Jawless leeches | |
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Branchellion parkeri | |
Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Annelida |
Class: | Clitellata |
Subclass: | Hirudinea |
Infraclass: | Euhirudinea |
Order: | Rhynchobdellida Blanchard, 1893 |
Families | |
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Rhynchobdellida (from the Greek rhynchos, mouth, and bdellein, sucking), [1] the jawless leeches[ citation needed ] or freshwater leeches, [2] are an order of aquatic leeches. [3] [4] 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. [5] [6] [7] They move by "inchworming" [8] and are found worldwide. The order contains 110 species, divided into 41 genera and three families. [8] Members of the order range widely in length, usually between 7 and 40 mm. [2] They are hermaphrodite. [2] The order is not monophyletic. [9]
Instead of jaws and teeth, Rhynchobdellidae have protrusible proboscises, which they use to penetrate the host's skin. [2] [10] Mouths of Rhynchobdellidae species are small holes from which the proboscis can be protruded. [10] The proboscis then sucks out the desired bodily fluid from the host: usually blood or coelomic fluid in the case of invertebrate victims. [9]
Rhynchobdellidae are either sanguivorous or predatory.[ citation needed ] Sanguivorous species usually feed on a variety of other animals, using their proboscis to host's skin. They generate anticoagulants (like mosquitoes) and natural anaesthetia to help the feeding. [2] Predatory Rhynchobdellidae have digestive enzymes that help break down their prey, which usually consists of small invertebrates such as insect larvae or amphipods. [2]
The Glossiphoniidae, the freshwater jawless leeches,[ citation needed ] or leaf leeches (due to their shape) [11] are freshwater leeches, flattened, and with a poorly defined anterior sucker. [2] The family Glossiphoniidae contains one of the world's largest species of leech, the giant Amazon leech, which can grow up to 45 cm in length. [12] Many species show extended parental care, keeping eggs in nests or pouches and caring for and feeding the young. [2] [13] They feed on both vertebrate and invertebrate animals. [4]
The Piscicolidae occur in both freshwater and seawater, have cylindrical bodies, and a usually well-marked, bell-shaped, anterior sucker. [2] [4] They are parasites of fish. [11] [4] The family was originally divided into three subfamilies based on species' pulsatile vesicles, but the subfamilies were disbanded in 2006. [4]
Ozobranchidae are primarily parasitic on marine turtles, and are sometimes merged with the Piscicolidae. [2] [4]
The family Argulidae, whose members are commonly known as carp lice or fish lice, are parasitic crustaceans in the class Ichthyostraca. It is the only family in the monotypic subclass Branchiura and the order Arguloida, although a second family, Dipteropeltidae, has been proposed. Although they are thought to be primitive forms, they have no fossil record.
The Clitellata are a class of annelid worms, characterized by having a clitellum – the 'collar' that forms a reproductive cocoon during part of their life cycles. The clitellates comprise around 8,000 species. Unlike the class of Polychaeta, they do not have parapodia and their heads are less developed.
Erpobdella obscura is a freshwater ribbon leech common in North America. It is a relatively large leech and is commonly used as bait by anglers for walleye and other sport fish. In Minnesota, live bait dealers annually harvest over 45,000 kg of bait-leeches, raising concerns of over-harvest.
Helobdella is a genus of leeches in the family Glossiphoniidae, the freshwater jawless leeches. They occur worldwide.
Insects have mouthparts that may vary greatly across insect species, as they are adapted to particular modes of feeding. The earliest insects had chewing mouthparts. Most specialisation of mouthparts are for piercing and sucking, and this mode of feeding has evolved a number of times idependently. For example, mosquitoes and aphids both pierce and suck, though female mosquitoes feed on animal blood whereas aphids feed on plant fluids.
Euhirudinea, the true leeches, are an infraclass of the Hirudinea.
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.
Glossiphoniidae are a family of freshwater proboscis-bearing leeches. These leeches are generally flattened, and have a poorly defined anterior sucker. Most suck the blood of freshwater vertebrates like amphibians, crocodilians and aquatic turtles, but some feed on invertebrates like oligochaetes and freshwater snails instead. Although they prefer other hosts, blood-feeding species will opportunistically feed from humans.
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 in having ring markings that do not correspond with their internal segmentation. The body is muscular and relatively solid, and the coelom, the spacious body cavity found in other annelids, is reduced to small channels.
The digestive system of gastropods has evolved to suit almost every kind of diet and feeding behavior. Gastropods as the largest taxonomic class of the mollusca are very diverse: the group includes carnivores, herbivores, scavengers, filter feeders, and even parasites.
Haemopis sanguisuga is a species of freshwater leech in the family Haemopidae. It is commonly called the horse-leech, but that is due to the similarity of its appearance to the leech Limnatis nilotica, which sometimes enters the nasal cavities of livestock. Haemopis sanguisuga does not behave in this way. Another synonym for this leech is Aulastomum gulo.
Branchiobdellida is an order of freshwater leech-like clitellates that are obligate ectosymbionts or ectoparasites, mostly of astacoidean crayfish. They are found in the Northern Hemisphere and have a holarctic distribution in East Asia, the Euro-Mediterranean region and North and Central America, with the greatest species diversity being in North and Central America.
Erpobdella octoculata is a freshwater leech in the Erpobdellidae family. This species can be found in Europe, the Mediterranean, and the Middle East.
Hemibdella soleae is a marine species of leech in the family Piscicolidae and the type taxon of its genus. Found in the northeastern Atlantic Ocean, it is a parasite of flatfish such as the common sole.
The Piscicolidae are a family of jawless leeches in the order Rhynchobdellida that are parasitic on fish. They occur in both freshwater and seawater, have cylindrical bodies, and typically have a large, bell-shaped, anterior sucker with which they cling to their host. Some of the leeches in this family have external gills, outgrowths of the body wall projecting laterally, the only group of leeches to exchange gases in this way.
Acanthobdella peledina is a species of leech-like clitellate in the order Acanthobdellida. It feeds on the skin and blood of freshwater fishes in the boreal regions of northern Europe, Asia and North America.
Theromyzon tessulatum is a species of leech in the family Glossiphoniidae. It is a haematophagous (blood-sucking) leech, found in freshwater habitats in Europe.
Placobdelloides is a genus of glossophoniid leeches.
Pontobdella muricata is a species of marine leech in the family Piscicolidae. It is a parasite of fishes and is native to the northeastern Atlantic Ocean, the Baltic Sea, the North Sea, and the Mediterranean Sea.
Myzobdella lugubris, the crab leech, is a species of jawless leech widespread in North America, especially in central and Eastern Canada. It is an ectoparasite of fish and crustaceans, and is responsible for several dangerous conditions in fish, including lesions infected by bacteria and fungi and possibly viral hemorrhagic septicemia. It lays its egg capsules on crabs and possible other arthropods, which then disperse the eggs.