''Dileptus'' is a genus of
unicellular
A unicellular organism, also known as a single-celled organism, is an organism that consists of a single cell, unlike a multicellular organism that consists of multiple cells. Organisms fall into two general categories: prokaryotic organisms and ...
ciliate
The ciliates are a group of alveolates characterized by the presence of hair-like organelles called cilia, which are identical in structure to flagellum, eukaryotic flagella, but are in general shorter and present in much larger numbers, with a ...
s in the class
Litostomatea. Species of ''Dileptus'' occur in fresh and salt water, as well as mosses and soils. Most are aggressive predators equipped with long, mobile
proboscides lined with toxic
extrusomes, with which they stun smaller organisms before consuming them. Thirteen species and subspecies of ''Dileptus'' are recognized.
[Vďačný, Peter, and Wilhelm Foissner. Monograph of the dileptids (Protista, Ciliophora, Rhynchostomatia). Land Oberösterreich, Biologiezentrum/Oberösterreichische Landesmuseen, 2012]
''Dileptus'' species have served as
model organism
A model organism is a non-human species that is extensively studied to understand particular biological phenomena, with the expectation that discoveries made in the model organism will provide insight into the workings of other organisms. Mo ...
s used in the study of ciliary patterns,
ontogenesis
Ontogeny (also ontogenesis) is the origination and development of an organism (both physical and psychological, e.g., moral development), usually from the time of fertilization of the egg to adult. The term can also be used to refer to the stu ...
,
conjugation
Conjugation or conjugate may refer to:
Linguistics
*Grammatical conjugation, the modification of a verb from its basic form
*Emotive conjugation or Russell's conjugation, the use of loaded language
Mathematics
*Complex conjugation, the change o ...
and food acquisition.
Appearance and characteristics
''Dileptus'' bodies are typically narrow or cylindrical, and have a
macronucleus
A macronucleus (formerly also meganucleus) is the larger type of nucleus in ciliates. Macronuclei are polyploid and undergo direct division without mitosis. It controls the non-reproductive cell functions, such as metabolism
Metabolism (, ...
made up of more than a hundred scattered nodules. During
cell division
Cell division is the process by which a parent cell (biology), cell divides into two daughter cells. Cell division usually occurs as part of a larger cell cycle in which the cell grows and replicates its chromosome(s) before dividing. In eukar ...
, these nodules divide individually. At the front end of the cell is a mobile proboscis. The
cytostome
A cytostome (from ''cyto-'', cell and ''stome-'', mouth) or cell mouth is a part of a cell specialized for phagocytosis, usually in the form of a microtubule-supported funnel or groove. Food is directed into the cytostome, and sealed into vacu ...
is at the base of this organ and is well fortified with stiff
microtubular
Microtubules are polymers of tubulin that form part of the cytoskeleton and provide structure and shape to eukaryotic cells. Microtubules can be as long as 50 micrometres, as wide as 23 to 27 nanometer, nm and have an inner diameter bet ...
rods (nematodesmata). The surface of the cell is uniformly covered with cilia arranged in longitudinal rows. The body may taper at the back end, forming something like a tail. Multiple
contractile vacuole
A contractile vacuole (CV) is a sub-cellular structure (organelle) involved in osmoregulation. It is found predominantly in protists, including unicellular algae. It was previously known as pulsatile or pulsating vacuole.
Overview
The contrac ...
s lie in a row along the dorsal surface. Most ''Dileptus'' are colourless, but two nominal species carry
symbiotic
Symbiosis (Ancient Greek : living with, companionship < : together; and ''bíōsis'': living) is any type of a close and long-term biolo ...
green algae
The green algae (: green alga) are a group of chlorophyll-containing autotrophic eukaryotes consisting of the phylum Prasinodermophyta and its unnamed sister group that contains the Chlorophyta and Charophyta/ Streptophyta. The land plants ...
in their
cytoplasm
The cytoplasm describes all the material within a eukaryotic or prokaryotic cell, enclosed by the cell membrane, including the organelles and excluding the nucleus in eukaryotic cells. The material inside the nucleus of a eukaryotic cell a ...
.
[
]
History and Classification
A species of ''Dileptus'' was described by C. G. Ehrenberg in 1833, under the name ''Amphileptus margaritifer''. Eight years later, 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 Dujardin was appointed professor of geology and mineralogy at t ...
created the genus ''Dileptus'' and moved Ehrenberg's ''A. margaritifer'' to it, along with ''Dileptus anser'' Müller 1773 (now classified in '' Pseudomonilicaryon'') and ''Dileptus folium'' (now '' Litonotus cygnus''). Over the next century, many new species were described. By 1963, when Jean Dragesco published the first detailed account of the genus, it included about 50 species.[ Many traditionally recognized members of ''Dileptus'', including the well-known species '' Dileptus anser'', have been moved to other genera, such as '' Pseudomonilicaryon'' and '' Rimaleptus''.
]
Species of Dileptus
* '' Dileptus anatinus'' Golińska, 1971
* '' Dileptus beersi'' Jones, 1956
* '' Dileptus costaricanus'' Foissner, 1995
* '' Dileptus dubius'' Vuxanovici, 1959
* '' Dileptus estuarinus'' Dragesco, 1960
* '' Dileptus jonesi'' Dragesco, 1963
* '' Dileptus margaritifer'' (Ehrenberg, 1833)
* '' Dileptus multinucleatus'' Vuxanovici, 1959
* '' Dileptus sphagnicola'' Vdacny & Foissner, 2011
* '' Dileptus viridis'' (Ehrenberg, 1833) Foissner, 1987
Video Gallery
References
{{Authority control
Litostomatea
Ciliate genera
Articles containing video clips