Domain Eukaryota
Mastigamoebae

Mastigamoeba longfilum

The Mastigamoebae, like all the Amoebozoa, exist in a state of some classification confusion.

All are flagellates at some stage, with a single long flagellum that pulls the cell forward.


The Mastigamoebae (and the related Entamoebae) seem primitive, since many of the cellular organelles found in other eukaryotes are missing. But instead of being ancient branches off the eukaryotic tree, we now know these groups once had these organelles, but they are reduced or modified.

The Mastigamoebae extrude numerous pseudopodia, can form cysts, and like low-oxygen habitats rich in dissolved nutrients.

The Mastigamoebae include (or are related to) Pelomyxa, the giant amoeba, which can reach up to 1/8 of an inch in length and visible to the naked eye. These are cylindrical with a single pseudopod and covered in tiny non-motile flagella. They can have anywhere from 2 to 200 nuclei.

Pelomyxa are found in the mud of freshwater streams. They eat a wide variety of food, almost anything they happen across, including sand and other debris.

The Mastigamoebae include Mastigella and Mastigamoeba. They are related to the Eumycetozoa, the 'slime molds'.


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