The world's largest omnivore is a fish (IMAGE) Australian Institute of Marine Science Caption Researchers discovered whale sharks ate plants as well as krill. Credit Photo by Andre Rerekura, Australian Institute of Marine Science Usage Restrictions Please credit image License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.