"Bioconvection Patterns" in Cultures of Free-Swimming Organisms.
The moving polygonal patterns in dense cultures of Tetrahymena and other ciliates and flagellates look like "Benard cells," but are not due to thermal convection. They seem to be due to a similar dynamic instability that occurs when the energy input is internal and mechanical. The high concentration in the patterns may be useful in fertilization.
Platt
J R
JR