Leptomyxa reticulata Goodey, 1915

 

Diagnosis: Body composed of a thin transparent protoplasm; superficially resembles an endosporous mycetozoan, but no reversible cytoplasmic movement; mutinucleate with eight to twenty to several hundred nuclei; nuclei, 5-6 um in diameter, with a large endosome; nuclear division simultaneous, but not synchronous plasmotomy; plasmogamy; cysts multinucleate, by local condensation of protoplasm.

 

Dimensions: when fully extended, 3 mm. or more in length.

 

Ecology: Widely distributed in soil. Giant amoeboid organisms may be isolated from soil and other materials by the use of suitable edible bacteria supplied on a base of non-nutrient agar.

 

Remarks: Leptomyxa reticulata has been found widely distributed in the soils of Great Britain. The common occurrence of this organism in soils which have been unmanured or treated with artificial fertilizers for 100 years or more proves that it is a soil inhabitant.
Degrees of pH between 4·1 and 8·7 had no effect on the abundance of growth when a suitable bacterial strain was supplied as food on non-nutrient agar. Ninety-two very varied strains of bacteria tested as food for L. reticulata varied greatly in edibility. Bacteria producing red, violet and blue pigments were mostly inedible. There was no correlation between Gram-staining and edibility. Certain bacterial strains induced the formation of cysts by L. reticulata. This property was not correlated with their edibility.