The role of the organic matrix in the construction of the agglutinate shell of Centropyxis discoides (Rhizopoda: Protozoa)

Abstract

The organic matrix of the non-agglutinate shell of Centropyxis discoides is shown to be composed of a single layer of alveoli. A double layer is found only around the apertural margin from which arise four hollow pillars which support the aboral shell surface. The smooth surface around the apertural region is considered to be formed by the compression and fusion of smaller alveoli. In agglutinate specimens the alveoli are arranged around and between the grains binding them together. Both elemental iron and manganese are concentrated in the alveoli where they probably strengthen the matrix.

Keywords :

• Testate amoeba
• Centropyxis discoides
• shell structure
• organic matrix
• agglutination