Theses and Dissertations

Issuing Body

Mississippi State University


Brown, Matthew W.

Committee Member

Outlaw, Diana C.

Committee Member

Silberman, Jeffery D.

Date of Degree


Document Type

Graduate Thesis - Open Access


Biological Sciences (Microbiology)

Degree Name

Master of Science


College of Arts and Sciences


Department of Biological Sciences


Many groups of protists, also known as microbial eukaryotes, remain understudied. One such group, the superfamily Sainouroidea in the supergroup Rhizaria has been shown to be a molecularly diverse and divergent clade by recent environmental sequencing. Here we isolated and analyzed cultures of Sainouroid amoebae using 18S rDNA sequencing, light microscopy, and TEM. Using a molecular species concept we described four novel genera and twelve novel species in Sainouroidea. Another understudied group Cutosea, in the supergroup Amoebozoa, contains the ATCC isolate PRA-29, which is an amoeba that has been used in many phylogenomic datasets. PRA-29 was incorrectly identified as Pessonella sp. Here we studied PRA-29 in detail using light microscopy, TEM, and SEM and re-classify it as Armaparvus languidus novel genus, novel species. We show that a cell coat of microscales separated from the cell membrane is a unique trait found in all known Cutosean amoebae.