<I>Spirogyra</I> (IMAGE) Cell Press 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. 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.