Genus Leptomyxa Goodey, 1915, emend. Smirnov et al., 2016

 

Diagnosis: Amoebae of various shape, from limax-like to branched, expanded, reticulate plasmodia like organisms. Low-mobile or non-mobile cells can adopt expanded, comet-like shape. Various numbers of nuclei – from one to several thousands.

Ultrastructure: In the SSU rDNA sequence remarkable deletion of ca. 35 nucleotides starting from the position 252  and insertion of ca. 15 nucleotides starting from the position 730 (in the sequence AF293898 Leptomyxa cf. reticulata) against sequences of Flabellula spp. and Rhizamoeba spp.

Type species: L. reticulata Goodey, 1914.

Known species:

1. Leptomyxa reticulata Goodey, 1915
2. Leptomyxa flabellata Goodey, 1915
3. Leptomyxa australiensis (Chakraborty et Pussard, 1985) Smirnov et al. 2016
4. Leptomyxa neglecta (Smirnov, Nassonova, Fahrni et Pawlowski, 2009) Smirnov et al. 2016
5. Leptomyxa arborea Berney, Geisen et Burberg 2016
6. Leptomyxa variabilis Geisen et Burberg 2016

 

Ecology: free-living and widespread in soil, fresh water.

 

Remarks: This genus closely resembles the genus Rhizamoeba. The main difference is the absence of a limax form in Leptomyxa.

 

Key to the species (under construction):

 

1

Nuclei with a single, more or less central nucleolus

L. reticulata
-

Nuclei with one to three irregularly shaped nucleoli

L. fragilis