Effects on lateral expansion during suction feeding
The enlarged jaw muscles tightly cover the suspensoria, which are (especially in the hard-biting species) firmly connected to the neurocranium. Consequently, the jaw adductor hypertrophy could interfere with the lateral expansion of the buccal cavity occurring during suction generation, in which the suspensoria are abducted (i.e. rotated away from the medial body axis). This suspensorium-abduction can be hindered by either visco-elastic deformation of the jaw muscles or by the strongly interdigitated connection with the neurocranium. More information and results can be found in: Van Wassenbergh, S., Herrel, A., Adriaens, D. and Aerts, P. (2004). Effects of jaw adductor hypertrophy on buccal expansions during feeding of air breathing catfishes (Teleostei, Clariidae). Zoomorphology 123, 81-93 (full text PDF) (Full text HTML at SpringerLink)
Illustration of the jaw muscles (red), the suspensorium (blue) and a detailed view on the suspensorium-neurocranium connection (yellow frame) in Clariallabes longicauda