Fig. 7. Hypertrophy of `first wave' somitic red fibres in Danube bleak (Cc) reared at rising temperatures (12-16°C versus 18-20°C) and pearlfish (Rf) reared at constant temperatures (12°C versus 16°C). Size (cross-sectional area) means of defined numbers of largest fibres per epaxial quadrant (Cc: N=25, Rf: N=40; for rationale see Materials and methods, Data analysis) within developmental stages as defined in Table 1 (40som, 40 somite embryo; hatch, newly hatched free embryo; swup, free embryo at onset of free swimming; feed, larva after first uptake of exogeneous food; larv1, Cc larvae of stage 5, Rf larvae at 11 mm body length; larv2, Cc larvae of stage 6, Rflarvae at 12.5 mm body length). Values are means ± 1 S.D.