in the mid–lower reaches of the Nakdong River, which will reduce the proportion of exotic fish species and increase the conservation of native fish.

Quantitative comparisons of the morphology and ultrastructure of erythrocyte nuclei from seven freshwater fish species

1995 ◽  
Vol 73 (10) ◽  
pp. 1951-1959 ◽  
Author(s):  
Charles H. Jagoe ◽  
Dave A. Welter
Keyword(s):  
Fish Species ◽  
Yellow Perch ◽  
Micropterus Salmoides ◽  
Lepomis Macrochirus ◽  
Nuclear Size ◽  
Image Analysis System ◽  
Cell Nuclei ◽  
Homogeneous Population ◽  
Differentiated Cells ◽  
Rainbow Trout Oncorhynchus Mykiss

Chromosome number and genomic DNA content vary widely among fish species, and ploidy can vary within species. This suggests that the size, shape, and morphological features of cell nuclei may also vary. Nucleated erythrocytes of fish are an easily sampled homogeneous population of differentiated cells ideal for inter- and intra-species comparisons. We collected blood samples from largemouth bass (Micropterus salmoides), bluegill (Lepomis macrochirus), chain pickerel (Esox niger), yellow perch (Perca flavescens), mosquitofish (Gambusia holbrooki), redeye bass (Micropterus coosae), and rainbow trout (Oncorhynchus mykiss) and removed cytoplasm and nuclear membranes from blood cells. Individual nuclei were examined and measured using scanning electron microscopy and a computerized image analysis system, and inter- and intra-species differences evaluated by nested analysis of variance. Nuclear size and shape varied significantly among species. Isolated nuclei had conspicuous apertures or holes, and the number and size of these holes also varied significantly among species. Variations in nuclear size and structure within species were small compared with interspecies differences. Little is known of the ultrastructure of erythrocyte nuclei in lower vertebrates, but their structure differs considerably from that of other vertebrate non-erythroid cells, suggesting that the organization of their DNA and associated proteins may be different.

MO612THE ROLE OF MECHANICAL MUSCLE POWER IN PHYSICAL DYSFUNCTION: A MODEL FOR TAILORING RESISTANCE-BASED REHABILITATION IN CHRONIC KIDNEY DISEASE

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
Thomas Wilkinson ◽  
Eleanor Gore ◽  
Jared Palmer ◽  
Luke Baker ◽  
Emma Watson ◽  
...  
Keyword(s):  
Activities Of Daily Living ◽  
Strength Training ◽  
Physical Function ◽  
Muscle Mass ◽  
Gait Speed ◽  
Daily Living ◽  
Muscle Power ◽  
Mechanical Power ◽  
Relative Power

Abstract Background and Aims Individuals living with CKD are characterised by adverse changes in physical function. Knowledge of the factors that mediate impairments in physical functioning is crucial for developing effective interventions that preserve mobility and future independence. Mechanical muscle power describes the rate of performing work and is the product of muscular force and velocity of contraction. Muscle power has been shown to have stronger associations with functional limitations and mortality than sarcopenia in older adults. In CKD, the role of mechanical muscle power is poorly understood and is overlooked as a target in many rehabilitation programmes, often at the expense of muscle mass or strength. The aims of this study were to 1) explore the prevalence of low absolute mechanical power, low relative mechanical power, and low specific mechanical power in CKD; and 2) investigate the association of mechanical power with the ability to complete activities of daily living and physical performance. Method Mechanical muscle power (relative, allometric, specific) was calculated using the sit-to-stand-5 (STS5) test as per previously validated equations. Legs lean mass was derived from regional analyses conducted using bioelectrical impedance analysis (BIA). Physical performance was assessed using two objective tests: usual gait speed and the ‘time-up-and-go’ (TUAG) test. Self-reported activities of daily living (ADLs) were assessed via the Duke Activity Status Index (DASI). Balance and postural stability (postural sway and velocity) was assessed using a FysioMeter. Sex-specific tertiles were used to determine low, medium and high levels of relative STS power and its main components. Results 102 participants with non-dialysis CKD were included (mean age: 62.0 (±14.1) years, n=49 males (48%), mean eGFR: 38.0 (±21.5) ml.min.1.73m2). The mean estimated relative power was 3.1 (±1.5) W.kg in females and 3.3 (±1.3) W.kg in males. Low relative power was found in 35/102 (34%) patients. Relative power was a significant independent predictor of self-reported ADLs (via the DASI) (B=.413, P=.004), and performance on the TUAG (B=-.719, P<.001) and gait speed (B=.404, P=.003) tests. Skeletal muscle mass was not associated with the DASI or any of the objective function tests Conclusion Patients presenting with low muscle power would benefit from participation in appropriate interventions designed to improve the physiological components accounting for low relative muscle power. Assessment of power can be used to tailor renal rehabilitation programmes as shown in Figure 1. Incorporation of power-based training, a novel type of strength training, designed by manipulating traditional strength training variables and primarily movement velocity and training intensity may present the best strategy for improving physical function in CKD.

scholarly journals Freshwater fishes of Bontebok National Park

Koedoe ◽  
2001 ◽  
Vol 44 (2) ◽  
Author(s):  
I.A. Russell
Keyword(s):  
South African ◽  
National Park ◽  
Fish Assemblages ◽  
Micropterus Salmoides ◽  
Clarias Gariepinus ◽  
Lepomis Macrochirus ◽  
River System ◽  
Indigenous Species ◽  
Freshwater Species ◽  
Micropterus Dolomieu

Fish assemblages were sampled at six sites in the Breede River in the Bontebok National Park during 1999 and 2000. A total of 380 fish from 12 species was recorded. Indigenous fish collected included one freshwater species (Barbus andrewi), two catodromous species (Anguilla mossambica, Myxus capensis). and three estuarine species (Gilchris- tella aestuaria, Monodactylusfalciformis, Mugil cephalus). Four of the species recorded were aliens (Tinea tinea, Lepomis macrochirus, Micropterus salmoides, Micropterus dolomieu) and two species translocated from other South African rivers (Tilapia sparrmanii, Clarias gariepinus). A further two indigenous species (Sandelia capensis, Pseudobarbus biirchelli) could potentially occur within the park, though the high abundance of alien predators means that there is little chance for recolonisation from tributaries higher in the Breede River system. There is little opportunity to meaningfully conserve most indigenous freshwater fish in Bontebok National Park.

scholarly journals A Systematic Review with Meta-Analysis of the Effect of Resistance Training on Whole-Body Muscle Growth in Healthy Adult Males

2020 ◽  
Vol 17 (4) ◽  
pp. 1285 ◽  
Author(s):  
Pedro J. Benito ◽  
Rocío Cupeiro ◽  
Domingo J. Ramos-Campo ◽  
Pedro E. Alcaraz ◽  
Jacobo Á. Rubio-Arias
Keyword(s):  
Systematic Review ◽  
Resistance Training ◽  
Muscle Mass ◽  
Meta Analysis ◽  
Muscle Growth ◽  
Fat Free Mass ◽  
Muscle Size ◽  
Whole Body ◽  
Cochrane Library ◽  
Significant Variable

We performed a systematic review and meta-analysis to study all published clinical trial interventions, determined the magnitude of whole-body hypertrophy in humans (healthy males) and observed the individual responsibility of each variable in muscle growth after resistance training (RT). Searches were conducted in PubMed, Web of Science and the Cochrane Library from database inception until 10 May 2018 for original articles assessing the effects of RT on muscle size after interventions of more than 2 weeks of duration. Specifically, we obtain the variables fat-free mass (FMM), lean muscle mass (LMM) and skeletal muscle mass (SMM). The effects on outcomes were expressed as mean differences (MD) and a random-effects meta-analysis and meta-regressions determined covariates (age, weight, height, durations in weeks…) to explore the moderate effect related to the participants and characteristics of training. One hundred and eleven studies (158 groups, 1927 participants) reported on the effects of RT for muscle mass. RT significantly increased muscle mass (FFM+LMM+SMM; Δ1.53 kg; 95% CI [1.30, 1.76], p < 0.001; I2 = 0%, p = 1.00). Considering the overall effects of the meta-regression, and taking into account the participants’ characteristics, none of the studied covariates explained any effect on changes in muscle mass. Regarding the training characteristics, the only significant variable that explained the variance of the hypertrophy was the sets per workout, showing a significant negative interaction (MD; estimate: 1.85, 95% CI [1.45, 2.25], p < 0.001; moderator: -0.03 95% CI [−0.05, −0.001] p = 0.04). In conclusion, RT has a significant effect on the improvement of hypertrophy (~1.5 kg). The excessive sets per workout affects negatively the muscle mass gain.

scholarly journals Association between vitamin D deficiency and exercise capacity in patients with CKD, a cross-sectional analysis

2020 ◽  
Author(s):  
Emma L Watson ◽  
Thomas J Wilkinson ◽  
Tom F O’Sullivan ◽  
Luke A Baker ◽  
Douglas W Gould ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Vitamin D ◽  
Vitamin D Deficiency ◽  
Exercise Capacity ◽  
Muscle Mass ◽  
Ex Vivo ◽  
Muscle Size ◽  
Cross Sectional ◽  
Cross Sectional Analysis ◽  
Sectional Analysis

AbstractEvidence is growing for a role of vitamin D in regulating skeletal muscle mass, strength and functional capacity. Given the role the kidneys play in activating total vitamin D, and the high prevalence of vitamin D deficiency in Chronic Kidney Disease (CKD), it is possible that deficiency contributes to the low levels of physical function and muscle mass in these patients. This is a secondary cross-sectional analysis of previously published interventional study, with ex vivo follow up work. 34 CKD patients at stages G3b-5 (eGFR 25.5 ± 8.3ml/min/1.73m2; age 61 ± 12 years) were recruited, with a sub-group (n=20) also donating a muscle biopsy. Vitamin D and associated metabolites were analysed in plasma by liquid chromatography tandem-mass spectroscopy and correlated to a range of physiological tests of muscle size, function, exercise capacity and body composition. The effects of 1α,25(OH)2D3 supplementation on myogenesis and myotube size was investigated in primary skeletal muscle cells from vitamin D deficient donors. In vivo, there was no association between total or active vitamin D and muscle size or strength, but a significant correlation with was seen with the total form. Ex vivo, 1α,25(OH)2D3 supplementation reduced IL-6 mRNA expression, but had no effect upon proliferation, differentiation or myotube diameter. This early preliminary work suggests that vitamin D deficiency is not a prominent factor driving the loss of muscle mass in CKD, but may play a role in reduced exercise capacity.

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