Genus Parvamoeba Rogerson, 1993

 

Diagnosis: Oval in outline and never longer than 6.0 µm in length. Raised cell mass with random wrinkles and folds. Locomotion slow via extension of lobed hyaline pseudopodium, occasionally with fine radiating subpseudopodia. Floating form with finger-like pseudopodia. No cytoplasmic crystals.
At the ultrastructural level, surface with an amorphous glycocalyx some 30 nm across. Single nucleus with central nucleolus and Thecamoeba- like electron-dense layer adjacent to nuclear membrane.
Monospecific. 

 

Type species: Parvamoeba rugata Rogerson, 1993

 

Ecology: Marine.

 

Remarks: This genus was erected for the smallest described amoeba, P. rugata. This tiny amoeba has an apparently rigid, wrinkled cell surface and amorphous glycocalyx. It is so small that its LM morphology is hard to investigate, making its position in Thecamoebidae somewhat arbitrary. The finding of P. monoura – an organism with very unusual morphology, but sequence closely resembling that of P. rugata, makes the genus Parvamoeba even more mysterious (Smirnov et al. 2011).