Characteristics of myotomal muscle fibres and their possible relation to growth rate in eels—Anguilla anguilla (L.) (Pisces, Teleostei)

Aquaculture ◽  
1976 ◽  
Vol 8 (3) ◽  
pp. 251-258 ◽  
Author(s):  
J.J. Willemse
1993 ◽  
Vol 183 (1) ◽  
pp. 137-147 ◽  
Author(s):  
N. A. Curtin ◽  
R. C. Woledge

Net work output and heat production of white myotomal muscle fibres from the dogfish were measured during complete cycles of sinusoidal movement at 12°C. The peak-to-peak movement was about 9 % of the muscle fibre length; three stimuli at 32 ms intervals were given in each mechanical cycle. The frequency of movement and the timing of the stimulation were varied for each preparation to find the optimal conditions for power output and those optimal for efficiency (the ratio of net work output to total energy output as heat+work). To achieve either maximum power or maximum efficiency, the tetanus must start while the muscle fibres are being stretched, before the beginning of the shortening part of the mechanical cycle. The highest power output, averaged over one cycle, was 0.23+/−0.014 W g-1 dry mass (+/−s.e.m., N=9, 46.9+/−2.8 mW g-1 wet mass) and was produced during movement at 3.5 Hz. The highest efficiency, 0.41+/−0.02 (+/−s.e.m., N=13), occurred during movements at 2.0-2.5 Hz. This value is higher than the efficiency previously measured during isovelocity shortening of these fibres. The implications of the high efficiency for crossbridge models of muscle contraction are discussed.


2015 ◽  
Vol 73 (1) ◽  
pp. 158-164 ◽  
Author(s):  
Michael I. Pedersen ◽  
Gorm H. Rasmussen

Abstract Stocking of young eel is widely practised, as a measure, to meet the management target of the EU eel recovery plan. The target of the recovery plan is to increase the escapement to 40% silver eel biomass, relative to pristine conditions. The scientific information to predict the outcome in silver eel biomass from stocking is limited and may depend on whether translocation of wild glass eel or yellow eel is used, or if the stocked eels used are yellow eel from aquaculture. We evaluated the yield from stocking two different sizes, 3 and 9 g eels from aquaculture. A professional fishery recaptured 12.7% of the 3 g and 9.4% of the 9 g eels, originally stocked. Growth rate and mortality rate were different for the two stocked sizes, favouring the small eels. Brutto yield per recruit (YPR) was 13 and 9.2 g and netto YPR was 9.8 and 0.31 g for 3 and 9 g eel, respectively. We conclude that there seems to be no advantage in using larger 9 g eels compared with small 3 g eels for stocking.


2007 ◽  
Vol 64 (7) ◽  
pp. 1414-1422 ◽  
Author(s):  
Janek Simon

Abstract Simon, J. 2007. Age, growth, and condition of European eel (Anguilla anguilla) from six lakes in the River Havel system (Germany). – ICES Journal of Marine Science, 64: 1414–1422. A total of 199 female yellow European eels (Anguilla anguilla), 21.6–66.2 cm long and 3–14 years old, was collected by electro-fishing from six lakes in the River Havel system (Germany) in spring 2001. The condition and the growth rate, estimated by otolith increments, varied between eels within single lakes and between lakes. Fulton's condition factor ranged from 0.10 to 0.24 and the gross energy content varied between 4.3 and 15.3 MJ kg−1. There were no significant differences in mean condition factor (0.16–0.18) or gross energy content (6.5–9.3 MJ kg−1) between lakes. Fastest growth was in Lake Blankensee (mean 5.3 cm year−1), and the slowest in Lake Sacrow (mean 4.0 cm year−1). For all lakes combined, the overall mean annual increment was estimated to be 4.5 cm year−1. The biggest annual increment on the otoliths was generally laid down during the first and second years in fresh water, when the growth rate was 6.1–8.5 cm year−1. Then, in the subsequent 12 years, the annual increment remained almost constant or decreased slightly (with lake-dependent values of between 1.6 and 6.8 cm year−1). In the River Havel system, the time between stocking of the lakes with glass eels and the recapture of eels at 45 cm body length was 7–10 years. The physiologically possible maximum length (L∞ values) of eels lay in the range 50–130 cm. In comparison with previous investigations (between the 1950s and the 1970s), the only difference observed was a trend towards slower growth.


1988 ◽  
Vol 140 (1) ◽  
pp. 313-324 ◽  
Author(s):  
J. D. ALTRINGHAM ◽  
I. A. JOHNSTON

A nerve-muscle preparation from the sculpin Myoxocephalus scorpius was used to study the membrane response of fast and slow muscle fibres to stimulation of the spinal nerves. There was no significant difference between resting potential in fast (−81.9mV) and slow fibres (−80.8mV). Fast fibres responded to a suprathreshold stimulus in the spinal nerve with an action potential. Overshoots of up to +32 mV were recorded. Both junction potentials and overshooting action potentials were observed in the slow fibres. The twitch/tetanus characteristics of myotomal muscle were investigated using isolated bundles of ‘live’ fast and slow fibres. Both fibre types responded to a single stimulus with a mechanical twitch. Fused tetani were obtained at around 50Hz in fast fibres and 20 Hz in slow fibres. In the slow fibres, tetanic tension increased with frequency up to around 50Hz. At frequencies giving maximum tetanic tension, the twitch/tetanus ratio was 0.70 for fast fibres and 0.29 for slow ones. These results are discussed with reference to the polyneuronal/multiterminal innervation pattern of the myotomal muscle in teleost fish and its role in locomotion.


1988 ◽  
Vol 140 (1) ◽  
pp. 187-197 ◽  
Author(s):  
N. A. CURTIN ◽  
R. C. WOLEDGE

The relationship between force and velocity of shortening and between power and velocity were examined for myotomal muscle fibre bundles from the dogfish. The maximum velocity of shortening, mean value 4.8 ± 0.2 μms−1 half sarcomere−1 (±S.E.M., N = 13), was determined by the ‘slack step’ method (Edman, 1979) and was found to be independent of fish length. The force-velocity relationship was hyperbolic, except at the high-force end where the observations were below the hyperbola fitted to the rest of the data. The maximum power output was 91 ± 14 W kg−1 wet mass (±S.E.M., N = 7) at a velocity of shortening of 1.3 ± 0.13μms−1 halfsarcomere−1 (±S.E.M., N = 7). This power output is considerably higher than that previously reported for skinned fibres (Bone et al. 1986). Correspondingly the force-velocity relationship is less curved for intact fibres than for skinned fibres. The maximum swimming speed (normalized for fish length) predicted from the observed power output of the muscle fibres decreased with increasing fish size; it ranged from 12.9 to 7.8 fish lengths s−1 for fish 0155–0.645m in length.


1996 ◽  
Vol 48 (4) ◽  
pp. 633-642 ◽  
Author(s):  
W. Russell Poole ◽  
J. D. Reynolds

2004 ◽  
pp. 123-148
Author(s):  
B. G. Kapoor ◽  
Bhavna Khanna

1990 ◽  
Vol 47 (10) ◽  
pp. 1888-1897 ◽  
Author(s):  
Matti Verta

A small polyhumic lake inhabited by northern pike (Esox lucius), burbot (Lota lota), perch (Perca fluviatilis), roach (Rutilus rutilus), and eel (Anguilla anguilla) was fished intensively during spring 1984 and 1985 to lower the high mercury levels in the top predator, northern pike. A total catch of 29.5 kg∙ha−1 (74% roach) was removed which represented about 50% of the total fish biomass. Mercury concentrations in burbot, large pike, and small roach had decreased by 1987 and 1988, but increased in young pike and some perch. Northern pike had the clearest increase in growth rate, while that of perch and roach levelled off within 3 yr at the prefishing level. Only a small increase in growth rate of burbot occurred. The yearly accumulation of mercury in northern pike remained constant, and the decrease in [Hg] was apparently due to growth dilution. The decrease in [Hg] of burbot and roach is explained by a switch to a diet with lower [Hg] or a decrease in water methylmercury concentrations. The amount of methylmercury removed from the lake by fishing was equivalent to several years of calculated mercury methylation and accumulation in the fish. Overfishing may be a feasible means of lowering methylmercury levels in this type of oligotrophic lake.


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