Photo of the Week: Run, Fish, Run!

Why have an amphibious fish run on a treadmill? Not for exercise or even a viral YouTube video. In order to test how oxygen impacts certain animals, scientists at Scripps Institution of Oceanography at UC San Diego took measurements of a Japanese mudskipper (Periophthalmus modestus, shown here inside Scripps’s Scholander Hall) on a specially designed treadmill. The project, featured as the cover story of the August edition of Integrative and Comparative Biology, tested the treadmill-running animal to model how a peak in oxygen levels in the Paleozoic Era (400-250 million years ago) may have paved the way for animals to emerge from the sea and proliferate on land (an idea that that was confirmed through the study). Authors include Scripps’s Corey Jew, Nick Wegner, Yuzo Yanagitsuru, Martín Tresguerres, and Jeff Graham, a longtime and beloved Scripps researcher who set the stage for the study before he passed away in 2011. “(Graham’s) guidance and legacy will continue to influence many,” the authors note in their report. Image courtesy of Integrative and Comparative Biology