Colpodella
Encyclopedia
Colpodella is a genus
of alveolate
s comprising 5 species, and two further possible species: They share all the synapomorphies
of apicomplexa
ns, but are free-living, rather than parasitic
. This genus was previously known as Spiromonas. This genus was once thought to be a genus of kinetoplastid
s.
The type species is Colpodella perforans.
in diameter) flagellated protists. The life cycle of consists of two main stages: flagellated trophozoites and resting cysts
.
Morphologically these trophozoites of these species of this genus are very similar to Perkinsus. The motile stages of both genera have a pair of anterior orthogonal flagella, vesicular mitochondrial cristae, inner alveolar membranes and micropores. Some species may also posses a third flagellum. Both Colpodella and Perkinsus species have open sided truncated conoids (known as the rostrum in Colpodella), rhoptries
that occupy the length of the cell and smaller microneme
s. Both the rhoptries and micronemes arise at the anterior portion of the cell. A three-membraned pellicle lies beneath the plasma membrane and is composed of the endoplasmic reticulum
and widely separated microtubule
s that arise subapically. It is present only in the anterior part of the cell. Some species have extrusive organelles (trichocyst
s).
Unlike Perkinsus, the Colpodella are free living and are voracious predators of other free living protists. With the rostrum, they penetrate through the cell membrane and consume the prey's cytoplasm. The rostrum is identical in structure and function to the conoid
of Perkinsus zoospore
s. While feeding the protist attaches its anterior portion to the prey. The rostrum then transforms into a ring of microtubules encircling the attachment zone. The cytoplasm of the prey is aspirated and drawn into a large posterior food vacuole. This mode of feeding is known as myzocytosis.
Following feeding species of both genera lose their flagella, become spherical, exhibit a large central vacuole
, encyst and divide. The cysts are simple spheres and aside from some sparsely distributed pores, are generally completely devoid of any surface features. One difference in their life cycles is that species of Colpodella produce 4 progeny per cyst
while Perkinsus species can produce up to 32 per cyst. Reproduction in this genus is by simple binary fission.
) have a closed conoid.
Another genus in this family is Acrocoelus.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of alveolate
Alveolate
The alveolates are a major line of protists.-Phyla:There are four phyla, which are very divergent in form, but are now known to be close relatives based on various ultrastructural and genetic similarities:...
s comprising 5 species, and two further possible species: They share all the synapomorphies
Synapomorphy
In cladistics, a synapomorphy or synapomorphic character is a trait that is shared by two or more taxa and their most recent common ancestor, whose ancestor in turn does not possess the trait. A synapomorphy is thus an apomorphy visible in multiple taxa, where the trait in question originates in...
of apicomplexa
Apicomplexa
The Apicomplexa are a large group of protists, most of which possess a unique organelle called apicoplast and an apical complex structure involved in penetrating a host's cell. They are unicellular, spore-forming, and exclusively parasites of animals. Motile structures such as flagella or...
ns, but are free-living, rather than parasitic
Parasitism
Parasitism is a type of symbiotic relationship between organisms of different species where one organism, the parasite, benefits at the expense of the other, the host. Traditionally parasite referred to organisms with lifestages that needed more than one host . These are now called macroparasites...
. This genus was previously known as Spiromonas. This genus was once thought to be a genus of kinetoplastid
Kinetoplastid
The kinetoplastids are a group of single-cell flagellate protozoa, including a number of parasites responsible for serious diseases in humans and other animals, as well as various forms found in soil and aquatic environments...
s.
The type species is Colpodella perforans.
Description
These are small (< 20 μmMicrometre
A micrometer , is by definition 1×10-6 of a meter .In plain English, it means one-millionth of a meter . Its unit symbol in the International System of Units is μm...
in diameter) flagellated protists. The life cycle of consists of two main stages: flagellated trophozoites and resting cysts
Microbial cyst
A microbial cyst is a resting or dormant stage of a microorganism, usually a bacterium or a protist, that helps the organism to survive in unfavorable environmental conditions. It can be thought of as a state of suspended animation in which the metabolic processes of the cell are slowed down and...
.
Morphologically these trophozoites of these species of this genus are very similar to Perkinsus. The motile stages of both genera have a pair of anterior orthogonal flagella, vesicular mitochondrial cristae, inner alveolar membranes and micropores. Some species may also posses a third flagellum. Both Colpodella and Perkinsus species have open sided truncated conoids (known as the rostrum in Colpodella), rhoptries
Rhoptry
A rhoptry is a specialized secretory organelle. They are club-shaped organelles connected by thin necks to the extreme apical pole of the parasite. These organelles, like micronemes, are characteristic of the motile stages of Apicomplexa protozoans. They can vary in number and shape and contain...
that occupy the length of the cell and smaller microneme
Microneme
Micronemes are cellular organs, or organelles, possessed by Apicomplexa protozoans that are restricted to the apical third of the protozoan body. They are surrounded by a typical unit membrane. On electorn microscopy they have an electron-dense matrix due to the high protein content...
s. Both the rhoptries and micronemes arise at the anterior portion of the cell. A three-membraned pellicle lies beneath the plasma membrane and is composed of the endoplasmic reticulum
Endoplasmic reticulum
The endoplasmic reticulum is an organelle of cells in eukaryotic organisms that forms an interconnected network of tubules, vesicles, and cisternae...
and widely separated microtubule
Microtubule
Microtubules are a component of the cytoskeleton. These rope-like polymers of tubulin can grow as long as 25 micrometers and are highly dynamic. The outer diameter of microtubule is about 25 nm. Microtubules are important for maintaining cell structure, providing platforms for intracellular...
s that arise subapically. It is present only in the anterior part of the cell. Some species have extrusive organelles (trichocyst
Trichocyst
http://media-2.web.britannica.com/eb-media/68/8968-004-A94DB3DF.jpg A trichocyst is a structure in the cortex of certain ciliate and flagellate protozoans consisting of a cavity and long, thin threads that can be ejected in response to certain stimuli...
s).
Unlike Perkinsus, the Colpodella are free living and are voracious predators of other free living protists. With the rostrum, they penetrate through the cell membrane and consume the prey's cytoplasm. The rostrum is identical in structure and function to the conoid
Conoid
In geometry, a conoid is a Catalan surface all of whose rulings intersect a fixed line, called the axis of the conoid. If all its rulings are perpendicular to its axis, then the conoid is called a right conoid....
of Perkinsus zoospore
Zoospore
A zoospore is a motile asexual spore that uses a flagellum for locomotion. Also called a swarm spore, these spores are created by some algae, bacteria and fungi to propagate themselves.-Flagella:...
s. While feeding the protist attaches its anterior portion to the prey. The rostrum then transforms into a ring of microtubules encircling the attachment zone. The cytoplasm of the prey is aspirated and drawn into a large posterior food vacuole. This mode of feeding is known as myzocytosis.
Following feeding species of both genera lose their flagella, become spherical, exhibit a large central vacuole
Vacuole
A vacuole is a membrane-bound organelle which is present in all plant and fungal cells and some protist, animal and bacterial cells. Vacuoles are essentially enclosed compartments which are filled with water containing inorganic and organic molecules including enzymes in solution, though in certain...
, encyst and divide. The cysts are simple spheres and aside from some sparsely distributed pores, are generally completely devoid of any surface features. One difference in their life cycles is that species of Colpodella produce 4 progeny per cyst
Cyst
A cyst is a closed sac, having a distinct membrane and division on the nearby tissue. It may contain air, fluids, or semi-solid material. A collection of pus is called an abscess, not a cyst. Once formed, a cyst could go away on its own or may have to be removed through surgery.- Locations :* Acne...
while Perkinsus species can produce up to 32 per cyst. Reproduction in this genus is by simple binary fission.
Taxonomy
This family appears to be a sister clade to the Apicomplexa. Their life style may be representative of the free living ancestors of the Apicomplexa. One significant difference is that this genus, like the Perkinsea, have an open sided conoid while the Apicomplexa which posses a coniod (the ConoidasidaConoidasida
Conoidasida is a class of protists.The class was defined in 1988 by Levine and contains two subclasses - the coccidia and the gregarines. All members of this class have a complete, hollow, truncated conoid...
) have a closed conoid.
Another genus in this family is Acrocoelus.
- Colpodella edax (Klebs, 1892) Simpson & Patterson, 1996
- Colpodella gonderi (Foissner & Foissner, 1984) Simpson & Patterson, 1996
- Colpodella perforans (Hollande, 1938) Patterson & Zölffel, 1991
- Colpodella pontica
- Colpodella pugnax Cienkowsky, 1865
- Colpodella unguis Patterson & Simpson, 1996
- Colpodella vorax (Kent, 1880) Simpson & Patterson, 1996
- ?Colpodella angusta (Dujardin, 1841) Simpson & Patterson, 1996
- ?Colpodella turpis Simpson & Patterson, 1996