Spirogyra (image) Cell Press Share Print E-Mail Caption This photo shows green algae Spirogyra, which reproduce sexually by a process known as conjugation. Credit Gert Hansen, SCCAP, Copenhagen Usage Restrictions Credit 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.