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Fig. 3. Atlantic salmon (Salmo salar L.) reared under conditions of
ambient photoperiod (closed circles, solid line; combined cages 1 and 2) or
continuous lighting from 1 November 2000 to 18 June 2001 (open circles, broken
line; combined cages 3 and 4). (A) The relationship between the number of
fibres and the total cross-sectional area (TCA) of fast myotomal muscle at the
level of the first dorsal fin ray. The arrows join common sample points. (B)
The relationship between the densities of fast muscle fibres (fibres
mm-2 cross-sectional area) and the growth period in seawater. The
results are means ± S.E.M. The number of fish sampled from
each cage is shown in Table
2.