J Exp Zool A Ecol Integr Physiol
October 2024
Slow and sustainable intermittent swimming has recently been described in several Centrarchid fishes, such as bluegill and largemouth bass. This swimming behavior involves short periods of body-caudal fin undulation alternating with variable periods of coasting. This aerobic muscle powered swimming appears to reduce energetic costs for slow, sustainable swimming, with fish employing a "fixed-gear" or constant tailbeat frequency and modulating swimming speed by altering the length of the coasting period.
View Article and Find Full Text PDFJ Exp Zool A Ecol Integr Physiol
December 2023
Locomotion is essential for the survival and fitness of animals. Fishes have evolved a variety of mechanisms to minimize the cost of transport. For instance, bluegill sunfish have recently been shown to employ intermittent swimming in nature and in laboratory conditions.
View Article and Find Full Text PDFComp Biochem Physiol A Mol Integr Physiol
June 2023
Thermal acclimation allows ectotherms to maintain physiological homeostasis while occupying habitats with constantly changing temperatures. This process is especially important in skeletal muscle which powers most movements necessary for life. We aimed to understand how fish skeletal muscle is impacted by acclimatization in the laboratory.
View Article and Find Full Text PDFBatoids differ from other elasmobranch fishes in that they possess dorsoventrally flattened bodies with enlarged muscled pectoral fins. Most batoids also swim using either of two modes of locomotion: undulation or oscillation of the pectoral fins. In other elasmobranchs (e.
View Article and Find Full Text PDFComp Biochem Physiol A Mol Integr Physiol
February 2023
As climate change alters the thermal environment of the planet, interest has grown in how animals may mitigate the impact of a changing environment on physiological function. Thermal acclimation to a warm environment may, for instance, blunt the impact of a warming environment on metabolism by allowing a fish to shift to slower isoforms of functionally significant proteins such as myosin heavy chain. The thermal acclimation of brook trout (Salvelinus fontinalis) was examined by comparing swimming performance, myotomal muscle contraction kinetics and muscle histology in groups of fish acclimated to 4, 10 and 20 °C.
View Article and Find Full Text PDFIn response to accelerated temperature shifts due to climate change, the survival of many species will require forms of thermal acclimation to their changing environment. We were interested in how climate change will impact a commercially and recreationally important species of fish, Atlantic salmon (Salmo salar). As climate change alters the thermal environment of their natal streams, we asked how their muscle function will be altered by extended exposure to both warm and cold temperatures.
View Article and Find Full Text PDFGroup swimming size influences metabolic energy consumption and swimming behaviour in fishes. Hydrodynamic flows and vortices of other fish are thought to be beneficial in terms of the energetic costs of swimming. Similarly, abiotic obstructions have been shown to have similar benefits with respect to metabolic consumption in swimming fish such as rainbow trout Oncorhynchus mykiss.
View Article and Find Full Text PDFTemperature can be a key abiotic factor in fish distribution, as it affects most physiological processes. Specifically, temperature can affect locomotor capabilities, especially as species are exposed to temperatures nearing their thermal limits. In this study, we aimed to understand the effects of temperature on muscle in two labrids that occupy the Northwest Atlantic Ocean.
View Article and Find Full Text PDFJ Exp Zool A Ecol Integr Physiol
December 2018
Climate change affects the thermal environment of aquatic organisms. Changes in the thermal environment may affect muscle function in the eurythermal rainbow smelt, Osmerus mordax, and relatively more stenothermal rainbow trout, Oncorhynchus mykiss. Literature suggests that the trout will be more sensitive to changes in environmental temperature, as they experience a more limited range of environmental temperatures.
View Article and Find Full Text PDFGlutamate-activated α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPA-Rs) mediate the majority of excitatory neurotransmission in brain and thus are major drug targets for diseases associated with hyperexcitability or neurotoxicity. Due to the critical nature of AMPA-Rs in normal brain function, typical AMPA-R antagonists have deleterious effects on cognition and motor function, highlighting the need for more precise modulators. A dramatic increase in the flip isoform of alternatively spliced AMPA-R GluA1 subunits occurs post-seizure in humans and animal models.
View Article and Find Full Text PDFPremise Of Study: Deciduous woody species invest considerable resources in the growth of new foliage and distal stems. This new growth is at risk for mechanical damage from high winds and storms. Pawpaw has large leaves borne distally on thin twigs.
View Article and Find Full Text PDFComp Biochem Physiol A Mol Integr Physiol
June 2016
Rainbow smelt (Osmerus mordax), a eurythermal fish, live in environments from -1.8 to 20°C, with some populations facing substantial annual variation in environmental temperature. These different temperature regimes pose distinct challenges to locomotion by smelt.
View Article and Find Full Text PDFRainbow smelt, Osmerus mordax, experience a wide range of temperatures in their native habitat. In response to cold, smelt express anti-freeze proteins and the osmolytes glycerol, trimethylamine N-oxide (TMAO) and urea to avoid freezing. The physiological influences of these osmolytes are not well understood.
View Article and Find Full Text PDFJ Exp Zool A Ecol Genet Physiol
March 2015
Swimming in fishes is powered by myotomal red, white and pink skeletal muscle. Slow swimming is powered by the red (slow-twitch muscle), fast speeds are achieved by the white (fast-twitch) muscle and pink muscle apparently serves an intermediate function. In recent years, the physiological properties and molecular composition of red (slow) and white (fast) muscle fibers have been well studied, while the intermediate pink muscle, which falls in a thin sheet between the superficial red muscle and deeper white muscle, has received less attention.
View Article and Find Full Text PDFRainbow smelt (Osmerus mordax) display an impressive ability to acclimate to very cold water temperatures. These fish express both anti-freeze proteins and glycerol in their plasma, liver, muscle and other tissues to avoid freezing at sub-zero temperatures. Maintenance of glycerol levels requires active feeding in very cold water.
View Article and Find Full Text PDFComp Biochem Physiol A Mol Integr Physiol
January 2010
This study examines the role of a myoplasmic protein, parvalbumin, in enhancing muscle relaxation by fishes. Parvalbumin is thought to bind free Ca(2+) during muscle contraction, thereby reducing intracellular [Ca(2+)] in muscle and speeding muscle relaxation by reducing Ca(2+) availability to the troponin complex. We hypothesized that parvalbumin expression is ubiquitously expressed in fish muscle and that its expression levels and role in muscle relaxation would depend on the activity level and the thermal environment of a given fish species.
View Article and Find Full Text PDFThe 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.
View Article and Find Full Text PDFJ Exp Zool A Ecol Genet Physiol
March 2008
Muscle's contractile properties can vary along different trajectories, including between muscle fiber types, along the body (within a muscle fiber type), and between developmental stages. This study explores the role of the regulatory myosin light chain (MLC2) in modulating contractile properties in rainbow trout myotomal muscle. Rainbow trout show longitudinal variations in muscle activation and relaxation, with faster contractile properties in the anterior myotome.
View Article and Find Full Text PDFComp Biochem Physiol A Mol Integr Physiol
August 2007
Rainbow trout (Oncorhynchus mykiss) display longitudinal and developmental shifts in muscle relaxation rate. This study aimed to determine the role of variations in parvalbumin content in modulating muscle relaxation. Parvalbumin is a low molecular weight protein that buffers myoplasmic Ca2+ and enhances muscle relaxation.
View Article and Find Full Text PDFComp Biochem Physiol A Mol Integr Physiol
December 2006
Recent work has employed video and sonometric analysis combined with hydrodynamic modeling to estimate power output by the feeding musculature of largemouth bass in feeding trials. The result was an estimate of approximately 69 W kg(-1) of power by the epaxial muscle during maximal feeding strikes. The present study employed in vitro measurements of force, work and power output by fast-twitch epaxial muscle bundles stimulated under activation conditions measured in vivo to evaluate the power output results of the feeding experiments.
View Article and Find Full Text PDFParvalbumin is a muscle protein that aids in relaxation from contraction. Parvalbumin binds myoplasmic Ca(2+) during contractions, reducing calcium concentration and enhancing relaxation. Different isoforms of parvalbumin have varying affinities for calcium, and relaxation rates in skeletal muscle may be affected by variations in the isoforms of parvalbumin expressed.
View Article and Find Full Text PDFRed or aerobic muscle from the anterior of rainbow trout Oncorhynchus mykiss activates (generates force) more quickly than that from the posterior. TnT is a component of the troponin complex that modulates muscle activation once Ca(2+) is bound. Since trout express at least two forms of TnT in their red muscle (S1 and S2), the differential expression of these two forms was predicted to explain variations in contractile properties.
View Article and Find Full Text PDFComp Biochem Physiol A Mol Integr Physiol
January 2004
Rainbow trout (Oncorhynchus mykiss) and brook trout (or charr, Salvelinus fontinalis) display different rostral-caudal patterns of power production by the red or aerobic muscle during steady swimming. The anterior muscle of rainbow trout produces much less power for swimming than the posterior, while in brook trout there is no variation in power output. To determine if red muscle recruitment is associated with anterior-posterior patterns of power production, electromyography (EMG) was used to record red muscle activity at three body positions across a range of swimming speeds in fish of each species.
View Article and Find Full Text PDFIntegr Comp Biol
April 2002
Salmonids undergo a developmental transition from parr to smolt that involves a number of physiological and morphological changes. In recent years, my laboratory has studied shifts in red muscle function at this parr-smolt transformation (PST) in rainbow trout, Oncorhynchus mykiss. Parr red muscle has faster contraction kinetics than smolts, including faster rates of activation and relaxation and a faster maximum shortening velocity.
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