University College London’s Micropaleontology Unit presents an excellent description of fossil ostracodes along with scanning electron micrographs of fossilized shells from numerous species:  http://www.ucl.ac.uk/GeolSci/micropal/ostracod.html

 

    The University of Guelph includes a description of the biology of all groups of crustaceans appearing in freshwater, together with single photos of each group: http://www.aquatic.uoguelph.ca/inverts/diver/arthropoda/Crustacea.htm

    Selected photos of various microinvertebrates, including ostracodes, are available at a web site by Wim van Egmond:  http://www.microscopy-uk.org.uk/micropolitan/index.html

    A small collection of ostracode photos appears at a web site maintained by the Victoria museum (Australia), but is limited to marine species:  http://www.museum.vic.gov.au/crust/list.html#ostracod

    Cladocerans and copepods from the south-central United States (Missouri State University):  http://www.cnas.missouristate.edu/zooplankton/default.htm

    Cladocerans (primarily Daphnia species) from North America (University of Guelph): http://www.cladocera.uoguelph.ca/

    Rotifers, cladocerans, and copepods from the northeastern United States (University of New Hampshire):  http://cfb.unh.edu/CFBkey/index.html