Sterols of<i>Chaetoceros</i> and<i>Skeletonema</i>

Abstract

Abstract Dietary sterol is required by the oyster for growth, and sterol is believed to be obtained primarily from dietary phytoplankton. Seven isolates of Chaetoceros and one of Skeletonema , which are of potential use as oyster food, were analyzed for sterol composition using gas chromatography, high‐performance liquid chromatography and gas chromatography/mass spectrometry. Skeletonema and five isolates of Chaetoceros contained cholesterol as their major sterol. Two other isolates of Chaetoceros also contained cholesterol, but 24‐methylenecholesterol was the principal sterol. Cholesterol has rarely been reported as the major sterol from phytoplankton. In view of the widespread occurrence of Skeletonema and Chaetoceros in the marine environment, these algae could be an important source of the oyster's cholesterol.