Gymnodinium catenatum (jim-know-din-ee-um) is a chain forming motile species associated with the production of toxins. This image of the ventral surface of several cells shows the equatorial groove or girdle and longitudinal groove or cingulum. Flagella can also be seen. Because of the toxicity, correct identification is important and needs expert input, which can be obtained from other sites such as IOC Harmful Algal Bloom Program.
Differential interference microscopy.
data on this strain.