What are three primary characteristics of organisms in the phylum Dinoflagellata?

1. Most are marine plankton, but they are common in fresh water habitats as well.

2. They make an important part of the aquatic food chain.

3. These make up the largest group of eukaryotic algae aside from the diatoms.

4. Half of all these Photosynthetic.

5. Some dinoflagellates are colour-less predators on other protozoa, and a few forms are parasitic.

6. An algal bloom of dinoflagellates can result in a visible discoloration of the water colloquially known as red tide.

All within the first paragraph of wikipedia.

Dinoflagellata