Food capture kinematics of the suction feeding horn shark, Heterodontus francisci

The goal of this study was to examine the feeding kinematics of the horn sh ark, Heterodontus francisci, a member of the most basal clade of galeomorph sharks, the Heterodontiformes. The accessibility of the food was manipulat ed to determine if the horn shark modulated capture. Three different method s of presenting food were used to mimic the different positions of prey ite ms found in the natural diet of the horn shark. Food was presented unattach ed to the substrate, securely attached, or fitted snugly in a tube. Using h igh-speed video kinematic analysis, capture events were examined. Heterodon tus francisci uses inertial suction facilitated by rapid mandible depressio n and labial cartilage protrusion to capture food. The horn shark conforms to a capture kinematic profile characteristic of both basal and derived ine rtial suction feeding sharks. Unusual post-capture behaviors include body l everaging, use of the mouth to form a seal over food, and chisel-like palat oquadrate protrusion. When presented with food of different accessibility, Heterodontus francisci used one consistent kinematic pattern for capture th at was not modulated. Only post-capture behaviors varied according to food accessibility.