''Mediolabrus'' is a genus of centric
diatom
A diatom (Neo-Latin ''diatoma'') is any member of a large group comprising several Genus, genera of algae, specifically microalgae, found in the oceans, waterways and soils of the world. Living diatoms make up a significant portion of Earth's B ...
s within the family
Thalassiosiraceae. Known ''Mediolabrus'' species live
plankton
Plankton are the diverse collection of organisms that drift in Hydrosphere, water (or atmosphere, air) but are unable to actively propel themselves against ocean current, currents (or wind). The individual organisms constituting plankton are ca ...
ically in
brackish
Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estuari ...
and
fresh
Fresh may refer to:
Arts, entertainment, and media Films and television
* ''Fresh'' (1994 film), a crime film
* ''Fresh'' (2009 film), a documentary film on sustainable agriculture
* ''Fresh'' (2022 film), a thriller film
*''Fresh with the Aust ...
water.
This genus, together with the related ''
Minidiscus'', includes some of the smallest diatom species with diameters as small as 1.9 μm (in ''
M.'' ''
comicus'').
Taxonomy
Genus ''Mediolabrus'' was erected in 2020 based on
molecular phylogenetics
Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...
, by transferring three species from the genus ''
Minidiscus''.
Morphology and ultrastructure
The lenticular or spherical cells, smaller than 10 μm, live solitarily or in flocks. The valves (ends of the siliceous shell) are domed, with sloping mantle (side of the valve). The areolae (regularly repeated pores) are internally covered by individual, radially continuous cribra (perforated plates) and lack typical foramens (large openings) externally. At the edge of the valve face or close to the mantle are several fultoportulae (tube-like pores). There is only one rimoportula (lip-like pore
) and no fultoportulae in the center or sub-center of the valve. Only a single rimoportula near the valve center is a diagnostic feature of this genus and the source of its name.
See also
*
Smallest organisms The smallest organisms found on Earth can be determined according to various aspects of organism size, including volume, mass, height, length, or genome size.
Given the incomplete nature of scientific knowledge, it is possible that the smallest or ...
References
External links
''Mediolabrus'' in NCBI Taxonomy*
{{Taxonbar, from=Q134127237
Thalassiosirales
Diatom genera
Taxa described in 2020