Sites and Sources


The following is a partial list of texts and online sites I’ve found helpful for identifying and researching protists.


Alfred Kahl, Wimpertiere oder Ciliata (Infusoria), 1930-35

Kahl’s classic four-volume revision of the ciliates.  The taxonomy is out of date, but this richly illustrated work remains extremely useful for identification and classification.  Under German law, it entered the public domain in 2015 (70 years after Kahl’s death).  A few years ago, I scanned my copy of the book, for my own use, and I have now made the scan available for download on Internet Archive.

Alfred Kahl, Wimpertiere oder Ciliata Vol. I General Section and Prostomata (1930)

Alfred Kahl, Wimpertiere oder Ciliata Vol. II Holotricha (1931)

Alfred Kahl, Wimpertiere oder Ciliata Vol. III Spirotricha (1932)

Alfred Kahl, Wimpertiere oder Ciliata Vol. IV Peritricha and Chonotricha (1935)

Biodiversity Heritage Library   A magnificent repository of older materials.  If it’s in the public domain, and has something to do with biology, it’s probably here.   The breadth and organization of the database is staggering.  You can search the database by organism name, and the software will return a list of documents in which the organism is mentioned.   If you wish, it will take you directly to the particular pages of the work in which that organism is discussed.    Donations to BHL are tax-deductible.

Internet Archive  If the Biodiversity Heritage Library does not have a copy of an old book or journal you’re trying to find, check the Internet Archive.

Classic Taxonomic Monographs from the Aquaparadox Project  An extensive collection of monographs on marine planktonic protists: tintinnids, diatoms, dinoflagellates and more, from l’Observatoire Océanologique de Villefranche-sur-Mer.

Protocols in Protozoology  A compendium of methods and procedures, published in 1992.   The International Society of Protistologists now offers this as a free download.  Thank them by joining the Society!

Protists in general

micro*scope   When it is working, this is the most useful and authoritative internet resource for protist identification.   Unfortunately, micro*scope and its sister site bio*pedia are now receiving minimal maintenance.  The software is old and cranky, and parked on a temporary server.  These sites no longer accept edits or new specimens and collections, but are still very useful (if you catch them on a day when they happen to be working).

Protist Information Server A database containing (as of today) 81,037 images and movies of protists.  The pictures are not always of the highest quality, and the taxonomy is inconsistent.    Specimens are occasionally misidentified.   Still, it’s a great resource for identification, and often the only online site providing pictures of certain taxa.

NIES World of Protozoa An indispensable site, built by Dr. Xu Kaiqin and hosted at the National Institute for Environmental Studies, in Japan.   The site includes a very large database of morphological genus and species descriptions, lifted from various articles and books (a numbered list of the source texts under “8. Reference” in the main menu of the site).    I don’t know whether this constitutes “fair use” of copyrighted materials, but it is certainly very convenient to have written descriptions gathered together in one place.   The taxonomy is fairly up-to-date.

Image Gallery from l’Observatoire Océanologique de Villefranche-sur-Mer  Images of planktonic protists, particularly tintinnid ciliates and dinoflagellates.


The Ciliate Resource Archive     Includes Denis Lynn’s revised classification of the ciliates.

Peritriche Ciliaten   Jörg Bernhard Scheubel’s site is dedicated to peritrich ciliates, but contains  a trove of information about ciliate systematics in general.   Navigation within the site is confusing, but worth the trouble.   Some of the most useful pages — such as Scheubel’s handy “List of Illustrations” — are buried deep in the structure of the site.

Eugène Penard, 1922.  Etudes sur les Infusoires d’eau Douce


Microworld: World of Amoeboid Organisms  Ferry Siemensma’s gorgeous site.  Beautiful, and beautifully organized.

Amoebae on the Web  Alexey Smirnov’s site.  A rich and reliable source.

The Amoebae  Sutherland Maciver’s site at U. of Edinburgh. The Fascinating World of Amoeboid Organisms.  A gorgeous gallery of images by Ecki Voelcker and Steffen Clauß.  The site is dedicated to the memory of the great Swiss amoebologist Eugène Penard.

Cash, Hopkinson & Wailes, 1905-21.  The British Freshwater Rhizopoda and Heliozoa

Joseph Leidy, 1879. Fresh-water Rhizopods of North America

Eugène Penard, 1902. Faune Rhizopodique du bassin du Léman

Research Groups and Labs

Nazeefa Fatima has compiled a handy List of Protist Research Groups and Labs.

Professional societies

Interrnational Society of Protistologists  (ISOP).  ISOP was the original publisher of the Journal of Eukaryotic Microbiology (now published by Wiley), as well as the compendious 2-volume Illustrated Guide to the Protozoa.

International Society of Evolutionary Protistologists (ISEP)
International Society for Testate Amoeba Research (ISTAR)


Acta Protozoologica
European Journal of Protistology
Journal of Eukaryotic Microbiology
Protist (formerly Archiv für Protistenkunde)
Protistology  An international journal


Scientia Books Specializing in Medicine, Science, History of Medicine, History of Science, Evolution and Genetics.  An extremely helpful and honest dealer.

The Old Professor’s Bookshop   A real treasure in Belfast, Maine.  And it has a microscope!