Round ex Theriot, Håkansson, Kociolek, Round & Stoermer 1987 Category: Centric
TYPE SPECIES: Cyclostephanos novaezeelandiae (Cleve in Cleve & Moller) Round ex Theriot et al.
The striae of Cyclostephanos are organized into bundles, or fascicules, that extend from the valve face onto the mantle. The costae, or thickened ribs, also extend from the valve face to mantle. The costae branch on the valve mantle below the plane of the marginal spines. Marginal rimoportulae are positioned near the spines. The branching costae distinguish this genus from Cyclotella and Stephanodiscus. Note that many of these features can seen only with SEM, particularly in the smaller species.
Although species within the genus are found in a variety of habitats, some are indicators of eutrophy. In North America, smaller species of Cyclostephanos often dominate the plankton flora during spring and summer in eutrophic lakes and rivers. Many of the species are tolerant of elevated levels of total dissolved solids and are present in highly calcareous or saline waters. Cyclostephanos is probably more common that currently reported in surveys because of difficulties in identifying this genus. The genus includes C. dubius, C. damasii, C. invisitatus, C. costatilimbus, and C. tholiformis.
Cite This Page:
Spaulding, S., and Edlund, M. (2009). Cyclostephanos. In Diatoms of the United States. Retrieved May 19, 2013, from http://westerndiatoms.colorado.edu/taxa/genus/Cyclostephanos
Reviewer: Sam Rushforth