fish
inverts
   Arthropoda
     Arachnida
     crustacea
       altocrustacea
       argulus
       crabs
       crayfish
         Barbicambarus
         Cambarellus
         Cambarus
           englishi
           manningi
           rusticiformis
           scotti
         Cherax
         Euastacus
         Hobbseus
         Lacunicambarus
         Pacifastacus
         Procambarus
       fairy shrimp
       mutations
       ostrocoda
       shrimp
     insecta
   bacteria
   cnidaria
   colonial
   gastropods
   molluscs
   protists
   worms
misc
plants