Biology and ultrastructure of the mycophagus, soil testate amoeba, Phryganella acropodia (Rhizopoda, Protozoa)  <B>Biology and ultrastructure of the mycophagus, soil testate amoeba, Phryganella acropodia (Rhizopoda, Protozoa)</B><P></B><B>C. G. Ogden and P. Pitta </B><I><P> Department of Zoology, British Museum (Natural History), Cromwell Road, London SW7 5BD, UK.</I><B><P> Summary. </B>Clones of <I>Phryganella acropodia </I>were cultivated under different trophic conditions with bacteria as the food source. The doubling time was estimated to be 3 days. The edibility of four species of fungi, <I>Aspergillus</I> <I>niger, Cunninghamella echinulata, Penicillium echinulatum and Stilbella bulbicola, </I>was tested, but only <I>Penicillium enchinulatum and Stilbella bulbicola </I>were eaten and digested by the amoeba. An ultrastructure examination showed that there are two contractile vacuoles, many dictyosomes, a single nucleus with several nucleoli, and peroxisomes. The pseudopodia are filiform when attached to the substrate but change to lobose when the animal is floating. A thin organic membrane covers the aperture of resting forms.<B><P> Key words: </B><I>Phryganella acropodia - </I>Testate amoeba - Growth rate - Rhizopoda - Feeding - Fungal species - Ultrastructure -<P> Biol Fertil Soils (1990) 9:101 - 109<P>