''Anisonema'' is a genus of colorless

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 the ...

s that occur in marine, brackish, and freshwater habitats. The cell is typically ovoid, somewhat flattened, and rigid. The name ''Anisonema'' derives from

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

for "unequal thread", in reference to the two

flagella A flagellum (; ) is a hairlike appendage that protrudes from certain plant and animal sperm cells, and from a wide range of microorganisms to provide motility. Many protists with flagella are termed as flagellates. A microorganism may have f ...

that are of unequal lengths. The shorter flagellum extends forwards and propels movement with a sweeping motion, while the longer flagellum, up to three times the length of the cell, trails behind, with jerking contractions. The genus was first named by French biologist

Félix Dujardin Félix Dujardin (5 April 1801 – 8 April 1860) was a French biologist born in Tours. He is remembered for his research on protozoans and other invertebrates. Biography In 1840 he was appointed professor of geology and mineralogy at the Unive ...

his 1841 ''Histoire naturelle des zoophytes. Infusoires, comprenant la physiologie et la classification de ces animaux, et la manière de les étudier à l'aide du microscope''. , there are around 20 accepted species in the genus.

References

Euglenozoa Euglenozoa genera {{Excavata-stub