Question

Is dinoflagellate a saprotrophic or parasitic or symbiotic

Answer 1

The dinoflagellates (Greek δῖνος dinos "whirling" and Latin flagellum "whip, scourge") are a large group of flagellate eukaryotes that constitute the phylum Dinoflagellata. Most are marine plankton, but they also are common in freshwater habitats. Their populations are distributed depending on sea surface temperature, salinity, or depth. Many dinoflagellates are known to be photosynthetic, but a large fraction of these are in fact mixotrophic, combining photosynthesis with ingestion of prey (phagotrophy).[5] In terms of number of species, dinoflagellates are one of the largest groups of marine eukaryotes, although this group is substantially smaller than diatoms.[6] Some species are endosymbionts of marine animals and play an important part in the biology of coral reefs.

Other dinoflagellates are unpigmented predators on other protozoa, and a few forms are parasitic (for example, Oodinium and Pfiesteria).

Some dinoflagellates produce resting stages, called dinoflagellate cysts or dinocysts, as part of their lifecycles.