Taxonomic information: sludge worms

the root (no rank)
   Eukaryota (domain)
      Metazoa (kingdom)
         Annelida (phylum)
            Oligochaeta (class)
               Haplotaxida (order)
                  Tubificina (suborder)
                     Tubificidae (family)
                        sludge worms (common name)
                           [hide inferior taxa]

Another query: