Paramecium caudatum

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Paramecium caudatum
Scientific classification Edit this classification
Domain: Eukaryota
Clade: Diaphoretickes
Clade: SAR
Clade: Alveolata
Phylum: Ciliophora
Class: Oligohymenophorea
Order:
Peniculida
Family: Parameciidae
Genus: Paramecium
Species:
P. caudatum
Binomial name
Paramecium caudatum
Ehrenberg, 1833

Paramecium caudatum

cilia.[3] The cilia are used in locomotion and feeding.[2] The species is very common, and widespread in marine, brackish and freshwater environments.[4][5]

Appearance and physical characteristics

Drawing by Alfred Kahl
"Slipper animalcule", illustrated by Louis Joblot, 1718

Paramecium caudatum is 170–330 micrometres long (usually 200–300 micrometres).

pellicle is uniformly covered with cilia, and has a long oral groove, leading to deeply embedded oral cavity, lined with cilia (short, hair-like protoplasmic processes that serve as organs of locomotion and food capture). P. caudatum has two contractile vacuoles, which serve to excrete excess water taken up from the outside, regulating the water contents of the body. Radially distributed "collecting canals" give the contractile vacuoles a distinctive star-like shape.[8][7] The cell is enclosed by a cellular envelope (cortex) densely studded with spindle-shaped extrusomes called trichocysts.[4][5]

Feeding and movement

P. caudatum feed on

plasma membrane.[3] When moving through the water, they follow a spiral path while rotating on the long axis.[2]

Reproduction and life cycle

Paramecium caudatum has two nuclei (a large macronucleus and a single compact micronucleus).[9] As in other ciliates, individuals cannot survive without the macronucleus and cannot reproduce without the micronucleus.[3] Paramecia reproduce asexually, by binary fission. During reproduction, the macronucleus splits by a type of amitosis, and the micronuclei undergo mitosis. The cell then divides transversally, and each new cell obtains a copy of the micronucleus and the macronucleus.[10]

Fission may occur as part of the normal vegetative

diploid micronuclei. The old macronuclei are destroyed, and new ones are developed from the new micronuclei.[12]

Without the rejuvenating effects of autogamy or conjugation a Paramecium ages and dies.[3] Only opposite mating types, or genetically compatible organisms, can unite in conjugation.[3]

References

  1. ^ "Paramecium caudatum". Integrated Taxonomic Information System.
  2. ^ a b c d 101 Science.com: Paramecium Caudatum
  3. ^ a b c d e Paramacium
  4. ^ a b Carey, Philip G. Marine interstitial ciliates: an illustrated key. 1992. p. 128
  5. ^ a b "Paramecium caudatum". Encyclopedia of Life. Retrieved 2013-02-14.
  6. ^ FOISSNER Wilhelm; BERGER Helmut & KOHMANN Fritz (1994). Taxonomische und ökologische Revision der Ciliaten des Saprobiensystems. Band III: Hymenostomata, Prostomatida, Nassulida. Informationsberichte des Bayerischen Landesamtes für Wasserwirtschaft. p. 112.
  7. ^
    ISBN 978-1-4757-0372-6
    .
  8. S2CID 86476008
    .
  9. ^ "Paramecium". Microbus. Retrieved 17 April 2018.
  10. ^ Lynn, Denis. The ciliated protozoa: characterization, classification, and guide to the literature. Springer, 2010. 279.
  11. ^ Berger, James D. "Autogamy in Paramecium cell cycle stage-specific commitment to meiosis." Experimental cell research 166.2 (1986): 475–485.
  12. ^ Prescott, D. M., et al. "DNA of ciliated protozoa." Chromosome 34.4 (1971): 355–366.
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