A flagellate is a cell or organism with one or more whip-like appendages called flagella. The word flagellate also describes a particular construction characteristic of many prokaryotes and eukaryotes and their means of motion. The term presently does not imply any specific relationship or classification of the organisms that possess flagella. However, the term "flagellate" is included in other terms which are more formally characterized.
Euglenids or euglenoids are one of the best-known groups of flagellates. They are excavate eukaryotes of the phylum Euglenophyta, classified as class Euglenida or Euglenoidea. Euglenids are commonly found in freshwater, especially when it is rich in organic materials, with a few marine and endosymbiotic members. Many euglenids feed by phagocytosis, or strictly by diffusion. A monophyletic group known as Euglenophyceae have chloroplasts and produce their own food through photosynthesis. This group is known to contain the carbohydrate paramylon.
Bodo saltans is a free-living nonparasitic species of kinetoplastid flagellated phagotrophic protozoa that feed on bacteria. Bodo saltans cells have been reported in freshwater and marine environments.
Trimastix is a genus of excavate protists, the sole occupant of the order Trimastigida. Trimastix are bacterivorous, free living and anaerobic. It was first observed in 1881 by William Kent. There are few known species, and the genus's role in the ecosystem is largely unknown. However, it is known that they generally live in marine environments within the tissues of decaying organisms to maintain an anoxic environment. Much interest in this group is related to its close association with other members of Preaxostyla. These organisms do not have classical mitochondria, and as such, much of the research involving these microbes is aimed at investigating the evolution of mitochondria.
Katabia is a genus of soil-dwelling heterotrophic flagellate cercozoans containing the single species Katabia gromovi, and the only member of family Katabiidae.
Peranema is a genus of free-living phagotrophic euglenids. There are more than 20 nominal species, varying in size between 8 and 200 micrometers. Peranema cells are gliding flagellates found in freshwater lakes, ponds and ditches, and are often abundant at the bottom of stagnant pools rich in decaying organic material. Although they belong to the class Euglenoidea, and are morphologically similar to the green Euglena, Peranema have no chloroplasts, and do not conduct autotrophy. Instead, they capture live prey, such as yeast, bacteria and other flagellates, consuming them with the help of a rigid feeding apparatus called a "rod-organ." Unlike the green euglenids, they lack both an eyespot (stigma), and the paraflagellar body (photoreceptor) that is normally coupled with that organelle. However, while Peranema lack a localized photoreceptor, they do possess the light-sensitive protein rhodopsin, and respond to changes in light with a characteristic "curling behaviour."
Tracheloraphis is a genus of ciliates in the family Trachelocercidae.
Neobodo are diverse protists belonging to the eukaryotic supergroup Excavata. They are Kinetoplastids in the subclass Bodonidae. They are small, free-living, heterotrophic flagellates with two flagella of unequal length used to create a propulsive current for feeding. As members of Kinetoplastids, they have an evident kinetoplast There was much confusion and debate within the class Kinetoplastid and subclass Bodonidae regarding the classification of the organism, but finally the new genera Neobodo was proposed by Keith Vickerman. Although they are one of the most common flagellates found in freshwater, they are also able to tolerate saltwater Their ability to alternate between both marine and freshwater environments in many parts of the world give them a “cosmopolitan” character. Due to their relatively microscopic size ranging between 4–12 microns, they are further distinguished as heterotrophic nanoflagellates. This small size ratio limits them as bacterivores that swim around feeding on bacteria attached to surfaces or in aggregates.
Petalomonas is a genus of phagotrophic, flagellated euglenoids. Phagotrophic euglenoids are one of the most important forms of flagellates in benthic aquatic systems, playing an important role in microbial food webs. The traits that distinguish this particular genus are highly variable, especially at higher taxa. However, general characteristics such as a rigid cell shape and single emergent flagellum can describe the species among this genus.
Heteronema is a genus of phagotrophic, flagellated euglenoids that are most widely distributed in fresh water environments. This genus consists of two very distinguishable morphogroups that are phylogenetically closely related. These morphogroups are deciphered based on shape, locomotion and other ultrastructural traits. However, this genus does impose taxonomic problems due to the varying historical descriptions of Heteronema species and its similarity to the genus Paranema. The species H. exaratum, was the first heteronemid with a skidding motion to be sequenced, which led to the discovery that it was not closely related to H. scaphrum, contrary to what was previously assumed, but instead to a sister group of primary osmotrophs. This suggests that skidding heteronemids can also be distinguished phylogenetically, being more closely related to Anisoma, Dinema and Aphageae, than to other species within Heteronema.
Urceolus is a genus of heterotrophic flagellates belonging to the Euglenozoa, a phylum of single-celled eukaryotes or protists. Described by Russian biologist Konstantin Mereschkowsky in 1877, its type species is Urceolus alenizini. Species of this genus are characterized by deformable flask-shaped cells that exhibit at least one flagellum that is active at the tip, arising from a neck-like structure that also hosts the feeding apparatus. They are found in a variety of water body sediments across the globe. According to evolutionary studies, Urceolus belongs to a group of Euglenozoa known as peranemids, closely related to the euglenophyte algae.
Urceolus cyclostomus is a species of heterotrophic flagellates. It was initially described by Friedrich Stein in 1878 as Phialonema cyclostomum, from an unknown location. Due to its morphological similarities to Urceolus alenizini, the author of the latter, Konstantin Mereschkowsky, transferred it to the genus Urceolus in 1881. Like other species of the genus, its cells have a neck and a wide aperture to a canal that hosts a single flagellum and its feeding apparatus. It is distinguished from other species by a significantly more rigid cell shape, among other traits. It can be found in the bottom sediment of freshwater and brackish water bodies, as a consumer of algae.
Ploeotia is a genus of heterotrophic flagellates belonging to the Euglenida, a diverse group of flagellated protists in the phylum Euglenozoa. Species of Ploeotia are composed of rigid cells exhibiting two flagella. The genus was described by Félix Dujardin in 1841.
The peranemids are a group of phagotrophic flagellates, single-celled eukaryotes or protists. They belong to the Euglenida, a diverse lineage of flagellates that contains the closely related euglenophyte algae. Like these algae, peranemids have flexible cells capable of deformation or metaboly, and have one or two flagella in the anterior region of the cell. They are classified as family Peranemidae (ICZN) or Peranemataceae (ICBN) within the monotypic order Peranemida (ICZN) or Peranematales (ICBN).
Spirocuta is a clade of euglenids, single-celled eukaryotes or protists belonging to the phylum Euglenozoa. They are distinguished from other euglenids by active deformation of their cell shape, a process called euglenid motion or metaboly. This is made possible by a high number of spirally arranged protein strips that run below their cell membrane and confer the cell with flexibility. These strips compose the helicoidal pellicle, a trait referenced by the alternative name Helicales.
Anisonemia is a clade of single-celled protists belonging to the phylum Euglenozoa, relatives of the Euglenophyceae algae. They are flagellates, with two flagella for locomotion. Anisonemia includes various phagotrophic species and a group of primary osmotrophic protists known as Aphagea.
Urceolus cornutus is a species of heterotrophic flagellates present in marine environments. Described in 1990 by Jacob Larsen and David Patterson from sediment samples off the coast of Fiji, it is distinguished from other species by very fine and compact pellicle stripes that follow an S-helix shape, and a collar with a regular or symmetrical outline.
Rapaza viridis is a species of single-celled flagellate within the Euglenophyceae, a group of algae. It is the only species within the genus Rapaza, family Rapazidae and order Rapazida. It was discovered in a tide pool in British Columbia and described in 2012.
Neometanema is a genus of phagotrophic flagellates belonging to the Euglenida, a diverse group of flagellates in the phylum Euglenozoa. It is the sole genus within the monotypic family Neometanemidae and suborder Metanemina. It composes the order Natomonadida together with a closely related clade of osmotrophs known as Aphagea.
Pteridomonas is a genus of heterotrophic flagellates belonging to the phylum Ochrophyta. It was described in 1890 by Eugène Penard. Species of this genus descend from a group of photosynthetic algae but have secondarily lost their chloroplasts. They are single-celled flagellates, attached to the substrate by a stalk and distinguished by a ring of tentacles around the single flagellum. They can be found in marine, brackish or freshwater environments.
