Muscular and Energetic Aspects of Fish Swimming

Abstract

Adult fish of different species vary in length from 20 mm to around 12 m; they are designs operating over a very wide Reynolds number range. The upper limit is uncertain, since maximum speeds of the largest fishes have not been measured accurately, but it seems probable that these are able to operate at Reynolds numbers well above 107. Individual species do not span such a wide range, but the difference between cruising speeds which can be maintained for periods of hours at least, and burst speeds which can only be achieved for a few minutes, means that many fish whose swimming has been studied in the cruise condition exceed 2 {\texttimes} 106 during bursts.