Changes in body size affect the biomechanics and behavior of teleost fishes


Meeting Abstract

8-1  Friday, Jan. 4 08:00 – 08:15  Changes in body size affect the biomechanics and behavior of teleost fishes GIBB, AC*; MINICOZZI, MR; Northern Arizona University; Northern Arizona University alice.gibb@nau.edu http://jan.ucc.nau.edu/acg/

Thousands of studies have examined how the biomechanical and physiological underpinnings of movement are influenced by body size in tetrapods, particularly in terrestrial mammals. Yet, very few studies have considered how changes in body proportions (length vs. area vs. volume) and established allometric parameters for muscle kinetics dictate what behaviors can be employed and how habitats can be used by teleost fishes, the most numerous vertebrates on the planet. We note that several hallmark teleost behaviors may only be possible for individuals of certain sizes. For example, a very rapid change in buccal volume is required to produce effective suction feeding, but the muscular forces required to produce this behavior may not keep pace with increased buccal volume in large fishes. Similarly, the time to complete the “preparatory” stage of a fast-start (or C-bend) will become greater as fish grow larger, with the result that a large fish will remain in a vulnerable position for an extended period of time. In addition, because fishes live in a microgravity environment, inertial effects of increased body mass are often completely ignored. However, simple predictions based on fundamental scaling parameters yield size-based expectations for key teleost behaviors: either large fishes cannot perform these key behaviors and have eliminated them from their behavioral repertoires, or they have developed physiological or morphological “workarounds” to circumvent the problems inherent to changes in body size. Thus, best practices for fish ecologists, biomechanists, behaviorists, and physiologists are studies that incorporate predictions based on established scaling relationships for morphological/physiological parameters and test the assumptions of geometric similarity (isometric scaling) in teleost fishes.

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