Meeting Abstract

68.5  Tuesday, Jan. 6  The Role of Mouth Shape on the Hydrodynamics of Suction Feeding in Fishes SANFORD , C. P. J.*; DAY, S. ; KONOW, N.; Hofstra University, Hempstead NY; Rochester Institute of Technology, Rochester NY; Johns Hopkins Medical Institute, Baltimore MD christopher.p.sanford@hofstra.edu

One of the key events in the evolution of fishes was the decoupling of the maxillary bone from the skull resulting in a highly mobile maxilla. It has been suggested that this maxillary mobility resulted in increased suction feeding performance by allowing the flow of water entering the mouth to be more anteriorly directed. Using DPIV the hydrodynamics of suction feeding in the bowfin (Amia) was examined prior to, and following maxillary immobilization in an effort to empirically test this assertion. We show that when the maxilla is immobilized (i.e. the mouth opening is wedge shaped rather than circular) the strike is initiated when the prey is closer to the predator. Also, maximum suction pressure is less, and occurred earlier following maxillary immobilization. Finally, Maximum gape is larger and there is an increase in duration of significant fluid flow when the maxilla is immobilized. However, there is no difference in the area of significant fluid flow or fluid speed in front of the mouth. This work suggests that there are important hydrodynamic consequences of mouth shape that can be compensated for by changes in behavior. Supported by the NSF (IOS#0444891, DBI#0420440).