Fig. 4. The mass-specific net cost of transport (COT_net) for chub mackerel at 18 °C (open squares) and 24 °C (filled squares) as a function of fish fork length (FL). The lines are the best-fitting equations: COT_net=-253FL+8387, r²=0.72, N=12, P<0.001, at 18 °C (dashed line); COT_net=-31383logFL+46734, r²=0.48, N=12, P<0.02, at 24 °C (solid line). At a given fish size, COT_net was greater at 24 than at 18 °C (ANCOVA; P=0.02), even if the highest point for the 14.0 cm FL mackerel at 24 °C is omitted. Values are means ± S.E.M.