Sam Van Wassenbergh

left:  Picture illustrating the large increase in size that takes place during the life of the catfish Clarias gariepinus.  The arrow indicates the smallest individual used in our study.

Although scaling relationships on aquatic feeding kinematics have been studied previously, the size-related effects of kinematics on performance (displacing the prey towards the mouth) and the biomechanical causes of the observed changes in suction feeding kinematics (decreasing speed of cranial expansion with growth) remain unclear.  As our study species (Clarias gariepinus, Clariallabes longicauda, Gymnallabes typus and Channallabes apus) differ considerably in adult cranial size, a better knowledge on the biomechanical consequences of size on the suction feeding process in Clariidae is more than welcome.  In this part of the study, we analyzed prey capture kinematics in an ontogenetic series of the African catfish (Clarias gariepinus), a species that can grow up to 1.5 m in total length.  By modelling the observed expanding head of C. gariepinus as a series of expanding hollow elliptical cylinders, spatio-temporal patterns of water flow, buccal pressure and power requirement for the expansive phase of prey capture were calculated.  Currently, scaling of the contractile properties of the muscles used during feeding are analysed in collaboration with Dr. Rob James (Coventry University, UK).  More information and results are available in the following  papers:

Van Wassenbergh, S., A. Herrel, R.S. James and P. Aerts (2007) Scaling of contractile properties of catfish feeding muscles. J. Exp. Biol. 210: 1183-1193. (full text PDF)

Van Wassenbergh, S., Aerts, P. and Herrel, A. (2006). Scaling of suction feeding performance in the catfish Clarias gariepinus. Physiol. Biochem. Zool. 79, 43-56.(full text PDF)

Herrel, A., Van Wassenbergh, S., Wouters, S., Adriaens, D. and Aerts, P. (2005). A functional morphological approach to the scaling of the feeding system in the African catfish, Clarias gariepinus. J. Exp. Biol. 208, 2091-2102. (full text PDF)

Van Wassenbergh, S., Aerts, P. and Herrel, A. (2005). Scaling of suction-feeding kinematics and dynamics in the African catfish, Clarias gariepinus. J. Exp. Biol. 208, 2103-2114 (full text PDF)