Girardinus metallicus Fish Control and Anesthetized (image) California Polytechnic State University Share Print E-Mail Caption The same male Girardinus metallicus fish photographed in control water treatment (top) and following anesthetization with the commonly used anesthetic MS222 (bottom), illustrating the darkening under anesthesia. Credit Kolluru lab Usage Restrictions Permission of publisher required. Share Print E-Mail 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.