28th Annual Student Research Conference
Bigger, Stronger but Not Faster: jaw biomechanics through ontogeny of the great sculpin, Myoxocephalus polyacanthocephalus
Anna D. Conrades* and Nina L. Finley
Dr. Timothy D. Walston and Dr. Nicholas J. Gidmark (University of Washington), Faculty Mentors
Musculoskeletal variation in jaw anatomy and kinematics throughout ontogeny was examined in the suction-feeding great sculpin, Myoxocephalus polyacanthocephalus. The intrinsic length-tension properties of muscle allow maximum jaw force (P0) production at intermediate muscle lengths (L0), with declining force above and below L0. As a suction-feeding fish grows, the volume it engulfs scales with length3. However, jaw-closing muscle force scales with length2 (force ∝ muscle cross-sectional area ∝ length2). The difference in scaling rate results in a muscle force deficit as a fish grows. Results show great sculpin increase jaw leverage to maximize force at longer lengths, countering the force deficit, yet throughout ontogeny great sculpin experience a constant available muscle strain. With increased length, fish use a wider range of the available muscle strain, deviating from L0. Therefore, in addition to an increasing muscle force deficit, larger great sculpin experience declining jaw-closing forces due to the limitations of jaw-closing muscle.
Keywords: Myoxocephalus polyacanthocephalus, ontogeny, scaling, length-tension, lever ratio, rictalis muscle, sonometric and force transducers, suction feeding
Topic(s):Biology
Physics
Presentation Type: Poster
Session: 3-2
Location: GEO-SUB
Time: 3:30