Scaling effects on the neuromuscular system,twitch kinetics and morphometrics of the cod,Gadus morhua |
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| Authors: | Stephen D Archer John D Altringham Ian A Johnston |
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| Institution: | 1. Gatty Marine Laboratory, Department of Biology and Preclinical Medicine , St. Andrews University , St. Andrews, Fife, KY16 8LB;2. Dept of Pure and Applied Biology , The University , Leeds, LS2 9JT |
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| Abstract: | Size related changes in muscle twitch kinetics, morphometrics and innervation have been examined in cod, Gadus morhua. Fish size ranged from 9 cm to 45 cm in total length (L). Twitch contraction time (time to 90% relaxation), scaled in proportion to L0.29. Scaling of morphometric parameters was essentially geometric. Mean cross‐sectional area and weight of the myotomal muscle scaled in proportion to L2.05 and L3.08 respectively. These results are discussed in the light of alterations in length specific swimming performance and kinematics as fish grow. During growth, the number of endplates terminating on each fast fibre increased, from around 10 on fibres 2 mm in length (～10 cm fish) to 20 on 10 mm fibres (—40 cm fish). However, mean spacing between endplates increased from around 0.25 mm to 0.50 mm. The functional significance of polyneuronal innervation in teleost fast muscle fibres is discussed. |
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| Keywords: | Contraction endplates fish muscle neuromuscular system scaling |
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