Discussion
Guitarfish feeding mechanism
Prey capture, bite manipulation and suction transport
behaviors in the Atlantic guitarfish are characterized by a
common relative pattern of kinematic events. However, many
differences were found in the specific timing of the kinematic
events among these behaviors. Most of these differences are due
to the longer duration of capture than manipulation or transport
behaviors, as shown by the delayed onset of kinematic and
motor events following the start of lower jaw depression. In
contrast, the onset and duration of motor activity in several of
the cranial muscles is modulated among the feeding behaviors.
A novel compression transport mechanism was found that is
strikingly different in both kinematic and motor activity from
the other behaviors and has not previously been described in
any elasmobranch. A model of jaw mechanics for the guitarfish
based on anatomy, kinematics and motor activity during
feeding will provide a basis for interpreting the feeding
mechanism in batoids. The entire feeding event, encompassing
prey capture, manipulation, suction transport and compression
transport, is extremely long with a mean duration of 16.24 s
(range 3.38–54.87 s, N=5). Note that a brief interval (range
50–150 ms) of kinematic and motor inactivity takes place
between each of the four behaviors.