Arhynchobdellida, the proboscisless leeches, are a monophyletic order of leeches. They are defined by the lack of the protrusible proboscis that defines their sister taxon, the Rhynchobdellida.[1][2][3] Arhynchobdellida is a diverse order, compromising both aquatic and terrestrial, besides sanguivorous and predatory, leeches.[3] The order is divided into two suborders, Erpobdelliformes and Hirudiniformes (sometimes also called the Pharyngobdelliformes and Gnathobdelliformes, respectively).[1]
Historically, the Arhynchobdellida were split into two orders, the Gnathobdellida and the Pharyngobdellida.[4] The Gnathobdellida were jawed and carnivorous or parasitic while the Pharyngobdellida were jawless and carnivorous.[5][6] Current taxonomy accepts the order Arhynchobdellida and divides into two suborders. There are 215 species of Arhynchobdellid leech, in 47 genera and 13 families.[7] The placement of Americobdellidae is uncertain; it has rudimentary jaws and is terrestrial.
Erpobdelliformes are jawless predators of aquatic invertebrates of varying sizes, including insect larvae, mollusks, and other annelids.[8][9] Unlike other leeches, they do not penetrate the skin of hosts; and are not at all parasitic.[10][11] The pharynx is spirally twisted and very large to allow for large prey; it can constitute up to one third of the leech's body length.[1]
Hirudiniformes are a diverse suborder defined by the presence of toothed jaws.[1][11]
Americobdellidae ?
Terrestrial, jawed*, carnivorous
Erpobdellidae
Aquatic, jawless, carnivorous
Salifidae
Aquatic, jawless, carnivorous
Americobdellidae ?
Terrestrial, jawed*, carnivorous
Cylicobdellidae
Terrestrial, jawed, carnivorous
Haemadipsidae
Terrestrial, jawed, almost all sanguivorous
Haemopidae
Semi-aquatic, jawed, sanguivorous
Hirudinidae
Terrestrial, jawed, carnivorous
Praobdellidae
Aquatic, jawed, sanguivorous
Xerobdellidae
Terrestrial, jawed, sanguivorous
Arhynchobdellida, the proboscisless leeches, are a monophyletic order of leeches. They are defined by the lack of the protrusible proboscis that defines their sister taxon, the Rhynchobdellida. Arhynchobdellida is a diverse order, compromising both aquatic and terrestrial, besides sanguivorous and predatory, leeches. The order is divided into two suborders, Erpobdelliformes and Hirudiniformes (sometimes also called the Pharyngobdelliformes and Gnathobdelliformes, respectively).
