SUCTION FEEDING STRATEGIES OF TWO SPECIES OF MEDITERRANEAN SERRANIDAE (SERRANUS CABRILLA AND SERRANUS SCRIBA) by C. VILADIU1, P. VANDEWALLE2, J.W.M. OSSE3 and A. CASINOS1,* (1 Departament de Biologia Animal (Vertebrats), Universitat de Barcelona, Diagonal 645, 08028 Barcelona, Spain; 2
THE EXPANSION APPARATUS IN FISH HEADS, A 3-D KINETIC DEDUCTION by J. DE VISSER and C.D.N. BAREL* (Institute of Evolutionary and Ecological Sciences, Leiden University, Postbus 9516, 2300 RA Leiden, The Netherlands) ABSTRACT Among teleost fishes, suction feeding is the most frequent mode of
jaw adduction. In contrast, a larger jaw closing lever ratio indicates that the efficient translation of force by the muscles to the biting or crushing surface occurs at the expense of jaw closing speed. Crushing and biting species have higher jaw closing lever ratios than do suction-feeding species
opercular cavities serve large volume changes for suction feeding. Protruding types of taste buds and oligovillous epithelial cells may well serve mechanoreceptive functions required for steering the process. Otherwise, specialized mechanoreceptors have not been recognized. Mucous cells producing low
The present study examined the kinematic patterns of initial food uptake, food transport, pharyngeal packing and swallowing in the common musk turtle Sternotherus odoratus. These data are supplemented by morphological descriptions of the skull and the hyolingual complex. Although the hyoid is mainly cartilaginous, S. odoratus still use exclusively hydrodynamic mechanisms in prey capture and prey transport. The tongue is relatively small, with weakly developed intrinsic musculature. We propose that the elasticity of the hypoglossum and the hyoid body impacts the capability of S. odoratus to suction feed, but allows these turtles to effectively re-position the food items within the oropharyngeal cavity during transport, manipulation and pharyngeal packing. We standardised conditions in all feeding events by using food items of the same consistence and size, and by always offering the food at the same position at the bottom of the aquarium. Nonetheless, the measured kinematic values varied considerably. The duration of prey capture and prey transport cycles were relatively long in S. odoratus compared to other freshwater turtles studied so far. The initiation of hyoid retraction relative to the onset of jaw opening can be modulated not only in prey capture but also in prey transport cycles. In the common musk turtle, the jaw and hyoid movements apparently have a low level of integration.
studies in percid and cyprinid fishes were carried out, soon followed by the development of physical and hydrodynamic models of suction feeding in fish and fish larvae (with Muller, van Leeuwen, Drost). This research was inspired by the idea that 40 million years of fish evolution must have produced a
other apparatuses, especially the expansion apparatus (EA) and outer head shape (OHS, part of the locomotory apparatus). It is demonstrated that the suction feeding and biting can be combined to a certain extent and at certain costs. Increase in streamline is inversely related to active head expansion
hydrodynamic model of suction feeding of a 6.5 mm carp larva, calculated from the streamlines and fluid particle pathlines observed. From this model we also have calculated the accelerations of the water near the mouth aperture (which reach 800 m/s2) and the path lines of actively accelerating fluid particles
-up, such that more detailed and com- plete data of the flow in the fish mouth and opercular cavities may be obtained. KEY WORDS: NMR imaging, flow visualisation, Cyprinus carpio. INTRODUCTION During breathing and suction feeding fish expand and compress their head, generating water flow through their
on a film recording (this is the verification process), one could come to the hasty conclusion that wide jaw depression during suction feeding in Astatolilapia elegans indeed is caused via the opercular four bar mouth opening system. (This impression may even be reinforced when one takes into account