While dinoflagellates are generally known for their golden-brown color due to the pigment fucoxanthin, Cryptomonads are a specific group of algae that belong to the Cryptophyceae class. They possess the characteristic red pigments phycoerythrin and phycocyanin along with chlorophyll a and c.
It's important to note that:
* Cryptomonads are not technically dinoflagellates. They are a separate group of algae.
* Some dinoflagellates can appear red due to other pigments like astaxanthin. However, this is not their primary photosynthetic pigment.
Therefore, the answer to your question is Cryptomonads which have red photosynthetic pigments.
