Rhynchobdellida, the jawless leeches or freshwater leeches, are an order of aquatic leeches. Despite the common name "freshwater leeches", species are found in both sea and fresh water. They are defined by the presence of a protrusible proboscis instead of jaws, and having colourless blood. They move by "inchworming" and are found worldwide. The order contains 110 species, divided into 41 genera and three families. Members of the order range widely in length, usually between 7 and 40 mm. They are hermaphrodite. The order is not monophyletic.
The Kinabalu giant red leech is a large bright orange-red coloured leech that is endemic to Mount Kinabalu, Borneo. It can grow to a length of over 50 cm (20 in).
Haemadipsidae are a family of jawed leeches. They are a monophyletic group of hirudiniform proboscisless leeches. These leeches have five pairs of eyes, with the last two separated by two eyeless segments. The family is monotypic, containing only the subfamily Haemadipsinae, though as the family can apparently be divided into two or three distinct lineages, at least one of the proposed splits, while not a distinct family, might be a valid subfamily.
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.
The Hirudiniformes are one of the currently-accepted suborders of the proboscisless leeches (Arhynchobdellida). Their best-known member is the European medical leech, Hirudo medicinalis, and indeed most of the blood-sucking "worms" as which leeches are generally perceived belong to this group. In general, though some leeches suck blood, many are predators which hunt small invertebrates.
Leeches are segmented parasitic or predatory worms that comprise the subclass Hirudinea within the phylum Annelida. They are closely related to the oligochaetes, which include the earthworm, and like them have soft, muscular segmented bodies that can lengthen and contract. Both groups are hermaphrodites and have a clitellum, but leeches typically differ from the oligochaetes in having suckers at both ends and ring markings that do not correspond with their internal segmentation. The body is muscular and relatively solid; the coelom, the spacious body cavity found in other annelids, is reduced to small channels.
Xerobdellidae are a small family of jawed leeches in the order Arhynchobdellida. Xerobdellidae have three jaws and five pairs of eyes, the fourth and fifth being separated by one or two eyeless segments. The genera placed herein occur in Chile (Mesobdella), Europe (Xerobdella) and Diestecostoma is found in Central and northern South America. This peculiar distribution strongly suggests they are a relict Pangaean group, which had already been present by the start of the Jurassic 250 million years ago.
Phytobdella catenifera is a large terrestrial leech found in Peninsular Malaysia. John Percy Moore chose this species’ epithet ‘catenifera’ after the striking chain-striped pattern on the creature's back.
Americobdella is a genus of carnivorous leeches from southern Chile, comprising only the species, Americobdella valdiviana.
Erpobdella is a genus of leeches in the family Erpobdellidae. Members of the genus have three or four pairs of eyes, but never have true jaws, and are typically 20–50 millimetres (0.8–2.0 in) long. All members do not feed on blood, but instead are predators of small aquatic invertebrates, which they often swallow whole.
Erpobdellidae is a family of leeches. It is one of the four families belonging to the suborder Erpobdelliformes of the proboscisless leeches order, Arhynchobdellida.
Orobdella masaakikuroiwai is a species of proboscisless leech from Japan.
Praobdellidae is a family of hematophagous leeches which live on the mucous membranes of mammals and sometimes invertebrates. These are internal parasites that enter the body through natural orifices, and cause hirudiniases.
Orobdella is a genus of leeches. It is the only genus in the monotypic family Orobdellidae. They are large annelids, with the largest species exceeding 20 cm (7.9 in) in length, but some are much smaller: mature individuals of Orobdella koikei can measure only 4 cm (1.6 in). They inhabit the banks of mountain streams and feed on earthworms. The majority of species are endemic to Japan; two species are known from Taiwan, one from Korea, and one from Russian Far East.
Orobdella ketagalan is a species of terrestrial leech in the order Arhynchobdellida, the proboscisless leeches. It is endemic to northern Taiwan. It is known from the vicinity of Taipei, including its type locality, Yangmingshan National Park. The specific name refers to the native Taiwanese Ketagalan people inhabiting the area. The closest known relative of Orobdella ketagalan is Orobdella meisai from southern Taiwan, followed by Orobdella dolichopharynx and Orobdella shimadae from the Ryukyu Islands (Japan).
Tritetrabdella is a genus of terrestrial hemataphagous leeches in the family Haemadipsidae. Unlike other haemadipsid leeches, Tritetrabdella species have four annuli on their mid-body segments. They have three jaws, with a total 45 teeth, and lack salivary papillae. Tritrabdella feeds primarily on amphibians and probably on small mammals as well, but to a lesser extent. Bornean species may be endangered due to amphibian population decline, disturbance and fragmentation of habitat, and climate fluctuations.
Tritetrabdella kinabaluensis is a species of terrestrial blood-feeding leech in the family Haemadipsidae. It has been observed exclusively from Sabah, Malaysia. The species is divided into two subspecies: Tritetrabdella kinabaluensis kinabaluensis and Tritetrabdella kinabaluensis inobongensis, the former being the typical subspecies. The species epithet derives from the sacred mountain Mount Kinabalu.
Haemadipsa rjukjuana is a species of terrestrial blood-feeding leach in the family Haemadipsidae. They are mostly found in Taiwan, although they have also been confirmed from Gageo Island in South Korea.
Macrobdella decora, also known as the North American medicinal leech, is a species of freshwater leech. It is found in much of eastern North America in freshwater habitats, although there is one disjunct population in northern Mexico. M. decora is both a parasite of vertebrates, including humans, and an aquatic predator of eggs, larvae, and other invertebrates.
