Actinoptychus are centric diatoms, approximately 20-150μm in diameter. They are found solitary or in loose groups. Their valves are divided into six sections alternating elevated and depressed.
Actinoptychus are widely distributed.
SoundToxins, a diverse partnership of Washington state shellfish and finfish growers, environmental learning centers, Native tribes, and Puget Sound volunteers, is a monitoring program designed to provide early warning of harmful algal blooms and Vibrio parahaemolyticus events in order to minimize both human health risks and economic losses to Puget Sound fisheries.