1. Chrysophytes
⇒ Unicellar
⇒ Present in water bodies with low calcium levels.
⇒ Golden yellow colour due to accessory pigment.
⇒ Cell walls made of cellulose and silica.
⇒ Free swimming.
⇒ Two unequal flagella.
2. Dinoflagellates
⇒ Dinoflagellates are essentially golden-brown, biflagellate, unicellular motile protists.
⇒ Golden brown is the primary color, but due to changes in the ratios of other pigments, it may also take on yellow, green, brown, or even blue forms.
⇒ Theca or lorica, composed of articulated and sculpted cellulose plates, is a stiff covering that typically covers cells.
⇒ One flagellum is transverse and the other is longitudinal, making the two flagella distinct (heterokont).
⇒ Mesokaryon is the name given to the big nucleus.
⇒ Chlorophyll a and chlorophyll c are found in plastids or chromatophores.
⇒ In the sea, certain dinoflagellates like Gymnodinium and Gonyaulax proliferate in vast numbers, turning the water red and resulting in the so-called "red tide."
⇒ Dinoflagellates in the ocean exhibit bioluminescence. such as Noctiluca.
3. Euglenoids
⇒ Unicellular protists called euglenoids, like the genus Euglena, are frequently found in freshwater.
⇒ The pellicle, a protein-rich cell membrane, exists in place of the cell wall.
⇒ They bear two flagella on the anterior end of the body.
⇒ A small light sensitive eye spot is present.
⇒ They can prepare their own food because they have photosynthetic pigments like chlorophyll. They act like heterotrophs when there is no light, though, by catching other tiny aquatic creatures.
⇒ They are referred regarded as the connecting link between plants and animals since they exhibit both plant and animal-like characteristics, making it difficult to categorize them.
4. Slime moulds
⇒ Chlorophyll does not exist in them.
⇒ Only the plasma membrane encloses them. The spores, however, contain cellulose cell walls.
⇒ They often reside near decomposing vegetation.
⇒ They have a diverse spectrum of coloring.
⇒ They are saprotrophic or phagotrophic feeders.