Threatened species of Silicoflagellata

The silicoflagellates are single-celled plankton that have a delicate siliceous skeleton made up of tubular rod-shaped elements. The taxonomy is unclear with different treatments according to author. Some place the silicoflagellates in the Chrysophyta (golden algae), others in the larger grouping of Heterokontophyta, and yet others in the Protista (recognizing their single cell nature).