Fig. 1. Linear dimensions determined on the skeletal elements of the feeding apparatus in Clarias gariepinus. (A) Dorsal view of the lower jaw, illustrating the measurement of lower jaw length and angle. (B) Lateral view of the lower jaw, illustrating the measurement of lower jaw length, coronoid height (ch), the in-lever for jaw closing (close) and the in-lever for jaw opening (open). (C) Ventral view of the hyoid, illustrating the measurement of hyoid length and angle. (D) Lateral view of the hyoid, illustrating the measurement of hyoid length and depth. (E) Dorsal view on the cleithrum, illustrating the measurement of cleithrum symhysis length (s.i.) and cleithrum angle. (F) Medial view of the operculum, illustrating the measurement of operculum length. Pictures are not to scale.