![]() The paper includes also data about hosts and habitats, distribution in the world and in Tunisia. They belong to 2 orders, 2 suborders, 4 families and 11 genera. In this study 13 leech species from Tunisia are listed. Hirudinea, Checklist, leeches, geographic distribution, Tunisia, identification key. Use of this website means you agree to all of the Legal Terms and Conditions set forth by the owners.Université de Tunis El Manar, Faculté des Sciences de Tunis No images, graphics, software, scripts, or applets may be reproduced or used in any manner without permission from the copyright holders. Davidson - National High Magnetic Field Laboratory, 1800 East Paul Dirac Dr., The Florida State University, Tallahassee, Florida, 32310.īACK TO THE DIGITAL IMAGE GALLERIES Questions or comments? Send us an email. During a flood or with normal outflow of a lake or downstream flow in a stream, leeches can quickly take hold and become abundant in a new habitat.Ĭynthia D. Leeches are hermaphrodites, as are other annelids, and the fertilized eggs and encapsulated cocoons are attached to aquatic plants and leaves. The most common is to remain attached to an animal such as a migrating fish, wading bird, or turtle, or an inanimate object such as a log as it moves to another location. Research is also being conducted on leech saliva for its possible anti-cancer properties. Attaching leeches to the affected area effectively removes the old blood until the outgoing blood vessels have healed. Often, blood can flow into the tissue but cannot flow out because of swollen, blocked veins. Today, leeches are used after microsurgery to reduce blood congestion in damaged tissue. This leech craze contributed to the depletion of the European population of medicinal leeches. A common treatment for headaches, predating aspirin, was to apply several leeches to each temple and allow them to remove the "tainted" blood. ![]() It was used to treat many ailments such as pain, skin disorders, and high blood pressure. This anticoagulant is called hirudin and has been used for medicinal purposes for centuries.įirst described in Ancient Greece, "blood-letting" with the aid of leeches reached its maximum popularity in nineteenth century Europe. In addition, the leech's saliva dilates the blood vessels to increase blood flow and prevent the blood from clotting. When the leech punctures the skin it anesthetizes the wound with its saliva, so that often the victim doesn't feel the puncture. The mouth is located on the small sucker and has three jaws with sharp teeth that make a Y-shaped incision in the flesh. Parasitic leeches are equipped with a large (caudal) and a small (oral) sucker. A leech can hold up to three times its weight in blood. Blood-feeding leeches retain the solid parts of the blood as food in their very large crops, while the leech's kidneys eliminate the blood fluid. While many aquatic leeches feed on the blood of fishes, amphibians, birds, mammals, snails, insect larvae, and worms, true land leeches feed only on the blood of mammals. Most leeches are negatively phototropic, very sensitive to movement in the water, and locate potential prey and mates by chemoreception. Aquatic leeches can swim in an undulating fashion resembling movement of a ribbon, or crawl by looping, but land leeches move over solid surfaces by muscular expansion and contraction. They do not have gills or lungs, but rather breath through their skin. Leeches are found most often in stagnant freshwater ponds, but can also be found on land and in saltwater habitats. View a high magnification image of a leech. Although commonly known as the bloodsuckers, some species are not parasitic and are free-living in streams and ponds, feeding on aquatic insects and other freshwater invertebrates. Leech is a common name for over 650 species of largely freshwater, carnivorous worms that comprise the class Hirudinea in the phylum Annelida. Molecular Expressions: Science, Optics & You - Olympus MIC-D: Darkfield Gallery - Leeches
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