Taxonomic Tools
Also see Taxonomic References pageKeys, all taxa:
Marine Species Identification Portal: information on 9900 species in the world's oceans and seas, both pelagic and benthic. Excellent keys by world authorities for euphausiid and Aetideid copepods, ostracods near Great Britain, North Sea zooplankton and South Atlantic plankton. Species pages are linked via images of the organisms. Developed by ETI BioInformatics.
Arctic Ocean Diversity: by R. Hopcroft, University of Alaska Fairbanks. Image based guide to zooplankton groups of the Arctic waters with lots of great photographs of live specimens.
Australian Marine Zooplankton: a taxonomic guide and atlas: by Kerrie Swadling and Anthony Richardson at the Institute for Marine and Antarctic Studies, University of Tasmania. Has image based keys for copepods, ostracods, cladocera, malacostraca, Noctiluca, cnidaria, ctenophores, annelids, molluscs, bryozoans, chaetognaths, appendicularia, echinoderms, phoronids. Also available are downloadable fact sheets for sopeods, jellyfish/cladocerans and general information about zooplankton, references and more.
Crustacean.net: by the Australian Museum. Includes amphipoda, anaspidacea, anomura, calanoid copepods (families, by J. Bradford-Grieve), isopoda, mictacea, mysidaea (families, subfamilies, tribes by K. Meland), remipedia, spelaeogriphacea, stomatopoda, tanaidacea. A few families have interactive keys which require Intkey to be installed on your computer (free download).
ZIMNES: by SAHFOS, Plymouth, UK. The goal of these pages is to provide a tool which can help both experienced zooplankton taxonomist and students just starting to learn identification of zooplankton. Currently, these pages are under construction but will eventually include a visual key. The taxonomic tree gives information about phyla, some images and references.
An Image-Based Key To The Zooplankton Of The Northeast (USA): by Jim Haney and students at University of New Hampshire, USA. Covers common rotifers, cladocera, copepoda, and some other arthropoda found in New Hampshire fresh and coastal waters.
Guide to the Marine Zooplankton of south eastern Australia: Both an image based key and a diagnostic tool to distinguish local groups. Eventually each links through to separate species/taxon pages. Diagnostic key requires free download of Lucid software and java-enabled web browser.
ICES Zooplankton Identifcation Leaflets: pdf format
"Guide to the Coastal and Surface Zooplankton of the South-western Indian Ocean" by Conway, D.V.P., White, R.G., Hugues-Dit-Ciles, J., Gallienne, C.P. and Robins, D.B. (2003). Occasional Publications. Marine Biological Association of the United Kingdom (15) 354p. - The species list is based on zooplankton sampling carried out round the coastal areas of the islands of Mahé and Aldabra (Seychelles), Rodrigues (Mauritius), Madagascar and from a sampling transect between Seychelles and Rodrigues. The guide therefore includes a high proportion of the island-coastal and surface water zooplankton of the whole Indian Ocean. The location where a particular species has been sampled has been noted and some species that have not been sampled, but are known to occur in the region, have been included. Comprehensive taxonomic information has not been presented, but sufficient information should be given to identify each species.
Keys, specific taxa:
Ciliates:
"The user-friendly guide to coastal planktonic ciliates" by Planktonic Ciliate Project, University of Liverpool, UK. The guide is quite nice and the experts were involved, although few species are listed.
Ostracods:
Atlas of Atlantic Planktonic Ostracods by Martin Angel, Kasia Blachowiak-Samolyk and Vladimir Chavtur with the assistance of the British Natural History Museum. An extensive and authoritative guide to includes descriptions, maps, illustrations and photographs.
Atlas of Southern Ocean Planktonic Ostracods by M. Angel and K. Blachowiak-Samolyk. It includes a description of the ostracod group, a list of all known species with the depth zone they inhabit, an interactive list of Southern Ocean species that includs maps, drawings and desriptions, a comprehensive bibliography and helpful ostracod links.
Marine Planktonic Ostracods: M.V. Angel. Ostracods from waters around Great Britain.
Copopods:
Diversity and Geographic Distribution of Marine Planktonic Copepods by Claude Razouls, Francis de Bovée and Juliana Kouwenberg at Observatoire Océanologique de Banyuls, Université Pierre et Marie Curie (Paris) - thorough, continually updated, excellent resource. Includes extensive references, figures, maps of all described species of copepods.
"A Key for the Identification of the More Common Planktonic Copepoda of Indian Coastal Waters" by L. R. Kasturirangan, 1963
Aetideidae of the World Ocean: by E. L. Markhaseva. Developed by ETI BioInformatics.
Euphausiids:
Euphausiids of the World: by Brinton, Ohman, Townsend, Knight, Bridgeman, Scripps Inst. Oceanogrpahy. Also available on dvd. Developed by ETI BioInformatics.
Chaetognaths:
Chaetognatha of the World: by Annelies Pierrot-Bults, Zoological Museum, University of Amsterdam and the World Biodiversity Database. Covers all described species with an image, description, references, etc. for each.
Other types of References:
pdf's:
A collection of
classic taxonomic texts: free downloads: copepods, 
medusae, 
ctenophores
More classic copepod texts from the Internet Archive: Brady, Breeman, Giesbrecht, Sars, etc.
Giesbrecht, W., Systematik und Faunistik der Pelagischen Copepoden des Golfes von Neapel und der Angrenzenden Meeres-Abschnitte: Atlas von 54 Tafeln nebst den Tafelerklarungen. Vol. 19 Text (34 MB) and vol. 19 Plates (28.6 MB). 1892, Berlin: Verlag Von R. Friedlander & Sohn.
Plankton of the offshore waters of the Gulf of Maine. By Henry B. Bigelow. 1926: pdf; NW Atlantic; somewhat out of date. Available on the Biodiversity Heritage Library website.
Rose, M., Copépodes pélagiques. Faune de France, ed. P. Lechevalier. Vol. 26. 1933, Paris: Fédération Française des Sociétés de Sciences Naturelles. 374 pp. (14.8 MB)
"A Key for the Identification of the More Common Planktonic Copepoda of Indian Coastal Waters" by L. R. Kasturirangan, 1963
websites:
The World of Copepods: Bibliography, taxonomic list, databases of researchers, specimens, genera. Also, links to other copepod sites.
Marine Biology Links : lists on a variety of topics from Warren Curry at Ohio University; The Plankton Net blog: Plankton Ecology, Marine Biology and Biological Oceanography - student oriented site; some links out of date.
All groups: Plankton net: The Alfred Wegener Institute for Polar and Marine Research (AWI) has a very comprehensive database with millions of pictures and identification help online.
CD's/DVD's:
The DVD version of the book "Zooplankton of the South Atlantic Ocean" has a guide to many taxa. Available from ETI Bioinformatics, Multimedia Interactive Software. Also see on-line version.
Also from From the same source find Copepods - Aetideidae of the World Ocean. Also see on-line version.
Euphausiids of the World: by Brinton, Ohman, Townsend, Knight, Bridgeman, Scripps Inst. Oceanogrpahy. Also available on dvd. Developed by ETI BioInformatics. Also see on-line version.
Ostracods around Great Britain: : M.V. Angel. Ostracods from waters around Great Britain. Developed by ETI BioInformatics. Also see on-line version.