A specialized rejuvenescent cell produced during sexual reproduction that germinates to create the initial valve, which begins asexual diatom reproduction. This cell results form sexual fusion or autogamy (i.e. zygote), or one formed by purely vegetative processes that swells to maximum size. Its wall is different from that of the normal frustule and of specialized structure. An auxospore is referred to as a free auxospore when it has no direct connection with parent cell.
References
Anon., 1975. Proposals for a Standardization of Diatom Terminology and Diagnosis. Nova Hedwigia, Beihette Symposium, 53, pp. 323-354.
Barber, H.G. & Haworth, E.Y. 1981. A guide to the morphology of the diatom frustule. Freshwater Biological Association, Ambleside, Cumbria, UK. 112 pp.
