Other Animal Sciences Commons^™

Skeletal Stiffening In An Amphibious Fish Out Of Water Is A Response To Increased Body Weight, Andy J. Turko, Dietmar KüLtz, Douglas S. Fudge, Roger P. Croll, Frank M. Smith, Matthew R. Stoyek, Patricia A. Wright

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Terrestrial animals must support their bodies against gravity, while aquatic animals are effectively weightless because of buoyant support from water. Given this evolutionary history of minimal gravitational loading of fishes in water, it has been hypothesized that weight-responsive musculoskeletal systems evolved during the tetrapod invasion of land and are thus absent in fishes. Amphibious fishes, however, experience increased effective weight when out of water – are these fishes responsive to gravitational loading? Contrary to the tetrapod-origin hypothesis, we found that terrestrial acclimation reversibly increased gill arch stiffness (∼60% increase) in the amphibious fish Kryptolebias marmoratus when loaded normally by gravity, …