a microsopic dinoflagellate parasite of freshwater fish, which causes "velvet".
A disease in marine fish which causes the affected individual to rub against rockwork.
This is a dinoflagellate organism which is responsible for Velvet Disease in freshwater fishes.
Oödinium (also known as Piscinoodinium) is a genus of microscopic parasitic dinoflagellates. They live off salt and fresh water fish, causing a type of fish velvet disease (also called gold dust disease).