has been placed with Leptomyxa and Gephyramoeba in the
Family Leptomyxaidae however reservations have been raised (Page,
1983). Recent SSUrDNA data (Amaral
Zettler et al, 2000) suggest a
kinship between Rhizamoeba and Paraflabellula, in fact the
single Rhizamoeba analysed split Paraflabellula hoguae and
P. reniformis. This study also indicated a relationship to Leptomyxa
reticulata, but not to Gephyramoeba. A more recent
study supports these relationships (Peglar et
al, 2003). Rhizamoeba
together with Paraflabellula, Leptomyxa, Saccamoeba,
Hartmannella and Echinamoeba have been grouped together in
the LH lineage (Peglar et al, 2003)
by SSUrDNA gene sequence analysis although these genera are very
different in appearance!
in rapid locomotion is limax with a hyaline crescent, the rear is often
a mass of adherent colosomes. Can transform into a flabellate form
no cytoplasmic crystals. Similarity has been observed at the
ultrastructural level between Rhizamoeba and Leptomyxa (Cann,
1984). Both mononuclear and polynuclear
species described. Species described from both salt and freshwater
L.A., Nerad, T.A., O'Kelly, C.J., Peglar, M.T., Gillevet, P.M.,
Silberman, J.D. & Sogin, M.L. (2000). "A molecular reassessment
of the Leptomyxid amoebae." Protist 151, 275-282.
Cann, J.P. (1984). "The ultrastructure of Rhizamoeba
flabellata (Goodey) comb. nov., and Leptomyxa reticulata
Goodey (Acarpomyxea: Leptomyxida)." Arch.Protistenk. 128: 13-23.
(1983). "Marine Gymnamoebae." Inst.Terr.Ecol. NERC Cambridge,
Peglar, M. T., Amaral Zettler, L. A.,
Anderson, O. R., Nerad, T. A., Gillevet, P. M., Mullen, T. E., Frasca Jr,
S., Silverman, J. D., O'Kelly, C. J. & Sogin, M. L. (2003) Two new
small-subunit ribosomal RNA gene lineages within the subclass
Gymnamoebia., J.Eukaryot.Microbiol. 50, 224-232.