The influence of temperature on mechanics of red muscle in carp.

Abstract

SUMMARY1. We measured the influence of temperature on maximum velocity of shortening (Vmax) of red muscle in carp in order to better understand the influence of temperature on locomotory performance.2. A stable red muscle bundle preparation containing about 100 muscle fibres was developed. The bundles could not be activated directly by electrical stimulation, but rather contained sufficient nervous tissue so that acetylcholine released from the nerve terminals caused activation of the muscle. A high level of activation was achieved (116 kN/m2) by adding a combination of a 1 mM-caffeine and 10-5 g/ml eserine to physiological Ringer solution and electrically stimulating the preparation.3. Force-velocity characteristics were determined at 10 and 20 0C by the force clamp method. The data were well fitted by a hyperbola not constrained to pass through P0 = 1 (where P0 is the isometric force). The mean Vmax at 10 'C was 3-55+0-26 muscle lengths/s (ML/s) (n = 6) and at 20 0C, 5-71 +0-29 ML/s (n = 6).The mean Q10 for Vmax was 1-63 + 0-07 (n = 6). The a/P0* (Hill constant) and P.* (where Po* is the extrapolated load at zero velocity) were 0-49 + 0-06 (n = 6) and *19 +0-04 (n = 6) respectively at 10 0C and 0-29+0-06 (n = 6) and 1-51 +0-20 (n = 6) respectively at 20 0C.4. The mean Q10 for maximum isometric tension was 113 + 0-02 (n = 6). The maximal power generation was 59-7 + 2-3 W/kg (n = 6) at 10 'C and 94-3 + 3-2 W/kg (n = 6) at 20 0C representing a Q10 of 1-58. The Q10 is less than the product of Q10s for P0 and Vm.. because of the greater curvature of the force-velocity curve at 20 0C.5. The 1-63-fold higher Vmax at 200C than at 10 0C enables fish to swim with a 1-6-fold faster muscle shortening velocity, V, at the higher temperature. Thus at both 10 and 20 0C, red muscle is used only over the same narrow range of V/Vmax (0-184-36),where isolated muscle experiments suggest that power and efficiency are maximal.Thus V/Vmax appears to be an effective design constraint which limits the range of velocities over which muscle is used in vivo at different temperatures.

The ultrastructure and contractile properties of a fast-acting, obliquely striated, myosin-regulated muscle: the funnel retractor of squids

“…Relative to other cross-striated muscles, the power output (in Wkg -1 ) of the longitudinal fibers is similar to that of the red fibers of carp (Rome and Sosnicki, 1990) and scup (Rome et al, 1992) at 10°C, and the FG portion of the iliofibularis of the lizard Dipsosaurus dorsalis at 15°C (Marsh and Bennett, 1985). The power output is quite low, however, relative to the fast-acting fibers of Xenopus laevis iliofibularis muscle at 20°C (Lännergren, 1987) and the flight muscles of katydids at 35°C (Josephson, 1984), even after accounting for differences in temperature.…”

Mechanical specialization of the obliquely striated circular mantle muscle fibres of the long-finned squidDoryteuthis pealeii

“…Milligan et al calculated power output from the force-velocity relationship of the CMP fibres of the loliginid squid Alloteuthis subulata. They noted that peak power output occurred at V/V max of about 0.38 and that the fibres produced high power over a fairly broad range of lengths, particularly compared to the cross striated fibres of a variety of vertebrates (Lännergren et al, 1982;Curtin and Woledge, 1988;Rome and Sosnicki, 1990;McLister et al, 1995). We estimated V/V max by using the strain rates (ε) calculated from the model as a proxy for the in vivo shortening velocity (V) of the circular fibres and the mean V max data from Fig.·7B.…”

The Effects of Temperature on the Feeding Performance of Invasive Fishes

“…As poikilotherms, variations in the feeding performance and ecology of invasive fishes are expected to be consistent with predictions based on the known effects of temperature on the physiology and ecology of heterothermic, aquatic animals [63]. For example, the velocity of fin propulsion during swimming and mouth-opening during feeding, behaviors fueled by skeletal-muscle contraction and relaxation, are expected to double when ambient temperature is increased by 10°C.This is because at the physiological level of analysis, there is a twofold increase in the rate of muscular contraction and relaxation for every 10°C increase in temperature [18][19][20][21][22][23]. At the ecological level of analysis, the food habit of some temperate fishes, such as largemouth bass, Micropterussalmoides, and pumpkinseed sunfish, Lepomisgibbosus, change seasonally, consistent with the seasonal cooling and warming of lakes or rivers in temperate ecosystems [64][65][66].…”

“…Our growing concern about the consequences of climate change, in general, and how global warming mediates the performance and spread of invasive species, in particular, underscores the need for contemporary research that addresses how the performance of invasive species is affected by environmental temperature [15][16][17]. Physiological processes such as metabolic rate, as well as contractile properties and mechanics of skeletal muscles are affected by body and environmental temperature [18][19][20][21][22][23][24]. For example, poikilotherms such as fishes swim and feed differently when subjected to varying levels of environmental temperature [21,[25][26][27][28][29][30][31].…”

“…Physiological processes such as metabolic rate, as well as contractile properties and mechanics of skeletal muscles are affected by body and environmental temperature [18][19][20][21][22][23][24]. For example, poikilotherms such as fishes swim and feed differently when subjected to varying levels of environmental temperature [21,[25][26][27][28][29][30][31]. The majority, if not all of existing literature deal with issues of invasive species apart from climate change phenomenon.…”