Male and Female Swordtail Fish (IMAGE) University of Exeter Caption Male and female green swordtail fish. Credit Copyright Craig Walling, University of Exeter Usage Restrictions Only to be used in conjunction with this story. Copyright must be credited to Dr. Craig Walling, University of Exeter. 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.