Research with ectothermic organisms has demonstrated that temperature is positively correlated with an individual’s functional power output.  This study investigates the effect of temperature on energetic input of the bluegill sunfish Lepomis macrochirus via prey capture kinematics.  Feeding sequences for two treatments of four sunfish were filmed at three temperatures (18°, 24°, 30°C), with one treatment (A) experiencing an increasing range of temperatures, and the other (B) a decreasing temperature range.  Directional temperatures affected prey capture kinematics.  The time required to achieve maximum lower jaw depression and maximum gape, as well as the duration of maximum gape, time to close the mouth (from the point of maximum gape) and the total bite duration, increased as water temperature decreased.  In addition, both the time to maximum gape and maximum lower jaw depression were longer at 18°C for individuals in treatment A, as compared with treatment B.  These results indicate that water temperature can bias the results of feeding studies employing kinematics that do not control for its effects, as wellxa. as those that make comparisons across such studies which utilize different temperatures and ta

Feeding kinematics of juvenile bluegill sunfish, Lepomis macrochirus
Kyle R. Mara

The feeding kinematics and mechanics have been investigated for numerous adult fishes. However, there is a paucity of work on the feeding kinematics and mechanics of juvenile fishes. This study focuses on the feeding mechanics of juvenile bluegill, Lepomis macrochirus. Standard kinematic variables of feeding will be measured and used to draw conclusions about the effect of size on the feeding biology of L. macrochirus. Data will be gathered from juvenile bluegill ranging in size from 22 to 35 mm total length. This data will then be compared to data obtained from studies focusing on adult bluegill feeding kinematics. The goal of this study is to investigate the effect of animal size on the feeding kinematics. It is expected that the smaller an organism is the faster its feeding kinematics will be. In preliminary work performed on 4 individuals, it was discovered that juveniles have shorter bite duration, open their mouths more quickly, and close their mouths more quickly than adult L. macrochirus do. The causes of these observed differences have yet to be determined. However, muscle contraction rates are one possible cause. More extensive research studies of feeding kinematics throughout ontogeny are needed.