This study looks at how koi move through water - with the end result of trying to figure out how to make underwater robots. If you are curious about koi and science, you will like this study.
"With the rapid development of science and technology, advanced underwater robots have extensively promoted human beings’ abilities to understand, explore, and preserve the oceans. Understanding the mechanism of fish movement has essential scientific and practical significance for advancing underwater robotics technology... The research results can significantly help the designing, developing, and optimizing modern underwater robots."