''Stephanopogon'' is a genus of flagellated marine
protist that superficially resembles a ciliate.
Characteristics
''Stephanopogon'' closely resembles certain
ciliates and was originally classified with them (, but is now considered related to heterolobosean
flagellate
A flagellate is a cell or organism with one or more whip-like appendages called flagella. The word ''flagellate'' also describes a particular construction (or level of organization) characteristic of many prokaryotes and eukaryotes and their ...
s. The cell is somewhat flattened, with multiple smooth flagella arranged in rows running from the front to the back, and has an anterior mouth supported by rods. They feed on
bacteria,
diatom
A diatom (Neo-Latin ''diatoma''), "a cutting through, a severance", from el, διάτομος, diátomos, "cut in half, divided equally" from el, διατέμνω, diatémno, "to cut in twain". is any member of a large group comprising sev ...
s, and other smaller organisms. There are 2-16
nuclei, but they are not differentiated into
macronuclei and
micronuclei as occurs in ciliates. They have a cosmopolitan distribution.

Classification
Because
nuclear dimorphism is absent, ''Stephanopogon'' had been regarded as an evolutionary intermediate between the ciliates and other protozoa, and possibly an ancestor of the animals as well. Corliss and Lipscomb showed that it is not cytologically similar to
ciliates, lacking their complex pellicle and infraciliature. Further electron microscopical studies added details to the understanding of the cytological organization of ''Stephanopogon''.
Yubuki and Leander demonstrated that ''Stephanopogon'' is closely related to ''Percolomonas'' within the Heterolobosea. The bases of the flagella in both genera are attached to an electron dense cytoskeletal material, but it has been argued that this is not an apomorphy of the clade
It has recently been included as a heterolosean in the
class
Class or The Class may refer to:
Common uses not otherwise categorized
* Class (biology), a taxonomic rank
* Class (knowledge representation), a collection of individuals or objects
* Class (philosophy), an analytical concept used differentl ...
Percolatea, along with ''
Percolomonas
''Percolomonas'' is a genus of free-living flagellate Heteroloboseans, forming a clade with ''Stephanopogon''.
The genus includes six described species (see infobox). However, ''P. cosmopolitus'' is likely a species complex containing multiple c ...
''.
The genus contains 7 species: ''S. apogon'' Borror, 1965, ''S. colpoda'' Entz, 1884, ''S. mesnili'' Lwoff, 1923, ''S. minuta'' Lei et al., 1999, ''S. mobilensis'' Jones et Owen, 1974, ''S. paramesnili'' Lei et al., 1999 and ''S. pattersoni'' Lee et al., 2014
[Lee, W. J. 2019. Small free-living heterotrophic flagellates from marine intertidal sediments of the Sydney region, Australia. Acta Protozoologica: 58 167-189.]
References
External links
Tree of Life: Stephanopogon
{{Taxonbar, from=Q293160
Flagellates
Percolozoa
Excavata genera