Glossary
Like the rest of this website, the glossary is a work in progress. If we’ve missed a term, please contact us to let us know the term and references.
Frustule
A frustule is the siliceous part of a diatom cell wall. In Latin frustule means a little piece.
A frustule consists of two halves each called a theca (plural is thecae). A theca consists of a valve and, in most taxa, its associated cingulum. The larger epitheca overlaps the smaller hypotheca similar to the overlapping of the halves of a pill box or a Petri dish.
See also epitheca, hypotheca, valve, and cingulum.
Citations
Image Credit: Eduardo Morales
Image Credit: Ian Bishop
Image Credit: Eduardo Morales
An SEM image showing the ultrastructure of the frustule of Staurosirella pinnata in girdle view.
Image Credit: Ian Bishop
An SEM image of part of a frustule of Tabelllaria flocculosa. A valve, with its marginal spines, is visible at the bottom of the image. Attached to the valve are many of the copulae, or girdle bands, that make up the girdle.