English: leeches.
Genera:
Phyla,
Sipuncula,
Hyolitha †,
Nemertea,
Phoronida,
Bryozoa,
Entoprocta,
Brachiopoda,
Mollusca,
Annelida,
Echiura.
Zoology: leeches as a sub-group of oligochaetes and oligochaetes as a sub-group of polychaetes. In addition, the Pogonophora,
Echiura and
Sipuncula, previously regarded as separate phyla, are now regarded as sub-groups of polychaetes. Annelids are considered members of the
Lophotrochozoa, a "super-phylum" of protostomes that also includes molluscs, brachiopods, flatworms and nemerteans.
TaxonomyThese are the worms in all kinds of forms. They have a bilateral symmetry and 3 germ layers, which is called triploblastic.
The traditional classification:Polychaetes, almost all marine.
Oligochaetes, include earthworms.
Leech-like species.
Phase 7Or
Class
Polychaeta.
Class
Clitellata:
Oligochaeta, earthworms.
Branchiobdellida Hirudinea, leeches
Class Myzostomida
Class Archiannelida (polyphyletic)
Class
Echiura, previously a separate phylum)