Fig. 4. Graphical representation of the scaling of skeletal dimensions of the cleithrum in Clarias gariepinus. The mass (A) and length (B) of the cleithrum both scale with significant positive allometry (slope different from 3 and 1, respectively; see Table 2). The angle between the two halves of the cleithrum (C) scales with marginal but significant negative allometry (Table 2). The broken lines represent the expected slope under a model of geometric similarity (mass=3, length=1, angle=0). (D) A series of representative cleithra, illustrating the difference in shape in different individuals. The different filled symbols on the graphs correspond to the respective cleithra illustrated. Scale bar, 50 mm.