Phytoplankton: Several species may be applied, including Tetraselmis chuii - the most likely one you'll have in a culture - as well as T. subcordiformis and T. tetrathele. A motile green algae. Cells are ~10µm wide and ~13µm long with 4 flagella at the anterior end of the cell. Inferior fatty-acid content when compared to other micro-algaes, but may be useful as a direct feed for organisms too small to accept rotifers. Tetraselmis may also have some anti-bacterial or immune-boosting properties.