Diatom identification, databases and resources




The CAS Diatom Collection Web Site is an ongoing project to present taxonomic information, images, records of collections, and references pertaining to diatoms and is especially valuable for keeping up with current taxonomy. Highly recommended.


The ANSP Algae Image Database


contains light micrograph images of diatom taxa from rivers throughout the USA. Many taxa are represented. There are multiple images of several to help represent within-taxon variability. 

Klaus Dieter Kemp's Diatom Database


A terrific and very extensive resource from an excellent author

The Database contains:-

  • Over 15,000 species images & over 2,350 species descriptions
  • 300 typical genus forms

The database has been developed around the collection of Friedrich Hustedt, and focuses on three elements: material, specimens and publications.


Images and information related to inland diatoms from the Antarctic continent and Subantarctic Island.

Inventory of diatoms of the Laurentian Great Lakes of North America.

The Academy's Diatom Herbarium, one of the two largest in the world, is a primary source of taxonomic and ecological information. It includes approximately 220,000 slides (curated and non-curated), of which about 5,000 are types. Materials include both fossil and recent diatoms collected from fresh, brackish, and marine habitats.  The herbarium has a long history, with many specimens dating from the 19th Century or even earlier.


In addition to its world coverage and its inclusion of fossil diatoms, the herbarium has an extensive record of materials collected as part of freshwater environmental surveys from throughout the United States. These surveys were the work of the former Department of Limnology, and its successor, the Phycology Section Patrick Center for Environmental Research. Often extending over decades, these surveys offer a unique resource for the study of long-term changes in diatom populations and ecology.