Nucleariid

The nucleariids are a small group of amoebae with filose pseudopods, known mostly from soils and freshwater. They are distinguished from the similar vampyrellids mainly by having mitochondria with discoid cristae. Genetic studies place them near the animals and fungi; some studies place them as a sister group to the fungi.

Nucleariids are usually small, up to about 50 &mu;m in size. Nuclearia and Vampyrellidium, which are respectively parasitic on and in algae, take the form of naked amorphous cells. The other genera, Rabdiophrys, Pinaciophora, and Pompholyxophrys, are freshwater forms with hollow siliceous scales or spines. These were formerly included among the heliozoa as the Rotosphaerida.

Cristidiscoidea