Gape-specific bite force and prey-size specific predator performance in the snail-eating black carp
- Brown University, Providence, RI, USA
- The University of California at Davis, Davis, CA, USA
*Author for correspondence: Nicholas J. Gidmark | Published article | Press release
In this study we used X-ray Reconstruction of Moving Morphology (XROMM) to examine biting performance in a snail-eating carp species, the black carp (Mylopharyngodon piceus). Instead of using its oral jaws for crushing, black carp use the pharyngeal jaw apparatus, in the back of the throat (Figure 1). Using food items of known size and strength (Figure 2), we showed prey-size specific performance of the carp (Figure 3). The strongest items were only crushable at intermediate length, whereas weaker food items were crushable at a broader range of sizes. Next, we used XROMM to measure jaw and skull positions during in vivo biting on these same food items. From these XROMM animations, we measured muscle fiber lengths. Finally, we conducted in situ tests where we electrically stimulated the jaw-closing muscles and directly measured muscle force while using XROMM to measure bone posture (and, therefore, muscle length, Figure 4). By combining these three data streams (prey feeding trials, XROMM recordings of in vivo biting, and in situ recordings of maximum bite force, Figure 5), we demonstrated that: 1) Crushing performance in black carp is prey-size specific; 2) Prey size influences the instantaneous length of the jaw-closing muscle in black carp; and 3) bite force changes as a result of muscle length change, and this force contributes directly to bite performance. These results demonstrate how fundamental performance metrics of muscle fibers can function to limit performance on the organismal scale in black carp.
Gidmark, N.J., N. Konow, E. LoPresti, and E.L. Brainerd. (2013). Bite force is limited by the force-length relationship of skeletal muscle in black carp, Mylopharyngodon piceus. Biology Letters, 9:20121181. Published article. Press release.