Abstract: | The sterols of the hydroid, Dynamena pumila (Sertulariidae) have been analysed for the first time. Results from TLC, GLC, mass spectrometry and NMR have led to the determination of the structure of 16 steroids, the main being cholesterol (37%). A series of Δ5 22 C26, C27, C28 C29 sterols, and the corresponding stanols and fucostanol, have also been identified. |