- Rhynchobdellida
Taxobox
name = Jawless leeches
regnum =Animalia
subregnum =Eumetazoa
phylum =Annelida
classis =Clitellata
subclassis =Hirudinea
infraclassis =Euhirudinea
ordo = Rhynchobdellida
ordo_authority = Blanchard, 1893
subdivision_ranks = Families
subdivision =Glossiphoniidae Ozobranchidae (disputed)Piscicolidae Rhynchobdellida, the jawless leeches, are classified as an order of the
Hirudinea . But leechtaxonomy andsystematics will eventually be revised in due time, not because there are many uncertainties about theirphylogeny , but because the majorclade s of clitellateannelid s - and whether the clitellates are themselves a clade - have not been fully elucidated. For example, the "true leeches" (Euhirudinea ) might actually be synonymous with the Hirudinea, as all other leech-like annelids might not be very closely related to the true leeches.Compared to their
sister taxon , theArhynchobdellida (proboscisless leeches), rhynchobdellidsystematics has always been rather straightforward as regards the mainclades contained therein. The common name is actually misleading however, as jawlessness is a primitive trait among leeches in general - most Arhynchobdellida are in fact jawless too. It is rather the proboscis that is the characteristicapomorph y of the Rhynchobdellida.Two or three families are recognized: The
Glossiphoniidae arefreshwater leeches, flattened, and with a poorly defined anterior sucker. ThePiscicolidae occur inseawater , have cylindrical bodies, and a usually well-marked, bell-shaped, anterior sucker. TheOzobranchidae are not universally accepted as distinct; some authors prefer to merge them with the Piscicolidae.
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