Members of Rhizamoeba are characterized by their morphology when they move, which is usually monopodial (with a single ramification), alternating between a slug-like shape and a fan shape. They have either one nucleus or multiple (less than 50) nuclei.[1]
Classification
The paraphyly of the genus caused the transfer of two previously rhizamoeban species into Leptomyxa: R. australiensis and R. neglecta. As a result, only 3 species are currently confirmed as Rhizamoeba:[1]
Other possible species are not yet confirmed due to lack of published data or poor documentation.[1] Some of these are: R. schnepfiiKühn 1996/97 (considered nomen dubium since it has not been deposited to any culture collection), Trichamoeba caeruleaSchaeffer 1926 and Trichamoeba clavaSchaeffer 1926 (both transferred to Rhizamoeba in 1980[4] but poorly documented), Amoeba clavarioidesPenard 1902 (identified as R. clavarioides through light microscopy[5]), Polychaos timidumBovee 1972 (identified as R. timidum through light microscopy[6]), etc.
^Tekle YI, Grant J, Anderson OR, et al. (April 2008). "Phylogenetic placement of diverse amoebae inferred from multigene analyses and assessment of clade stability within 'Amoebozoa' upon removal of varying rate classes of SSU-rDNA". Mol. Phylogenet. Evol. 47 (1): 339–52. doi:10.1016/j.ympev.2007.11.015. PMID18180171.
^Smirnov AV, Nassonova ES, Cavalier-Smith T (February 2008). "Correct identification of species makes the amoebozoan rRNA tree congruent with morphology for the order Leptomyxida Page 1987; with description of Acramoeba dendroida n. g., n. sp., originally misidentified as 'Gephyramoeba sp.'". Eur. J. Protistol. 44 (1): 35–44. doi:10.1016/j.ejop.2007.08.001. PMID17905574.