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Placozoans: Placozoa

Physical Characteristics, Behavior And ReproductionGEOGRAPHIC RANGE, HABITAT, DIET, PLACOZOANS AND PEOPLE, CONSERVATION STATUS



Scientists do not know whether placozoans are widely distributed around the world. These animals are so hidden that their diversity may be much greater than scientists realize. The placozoans that have been studied are samples cultured in laboratory aquariums near warm seas.




Scientists do not know where placozoans live under natural conditions. They may live on the surface of underwater rocks and on the shells of bottom-dwelling sea animals.


Placozoans eat waste material, protozoans (proh-tuh-ZOH-uhns), and algae (AL-jee). Protozoans are one-celled living things that resemble animals in that they get their food from their surroundings rather than making it themselves as plants do. Algae are plantlike growths that live in water and have no true roots, stems, or leaves.


Placozoans have no known importance to humans.


Placozoans are not threatened or endangered.

FOR MORE INFORMATION

Books:

Grel, Karl G., and A. Ruthmann. "Placozoa." In Microscopic Anatomy of Invertebrates: Placozoa, Porifera, Cnidaria, and Ctenophora. Edited by Frederick W. Harrison and J. A. Westfall. New York: Wiley, 1991.


Web sites:

Howey, Richard L. "A Weird Wee Beastie: Trichoplax adhaerens." Microscopy-UK. http://www.microscopy-uk.org.uk/mag/indexmag.html? http://www.microscopy-uk.org.uk/mag/artoct98/tricho.html (accessed on December 13, 2004).

"Introduction to Placozoa: The Most Simple of All Known Animals." University of California, Berkeley, Museum of Paleontology. http://www.ucmp.berkeley.edu/images/WebLiftComb.gif (accessed on December 13, 2004).

Additional topics

Animal Life ResourceJellyfish, Sponges, and Other Simple Animals