Lorica (biology)

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In biology, a lorica is a shell-like protective outer covering, often reinforced with sand grains and other particles that some protozoans and loriciferan animals secrete. [1] Usually it is tubular or conical in shape, with a loose case that is closed at one end. [2] An example is the protozoan genus Stentor , in which the lorica is trumpet-shaped. In the tintinnids, the lorica is frequently transparent and is used as a domicile. [3] Halofolliculina corallasia has a lorica that is attached as an outer structure, and into which it retracts when disturbed. [4]

Contents

Formation Process

There are three phases in the formation of lorica: agglomeration in a natural cast; helical extension; and stabilization. [5]

Agglomeration

During agglomeration, the organism collects and assembles particles from its environment. These particles are then used to construct the initial framework of the lorica.

Helical Extension

In the helical extension phase, the lorica is extended and shaped, often with a helical or spiral growth pattern. This phase involves the secretion of materials by the organism to reinforce the structure.

Stabilization

The final phase, stabilization, involves the hardening and completion of the lorica. This process ensures that the lorica is durable and capable of providing effective protection.

Ecological Role

The lorica serves several ecological roles:

Etymology

The original meaning of the word "lorica" is cuirass, a type of chest armor, originally made of leather, afterward of plates of metal or horn sewn on linen or the like. [6]

Research and Studies

Research on loricae has provided insights into the evolutionary adaptations and ecological strategies of microorganisms. Studies have focused on the structural diversity, material composition, and the genetic mechanisms underlying lorica formation. [7]

See also

Notes

  1. Davis, Charles C. (1 January 1981). "Variations of lorica shape in the genus Ptychocylis (Protozoa: Tintinnina) in relation to species identification". Journal of Plankton Research. 3 (3): 433–443. doi:10.1093/plankt/3.3.433.
  2. "lorica (biology) -- Britannica Online Encyclopedia". britannica.com. Retrieved 2009-08-16.
  3. "Mic-UK: TINTINNINAE". www.microscopy-uk.org.uk. Retrieved 2009-08-16.
  4. Taylor, Michael W.; Radax, Regina; Steger, Daria; Wagner, Michael (2007). "Sponge-Associated Microorganisms: Evolution, Ecology, and Biotechnological Potential". Microbiology and Molecular Biology Reviews. 71 (2): 295–347. doi:10.1128/MMBR.00040-06. PMC   2176056 . PMID   17554047.
  5. Laybourn-Parry, J. A. (31 January 1992). Protozoan plankton ecology Three phases of lorica formation. ISBN   9780412344404 . Retrieved 2009-08-16.
  6. "Etymology of Lorica". Online Etymology Dictionary. Retrieved July 30, 2024.
  7. Gutiérrez-Rodríguez, A. (2013). "New perspectives on the functional morphology of the lorica in tintinnid ciliates". Marine Micropaleontology. 104: 1–16. doi:10.1016/j.marmicro.2013.08.002.

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