Fig. 1. Effect of body mass on (A) oxygen consumption rates (µmol O₂ g^-1 h^-1; 5°C) and (B) citrate synthase activity (units g^-1; 20°C) of cephalopod molluscs. The relationships drawn are for families Loliginidae (filled blue triangles), Ommastrephidae (open blue triangles), Gonatidae (blue crosses), Octopodidae (open brown inverted triangles), Histioteuthidae (brown circles), Cranchidae (open brown circles), Bolitaenidae (black squares), Vampyroteuthidae (white squares). The scaling coefficients for oxygen consumption rates of Loliginid squids are significantly different from benthic Octodidae (ANCOVA, P<0.05), and others, and the s.e.m. does not include quarter power (-0.25). Regression equations are presented in Table 1 while sources of data can be found in supplementary material Tables S1-S4.