Gmelin 1788      Category: Nitzschioid
TYPE SPECIES: Bacillaria paradoxa Gmelin




Image Credit: Pat Kociolek

CLASS: Bacillariophyceae
  ORDER: Bacillariales
    FAMILY: Bacillariaceae

  1. Raphe positioned in the central apical axis
  2. Striae relatively coarse
  3. Cells grow in colonies, linked by their keels

The raphe of Bacillaria species is located within a raised keel. In contrast to the excentrically positioned raphe and keel of Nitzschia, the raphe of Bacillaria is centrally positioned along the apical axis. The striae are distinct and relatively coarse. Living cells form colonies. The colonies are joined by silica hooks near the keel, and these silica hooks allow the cells to slide past one another in coordinated movements.

Bacillaria is found in marine, brackish, and freshwaters with high conductivity and often nutrient rich conditions.

Cite This Page:
Spaulding, S., and Edlund, M. (2008). Bacillaria. In Diatoms of the United States. Retrieved April 22, 2018, from

Contributor: Sarah Spaulding | Mark Edlund - July 2008
Reviewer: Sam Rushforth - April 2010