Protozoa~ Some common freshwater types with links to Micscape resources

Protozoa are a very diverse group of organisms that vary widely in size, shape, features and habit. This page gives an overview of some commonly found freshwater protozoa. The protozoa have been grouped by their major features. Some of these are artificial groups (i.e. not necessarily related to their taxonomy) but are convenient ones for the pond dipper. More about the classification of algae and protozoa.

Group		Key features	Micscape links
Flagellates (those that photosynthesise are often classed as algae)		one or more flagella (whip-like cilia), phytoflagellates are green/ photosynthesise, zooflagellates are not green <0.4 mm	Flagellated protozoa - includes Euglena, Volvox Some other common types: Monads e.g. Bodo, Choanoflagellates (flask-shaped with flared collar)
Amoeba		move with pseudopods 0.02 - 5 mm	Amoeba - Protozoa portraits Amoeba - Video gallery Amoeba - Smallest page on the web Amoeba proteus - imaged by different illumination methods
Shelled amoeba		amoeba with a shell e.g. of sand grains 0.1 - 0.4 mm	Protozoan houses - testate amoeba, Arcella, Nebela Some other common types: Chaos, Pelomyxa
Heliozoans 'Sun animalcules'		immobile, spherical with radiating hair-like pseudopods  0.01 - 1 mm	Smallest page on the web - Heliozoans, Actinosphaerium  Some other common types: Actinophrys, Acanthocystis
Ciliates - Peritrichs		cylindrical or bell-shaped bodies, undulating membrane of cilia, some stalked, often colonial and attached to animals or plants bell: <0.25mm	Bell animalcules in 3D - Campanella Ophrydium - colonial, unstalked Vorticella - observations on its motile stage Some other common types: Vorticella, Carchesium
Ciliates - Suctoria		on water plants and other animals, adult ciliates have lost cilia, sticky tentacles capture prey <0.7 mm	Acineta - Suctoria, ciliates in disguise Podophyra - an interesting ciliate Some other common types: Tokophyra, Dendrocometes (lives on gill plates of f/water shrimp)
Other ciliates	Coleps Lacrymaria Paramecium Stentor Spirostomum	various, mostly free living forms cell usually of a fixed shape but can be contractile, or extending neck, cilia of various forms, fixed mouth 0.01 - 4 mm	Smallest page on the web - ciliates, Euplotes, Stylonichia, etc. Actinobolina vorax Amphileptus Coleps - a voracious protozoa Coleps & Urotricha - predation on rotiferColpidium - Protozoa portraits Colpoda - emerging from resting stage Didinium - a master feeder Dileptus - a carnivorous protozoa eating Litonotus Dileptus - notes on it eating Cyclidium Lacrymaria olor - the 'giraffe' of the protozoan world Lacrymaria olor - microscopic 'Loch Ness monster' Litonotus - being eaten by Dileptus Paramecium - an introduction Paramecium - Protozoa portraits Paramecium - by phase contrast How to study a 'pair of mecia' parts I-III- extensive articles on microscopy techniques to study paramecium's features. Ideal for students. Stentor - introduction Stentor - in 3D Spirostomum- one of the largest ciliates Spirostomum - observations on its feeding habits Tillina Features of ciliates: Video gallery - beating cilia Cilia - an overview

Algae	First Page	Arthropods
Worms	Collecting tips	Insect stages

Other Micscape resources on protozoa:

Beginners tips on collecting and studying protozoa

A note on demonstrating food vacuoles in ciliates

Vital staining for protozoa and other related mounting techniques (vital staining = while alive)

Natural asphyxia - relaxing protozoa before mounting

Inverted microscopes - homemade viewing troughs for plankton

How fast is an amoeba- a summary of chat prompted by an email

A protozoan undergoes binary fission - with some unusual help!

Some introductory books on freshwater protozoa:

From the Pictured Key Nature series: 'How to know the Protozoa' by Jahn, Bovee and Jahn
Pub. by Wm. C. Brown Company Publishers, Dubuque, Iowa

'A beginner's guide to the collection, isolation, cultivation and identification of freshwater protozoa' by B J Finlay, A Rogerson and A J Cowling. Pub. by Culture Collection of Algae and Protozoa, Freshwater Biological Association, Cumbria, UK, 1988.

'Free living freshwater protozoa: a colour guide' by D.J. Patterson, Pub. by John Wiley & Sons, New York, Toronto. also pub. by Manson Publishing, London. UK. also pub. by U.N.S.W Press, Sydney, Australia

---

Acknowledgements: This page with links hopefully gives a useful overview, but it's neither a formal identification guide nor comprehensive. Refs. to help identify protozoa are given below.

The artificial groups and key features have been adapted from those in 'Collins field guide to freshwater life' by R Fitter and R Manuel, 1986. Any mistakes are by the web page authors!

Many thanks to all the Micscape contributors whose articles this guide links to. For clarity their names are omitted in the links above. Articles and/or images on any of the groups without links (e.g. protozoa in black type) would be welcomed.

---

to first page

An Introduction to Microscopy

Comments to the compilers Wim van Egmond and Dave Walker are welcomed.

Microscopy UK Front Page
Micscape Magazine
Article Library

All images © Wim van Egmond