Inland Silverside (IMAGE) Smithsonian Caption A reflected inland silverside (Menidia beryllina) performs "aquatic surface respiration" in an aquarium. When threatened with low oxygen, fish often swim to the surface, where oxygen is more abundant but predators can more easily spot them. Credit Smithsonian Environmental Research Center Usage Restrictions None License Licensed 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.