Fig. 3. A double logarithmic plot of the number of slow muscle fibres per myotomal cross-section at 0.7 FL and M_b in Arctic charr from Thingvallavatn. The data points represent dwarf benthic morphs (open circles), planktivorous morphs (open triangles, large benthic morphs (filled circles) and piscivorous morphs (filled triangles). A first order polynomial was fitted to the data with the following equation: log₁₀(slow fibre number)=log₁₀2.98±0.027+0.45±0.114(log₁₀FL) (r²=0.91; d.f. 112; ANOVA; F_1,111=1134.4; P<0.0001).