University of Washington professor, Kristi Morgansen, has been working on these robots for 5 years. With aspirations to someday track large herds of animals and map the bottom of the ocean, communicating wirelessly while they do it. They may look small but are actually about the size of a 10 pound salmon.
A little more information
if you are interested. There's a picture of the actual robot and the creator, plus some facts about it.