Fast-start

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Fast-start er korte pludselige accelerationer hos fisk.[1] Fast starts benyttes ved predator-prey interaktioner. Fast starts inddeles i c-start hvor kroppen bøjes i et c og s-start hvor kroppen bøjes i et s. Fast starts sker hurtigere end det menneskelige øje kan registrere og reaktioner på 6 ms er målt hos for eksempel zebrafisken.

Via mekanisk modellering er det blevet målt at nogle fisk under fast-start accelerationen, accelererer med op til 40 m/s^2 eller ca. 4 G. [2]

Kilder/referencer[redigér | redigér wikikode]

  1. ^ Comp Biochem Physiol A Mol Integr Physiol. 2001 Dec;131(1):31-40, Biomechanics of fast-start swimming in fish Citat: "...Fast-starts are high acceleration manoeuvres used by fish...Fast-start escape responses can be initiated by a nervous reflex mediated by a Mauthner neurone and result in the simultaneous activation of muscle along one side of the body...."
  2. ^ iopscience.iop.org: A fast-starting mechanical fish that accelerates at 40 m s^−2 Citat: "...Efficiency is estimated based on the transfer of energy from elastic potential to kinetic swimming energy. The fish beam placed in the 23 cm curvature has about 3.8 J of energy, and an error of 1 cm in either direction does not change the stored energy dramatically: a curvature of 22 cm corresponds to 3.5 J of stored energy and a curvature of 24 cm, to 4.2 J. When released, the model accelerates to a mean velocity of around 1.2 m s−1. The energy transferred to kinetic energy is thus approximately 0.4 J, and the efficiency is approximately 10%. The fast-start efficiency for live fish, as noted previously, is in the range of 16–39%..."

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