"Protozoans"
           "amoebas"
                      Actinosphaerium
                      Actinophryes
                      Difflugia
                      Sphaerastrum
           "flagellates"
                      Ceratium
                      Trachylomonas
                      Volvox
           "ciliates"
                      Acineta
                      Zoothamnium

"Cnidarians"

"Flatworms"

"Nematodes"

"Gastrotrichs"
          Chaetonotus

"Annelids"
          Naidids

"Mollusks"
          Glochidia
          Corbicula fluminea

"Arthropods"