Ross and Sims 1978      Category: Symmetrical biraphid
TYPE SPECIES: Krasskella kriegeriana (Krasske) Ross and Sims




Image Credit: Ian Bishop, Sarah Spaulding

CLASS: Bacillariophyceae
  ORDER: Naviculales
    FAMILY: Naviculaceae

  1. Valves small
  2. Proximal raphe ends distant
  3. Striae composed of an elongate areola on valve face

Valves are small and elongate. The axial and central areas are linear. Striae composed of an elongate areola on valve face and a circular areola on the valve mantle. The proximal raphe ends distant and the raphe fissures are slightly oblique. Helictoglossae at the proximal and distal raphe ends are not well developed. Frustules rectangular in girdle view.

Krasskella currently includes only three species, K. kriegeriana, K. hyalina Carter and Denny and K. manguinii Lange-Bertalot and Rumrich. The valves are small, and likely, have been overlooked in surveys. In North America, K. kriegeriana is not uncommon in cold, nutrient poor rivers of the California Sierra Nevada Range.

Cite This Page:
Bishop, I., and Spaulding, S. (2014). Krasskella. In Diatoms of the United States. Retrieved April 22, 2018, from

Contributor: Ian Bishop | Sarah Spaulding - August 2014