Difference between revisions of "SHELL"

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Most foraminifers construct tests (shells) covering the cell body. Composition of tests varies from organic, through agglutinated (cemented foreign grains) calcareous secreted from calcium carbonate. Foraminiferal morphologies are extremely diverse, from [[unilocular|single-chambered]], through simple multi-chambered, to more sophisticated complex forms.  
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Most foraminifers construct tests (shells) covering the cell body. Composition of tests varies from organic, through agglutinated (cemented foreign grains) to calcareous secreted from calcium carbonate.  
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The size of the test is associated with amount of the cytoplasm. "Feeding adds to the bulk of the cytoplasm" (Armstrong & Brasier 2005), therefore, the test has to enlarge. Foraminifera have developed several strategies for test enlargement during ontogeny (after Armstrong & Brasier 2005):
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- contained growth (see [[unilocular tests]] forms)
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- continuous growth (see [[unilocular tests|unilocular]] or [[bilocular tests]])
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- simple septate growth (see [[simple multilocular tests]])
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- complex septate growth (see [[complex multilocular tests]])
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These growth patterns result in a very diverse variety of [[shell architecture|test morphologies]].
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"The test is thought to reduce biological, physical and chemical stress" (Armstrong & Brasier 2005). See [[Function of the test]].
 
   
 
   
 
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Latest revision as of 20:26, 18 June 2006