S6.1-2 Sunday, Jan. 5 09:00 Stability and change in the development of movement systems: Meeting short-term functional demands of the early life history and long-term needs for growth and maturation to the adult form. HALE, M. E. ; Univ. of Chicago email@example.com
Most fish species experience tremendous change in morphology and physiology through development. In addition to undergoing increase in size, their body shape and the organization of functional systems are often transformed. Through this period of growth and maturation, fishes must remain functional. As physiological and biomechanical demands shift through development with changes in predation pressures, food resources, Reynolds number and other factors, developmental processes must play the dual roles of ultimately achieving the adult form while generating intermediate stages that are adapted to the environment for each life history period. One example of developmental change in the morphology and function is the pectoral fin system. The structure and role of larval and adult zebrafish pectoral fins are strikingly different. In adults, the fins are generally actuated arrhythmically and serve roles in maneuvering and stability. In larval zebrafish, pectoral fins beat rhythmically and are coordinated with axial bending. Experimental work and computational modeling have shown that the larval fins do not generate propulsive force but instead are used to direct fluid flow near the body and augment cutaneous respiration. The morphology and movement of the larval fins suggest specific adaptations to this function. The pectoral fins of larvae and adults have distinct adaptive peaks of morphology and function, requires that there is a period of dramatic change in this system as an animal transitions between these organizations. Here I examine how fishes accomplish changes between functionally stable organizations in the pectoral fin system and in other comparative examples and I discuss implications for how change in function is navigated more broadly.