Guinardia blavyanus syn Dactyliosolen blavyanus, Rhizosolenia blavyanus
This multi-named species is identified by the horozontal girdle bands, which are just visible near the bottom of the photo on the left. They are difficult to pick out with LM. The cells are straight, 6-38µm in diameter. They can be solitary or in small chains. They may cause heavy blooms. They are found in temperate to warm waters. This sample came from the Phoenix area of Andaman Islands, Bay of Bengal.