Leeches are indispensable organisms of aquatic ecosystems. More than 650 species of leech have been identified worldwide. These organisms are ecological importance of leeches live in freshwater, estuarine, marine, and semiterrestrial ecosystems. Leeches occur in slow-moving parts of streams and rivers, in artificial and natural lakes, in marine habitats, such as marshes and lakes. Leeches are found in benthic and occasionally pelagic communities of artificial and natural lakes, ponds, marine habitats such as marshes and lagoons, and slow-moving parts of streams and rivers. Some leech species are parasitic and mostly feed on predators. Some species of leech, which perform important functions in the ecosystem, are also at risk. Leeches, which are members of the Clitellata class, are foremost among the aquatic organisms affected by the negative environment. In particular, human-induced environmental pressures are the most important factors endangering the development of leeches. Leeches are most affected by agricultural activity, overharvesting, hazardous chemical compounds in water, increased urbanization, and global climate change.
- Introduction
Leeches are members of the phylum Annelida, which feed as bloodsuckers or as predators in wetlands. Worldwide, more than 650 species of Hirundine-class leeches have been identified in freshwater, estuarine, and semi-terrestrial ecosystems. With the development of genetic science, new leech species have been discovered in this class and changes in some known species names.1-5 Leeches are the most important and reliable indicators of water quality and ecosystem biodiversity. Therefore, the presence of specific species of leech is often closely related to the main water events and the presence of certain animals. However, leeches are largely ignored in many ecological and environmental research projects or simply identified as Hirudinea. 
Economical importance of leeches
Economical Importance to People from the leeches breeding's: Positive The medicinal leech, as its name suggests, has historically been used for medicinal purposes, primarily to remove "bad blood" from sufferers. Around 1850, this practice fell into disrepute, but H. medicinalis again had value in medicinal practices. Today, this species is used to relieve pressure and restore circulation in tissue grafts where blood tends to collect, such as amputated fingers and ears. Leech anticoagulant is also a fertile research area for operations where an incision must be kept open. In addition, the saliva of leeches has been found to contain powerful antibiotics and anesthetics that will undoubtedly be useful in future medical practice. Economic Importance to People: Negative The medicinal leech is a parasite of humans and is a source of unpleasant emotions for both leech victims and bystanders.
- State of conservation
The medicinal leech is rare throughout its range in Europe and is no longer present in much of its former range. This is largely due to the overharvesting of leeches in the last century for medicinal use. Other factors that contribute to the decline of the leech's state are the disturbance of its common. The medicinal leech, as its name suggests, has historically been used for medicinal purposes, primarily to remove "bad blood" from sufferers. Around 1850, this practice fell into disrepute, but H. medicinalis again had value in medicinal practices.
- Reproduction
- medicinalis breeds once a year from June to August. It also remains fertile for several years, unlike most other types of leech. The act of mating takes place on the ground, where a leech is ventrally attached to each other by a mucous secretion. All leeches are hermaphrodites and fertilization is internal. The sperm is injected into the vagina through an expandable copulatory organ. A cocoon forms around the clitellum and slips into the anterior section of the leech. The entire egg sac is deposited on moist soil, usually just above the shore. After about 14 days, the eggs hatch as fully developed miniature adults.
- Behavior
Motility is achieved both on land and in water. Hirudo medicinalis moves through the water by contracting the longitudinal muscles of the body in a wave-like motion that propels it forward through the water. Movement on the ground is achieved by "looping", a movement similar to that of inchworms. They adhere to the substrate alternately with their front and rear suckers. The leech sees the movement of the shadows above. Especially when "hungry" H. medicinalis will respond to moving shadows, which often indicate a mammalian food source. A dark shadow can also trigger an alarm response in the leech where it stops ventilating. Hirudo medicinalis is parasitic and the adults feed on the blood of mammals. It clings to the host with its two suction cups and bites the skin of its victim. At the same time, the leech injects an anesthetic so that its presence cannot be seen and an anticoagulant so that the incision remains open during feeding. It has three mandibles, which work back and forth during the feeding process, which usually lasts 20-40 minutes and leaves a tripartite star-shaped scar on the host. After a full meal of 10 ml to 15 ml of blood, the medicinal leech can grow to 8 to 11 times its initial body size. Leeches only feed once every six months, this is about the time it takes for the blood meal to be completely digested. Certain bacteria prevent blood from spoiling during long periods of digestion. H. medicinalis can go more than six months without eating by digesting its own tissues. Young leeches feed on frogs rather than mammals because their jaws are not yet strong enough to break mammalian skin. 
Ecological disadvantages of leeches
Did you know Leeches in ecological disadvantages that can be useful as an indicator of environmental quality of leeches. Today, we're lifting the veil on the secret sex lives of leeches and how researchers at McMaster University and Fisheries and Oceans Canada are using that information to learn about endocrine-disrupting chemicals. Rising to worldwide fame when they made their film debut in the blockbuster "Stand by Me" in 1986, the leeches have been around for a really long time. They are found on all continents in freshwater habitats where there is little flow. They are a popular fishing bait and continue to be used by doctors in medical treatment. We know a lot about breeding leeches. For example, leeches are hermaphrodites, meaning they have both male and female sex organs, but that's not uncommon among invertebrates. Some leech families exhibit protrandry (starting life as males and later becoming females), while others self-fertilize, lay eggs, and exhibit parental care. Others cross-fertilize with other leeches, sometimes implanting sperm in one or both of the partner's body walls, and sometimes injecting sperm directly into the genital opening of the partner. Their reproductive cycle also varies between families, with some breeding only once in their lifetime and others breeding multiple times in their lifetime. 
We also know little about the effect of environmental pollutants on leeches. In fact, leeches have been shown to be extremely sensitive to metals in water systems. Leeches can be useful as an indicator of environmental quality, as the aquatic ecosystems in which leeches are found are often sinks for pollutants. However, although studies have looked at how certain environmental contaminants affect leech populations, little is known about how they influence leech community composition, species abundance, egg production, growth rates, and the size of the gonads. For example, several studies have been conducted at the Lakes Experimental Area in Ontario, Canada, to study the effects of synthetic estrogen (17α-estradiol [EE2]) on fish, other invertebrates, and amphibians. Synthetic estrogens are used in oral contraceptives and enter aquatic systems when not completely broken down in sewage treatment plants. The compound EE2 has been shown to have profound effects on fathead minnows, collapsing their population and occasionally affecting amphibian hatching success and gonad development. However, little attention has been paid so far to the impact of EE2 on leech communities. 
Leech therapy
What is leech therapy? Since the time of ancient Egypt, leeches have been used medicinally to treat nervous system abnormalities, dental problems, skin diseases, and infections. Today, they are mainly used in plastic surgery and other microsurgery. This is because leeches secrete peptides and proteins that work to prevent blood clots from forming. These secretions are also known as anticoagulants. It keeps blood flowing to wounds to help them heal. Currently, leech therapy is making a comeback because of its simple and inexpensive way to prevent complications. How does leech therapy work? Medicinal leeches have three jaws with small rows of teeth. They pierce a person's skin with their teeth and inject the anticoagulants through their saliva. The leeches are allowed to draw blood, 20 to 45 minutes at a time, from the person undergoing treatment. This is equivalent to a relatively small amount of blood, up to 15 milliliters per leech. Medicinal leeches usually come from Hungary or Sweden. There are several situations where leech therapy can be used. People who may benefit include those at risk of amputation due to side effects of diabetes, those diagnosed with heart disease, and those undergoing cosmetic surgery where they are at risk. to lose some of it. soft tissue. Therapy is also recommended to treat blood clots and varicose veins. 
People with anemia, blood clotting conditions, or compromised arteries are not candidates for leech therapy. Children under 18 and pregnant women are also often advised to avoid it.
- Medical Applications for Leech Therapy
During a session, live leeches attach to the target area and draw blood. They release proteins and peptides that thin the blood and prevent clotting. It improves circulation and prevents tissue death. Leeches leave small Y-shaped sores that usually heal without scarring. Leeches are effective in increasing blood circulation and breaking down blood clots. It should not be surprising that they can be used to treat circulatory disorders and cardiovascular diseases. Chemicals derived from leech saliva are made into medicines that can treat. 
Fun facts about leeches
- 4 Amazing Things About Leeches
Most fun facts about people loathe leeches. But a closer look reveals that they are fascinating and surprisingly beautiful little creatures. Here are five surprising facts about leeches and the people who love them.
- Leeches are not black or slimy
The skin of hirudo medicinalis, the type of leech used medicinally, is green with orange and yellow spots. And it is sticky to the touch.
- Leeches are FDA approved
After surgeons reattach a severed finger or earlobe, they may use leeches to stimulate blood flow and keep the limb from being starved of oxygen. The FDA approved leeches for these uses in 2004
- Leech anatomy is crazy
Each leech contains: ten eyes, six hearts, 10 blood storage bags, 32 brains, and 200 enzymes to keep the blood coagulated for the three months it takes to digest a meal.
- Leeches aren't really 'medieval
Its medicinal use began in India 5,000 years ago and reached its peak in France in the mid-19th century.
- Most medical leeches are Welsh
Bio pharm, a Welsh company, is the largest supplier of medical leeches in the United States, selling about 40,000 leeches a year here. 
Are leeches' parasites
Leeches. Most leeches (class of annelids Hirudinea) are blood-sucking parasites that attach to vertebrate hosts, bite into the skin and suck large amounts of blood. Apart from the nuisance effect of their bites, their medical significance is usually minimal.
- Arthropods, tongue worms, leeches and arthropod-borne diseases
- Leeches
Most leeches (class of annelids Hirudinea) are blood-sucking parasites that attach to vertebrate hosts, bite into the skin and suck large amounts of blood. Apart from the nuisance effect of their bites, their medical significance is usually minimal. When feeding, leeches release an anticoagulant (hirudin) that helps ensure a complete blood meal. Leeches vary in shape from elongated cylindrical to broadly ovoid, and may be black, brightly colored, or spotted; they have muscular suckers on their anterior and posterior ends. Its dorsal side is convex and the ventral side is flattened. Leeches have outer rings (segments) like other annelids, but differ in that they do not have setae or appendages. They are hermaphrodites. The length varies from a minute (5 mm long) to a giant (45 cm long). Many different groups or types of leeches occur throughout the world. Known freshwater leeches become parasitic on humans or animals that visit the muddy bottoms of rivers or lakes. External attachment of leeches is often called external hirudiniasis. 
The famous medicinal leech, Hirudo medicinalis, a freshwater worm about 10 cm long, was often used in the 18th century as a blood vessel. Bloodthirsty terrestrial leeches live in hot, humid areas of South America and Southeast Asia. Terrestrial or ground leeches typically live in tropical rainforests, where they can be found on rocks, bushes, and leaves. Some leeches become attached when people drink contaminated water, settling in the digestive or upper respiratory tract. "Horse leeches" may attach to the pharynx or nasal passages of horses or people drinking water from infested ponds or streams in the Middle East or North Africa. The internal leech, Limnatis nilotica, is found in southern Europe, northern Africa, and western Asia, where it can adhere to the mucous membranes of the pharynx, nasopharynx, and esophagus. People with L. nilotica infestation often have epistaxis, hemoptysis, or hematemesis. Treatment of leech infestation usually involves only mechanical removal of the maggots. The victim often does this without medical advice. However, leech infestation in the nasopharynx, airways, or esophagus is usually curable by endoscopic removal.