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Leeches either have a pharynx that they can protrude, commonly called a proboscis, or a pharynx that they cannot protrude, which in some groups is armed with jaws. [38] In the proboscisless leeches, the jaws (if any) of Arhynchobdellids are at the front of the mouth, and have three blades set at an angle to each other.
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.
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. [1]
Oligochaetes have a sticky pad in the roof of the mouth. [8] Most are burrowers that feed on wholly or partly decomposed organic materials. [13] Hirudinea, whose name means "leech-shaped" and whose best known members are leeches. [8] Marine species are mostly blood-sucking parasites, mainly on fish, while most freshwater species are predators. [13]
Aquatic leeches have been found on sites such as the nose, mouth, pharynx, larynx, conjunctiva, trachea, bronchi, esophagus, vagina, bladder, rectum, and the creases of the eyes, [4] Although most instances were found in the nasopharynx, lower airways, or upper esophagus. Humans become victims from bathing or drinking unfiltered water in less ...
Leeches are hermaphrodites, and mating may take place on or off the fish host, but in either case, the cocoon, usually containing a single egg, is deposited elsewhere, usually stuck to a stone or piece of vegetation, or even to the carapace of a crustacean. When the egg hatches, the juvenile leech has about a week to find a suitable fish host ...
The leech sometimes emerges from the water to hunt for earthworms. [4] [7] Like other leeches, Haemopis sanguisuga is a hermaphrodite. The testes mature first and the ovaries later in the organism's life. A pair of leeches will line up with the clitellar regions in contact, and sperm is passes by the one acting as male to the female gonopore.
Leeches, order Hirudinida, [4] mostly have flattened bodies, usually tapered at both ends. They have a fixed number of segments, 33, but the segmentation is not visible externally because the cuticle is marked with annulations. Leeches do not bear chaetae. The front few segments or head have been modified into a sucker that usually surrounds ...