A tubular process through the valve of some centric diatoms. The fultoportula consists of a central tubular process surrounded by two or more satellite pores. Externally, the fultoportula appears as either a tube or a simple pore in the valve wall. The plural form is fultoportulae.

Usually associated with the secretion of β-chitin to maintain buoyancy in the plankton.

Alternative Terms

strutted process
Fultoportulae Ex
Image Credit: Sarah Spaulding
Image (also SEM) of the external view of Stephanodiscus yellowstonensis. The external expression of marginal fultoportulae is indicated by arrows; the marginal fultoportulae are positioned below spines.
Fultoportulae Int
Image Credit: Marina Potapova
Internal view of valve of Stephanodiscus sp. showing the rimoportula (R), central fultoportula (CF) and four marginal fultoportulae (MF). Each fultoportula has two satellite pores.