Seta

Septum

 

Sigmoid

A simple or robust extension of the diatom valve. The plural form is setae. Setae are more elongate than spines and are found in the genera Chaetoceros and Bacteriastrum. They join frustules together to form chains and maintain the buoyancy of colonies in a planktonic environment.


Citations

Barber, H.G. and Hayworth, E.Y. (1981). Guide to the Morphology of the Diatom Frustule. Freshwater Biological Association, 112 pp.