Limnogromia sinensis, China

 

 

Family Allogromiidae Rhumbler, 1904

 

Diagnosis: Test globular to tubular, with a single terminal aperture; test membraneous or pseudochitinious, in some cases with agglutinated foreign material; usually the cytoplasm forms a tubular string inside the test towards the pseudostome; cells uninucleate or multinucleate; complex life-cycles are observed in some species.

 

Remarks: The Allogromiidae belong to the Foraminifera and are widely distributed in marine and brackish habitats. Some members of this family occur in fresh water, but are rare. The main reason is probably that light microscopically these tests are hard to discover between debris, despite of their relatively large size (average 250 µm, but up to 1 mm). Usually the amoebae spread out their beautiful pseudopodial network when kept on microscope slides in moist chambers or in culture dishes.  Amoeboid organisms with granular reticulopodia are members of the phylum Granuloreticulosa. Reticulopodia are characterized by the presence of bidirectional streaming and the absence of microtubules. They form anastomosing networks which can be very large, up to several millimeters in some species.

 

Lacogromia cassipara, morphotype B; a adult specimen; b young specimens, just 24 hous after schizogony - drawing and micrograph Ferry Siemensma