Animal-like Protists and Their Characteristics

Animal-Like Protists

• All animal-like protists are heterotrophs, except Phytomastigophora, which are autotrophic.

Flagellated Animal-Like Protists (Protozoans)

• Possess flagella for locomotion.
• May be free-living aquatics, parasites, commensals, or symbionts.
• Phytoflagellates are aquatic and live in fresh or marine waters.
• Zooflagellates are generally uninucleated, occasionally multinucleate.

Amoebid Animal-Like Protists (Protozoans)

• Develop pseudopodia (temporary protoplasmic outgrowths) for locomotion and engulfing food articles.
• Sarcodines are mostly free-living (e.g., Amoeba proteus) and found in fresh water, sea water, and on damp soil.
• Some species, like Entamoeba histolytica, are parasitic.

Sporozoans

• All sporozoans are endoparasites.
• Some sporozoans, such as Eimeria sp., cause severe diseases like coccidiosis in birds.
• Nutrition is parasitic (absorptive), and phagotrophy is rare.

Ciliated Animal-Like Protists (Protozoans)

• Ciliates develop a number of cilia during a part or whole of the life cycle.
• Use cilia for locomotion and driving food.
• Show a high degree of morphological and physiological specialization.
• Have definite regions for ingestion and egestion.
• The region of ingestion consists of an oral groove.